Scientific Poster Session (Abstracts)

Scientific Poster Session SCIENTIFIC POSTER SESSION Thursday, September 13, to Saturday, September 15

POSTER 1

chemoembolization with encased-cisplatin ethylcellulose microspheres. AJNR Am J Neuroradiol 16:1037, 1995 Tomura N, Kobayashi M, Hirano J, et al: Chemoembolization of head and neck carcinoma with carboplatine microcapsules. Acta Radiol 37:52, 1996 Okamoto Y, Konno A, Togawa K, et al: Arterial chemoembolization with cisplatin microcapsules. Br J Carcinoma 53:369, 1986

Treatment of Oral Squamous Cell Carcinoma With Transcatheter Arterial Chemoembolization—Pathological Observation

Funding Source: Guangdong province scientific research fund, P.R. China.

Weizhong Li, DDS, Department of Oral and Maxillofacial Surgery, Nanfang Hospital, First Military Medical University, Guangzhou, Peoples Republic of China (Tong Zhao, MD, PhD; Zhubin Ma, MD)

POSTER 2

Purpose: Many clinical studies have shown that transcatheter arterial chemoembolization (TACE) can increase the surgical chance and survival rate for patients with oral carcinoma in late stages. The purpose of this study was to observe the pathologic changes of oral carcinoma produced by TACE, and to evaluate its therapeutic efficacy for advanced oral carcinoma. Method: Twenty cases (16 in the tongue, 2 in the gingiva, and 2 in the floor of the mouth) were observed in this study. All were intubated with Seldinger’s technique from the femoral artery to the external carotid artery. Under DSA technique, cisplatin, Adriamycin, and mitomycin C were injected into the branch of the external carotid artery to the carcinoma involved tissues and then injected into the gelatin sponge to produce embolization. Operations were performed 2 weeks later. The specimens were observed with microscopy and TEM. Result: Obvious changes occurred in the tumor tissue such as the decrease in amount of carcinoma cells, karyopyknosis, vacuolar degeneration, and focal coagulation necrosis. The disintegrated carcinoma nests were encapsulated and organized by the hyperplastic fibroconnective tissue as well as inflammatory cell infiltration. The connective structures between carcinoma cells had disappeared and this resulted in broadening the space between cells. Conclusion: Preoperative administration of arterial chemoembolization will lead to the degeneration and necrosis of oral carcinoma. This is helpful to distinguish the carcinoma from normal tissue, especially in that at late stages. References Kan Z, Sato M, Ivancev K, et al: Distribution and effect of iodized poppyseed oil in the liver after hepatic artery embolization: Experimental study in several animal species. Radiology 186:861, 1993 Tateishi H, Kinuta M, Furukawa J, et al: Follow-up studies of combination therapy for unresectable hepatocellular carcinoma. Carcinoma Chemother Pharmacol 33:S119, 1994 (suppl) Yang J, Ma XC, Zou ZJ, et al: Experimental maxillofacial arterial

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A Study of Cancellous Bone Area in the Mandibular Ramus Related to the Medial Osteotomy of the Sagittal Split Ramus Osteotomy Toshitaka Muto, DDS, PhD, First Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, 061-0293, Japan (Kimiharu Shigeo, DDS; Keiko Yamamoto, DDS; Johji Kawakami, DDS, PhD; Masaaki Kanazawa, DDS, PhD) Purpose: The objective of this study was to investigate the cancellous bone area in mandibular ramus of the patients of prognathism using CT scanning. Patients and Methods: Horizontal CT scans (Hitachi W 200) of 33 skeletal Class III patients (11 males and 22 females) and 30 control subjects without dentofacial deformity (15 males and 15 females) were evaluated. CT scans obtained were measured at the following 3 planes: just above the lingula, between the mandibular notch and the lingula, and just below the mandibular notch. At each plane, cancellous bone area was measured and it was decided whether or not the area of cancellous bone was separated. Finally, the type classification of cancellous bone area in the mandibular ramus from lingula to mandibular notch was made. Results: Morphology of cancellous bone area at each section was classified into 2 categories of cancellous bone: with separation and without separation. The cancellous bone with separation at lingula were 12% in the patient group and 2% in the control group, and that at mandibular notch were 32% in the patient group and 70% in the control group. Referring to the morphology of cancellous bone area at each section, the type classification was carried out on existence range of cancellous bone in the ramus from lingula to mandibular notch. It was possible to classify into 5 types. Conclusion: The mandibular ramus in the patient group was thinner and had a more complicated existence range of the cancellous bone than control group. AAOMS • 2001

Scientific Poster Session References Smith B, Rajchel JL, Waite DE, et al: Mandibular ramus anatomy as it relates to the medial osteotomy of the sagittal split ramus osteotomy. J Oral Maxillofac Surg 49:112, 1991 Tom WK, Martone CH, Mintz SM: A study of mandibular ramus anatomy and its significance to sagittal split osteotomy. Int J Oral Maxillofac Surg 26:176, 1997

POSTER 3 Scoring Grid as Alternative Evaluation Instrument in Accreditation Review of OMS Programs Catherine A. Horan, PhD, Commission on Dental Accreditation, 211 E Chicago Ave, Chicago, IL 60611 (Gene A. Kramer, PhD; Karen M. Hart, MA; Henry W. Fields, Jr, DDS, MS, MSD) During 1998 and 1999, the Commission on Dental Accreditation conducted a pilot study to determine whether a Grid evaluation instrument might afford a more objective determination of an oral and maxillofacial surgery (OMS) program’s accreditation status and enhance calibration among site visitors. The study compared the Grid evaluation instrument with the traditional evaluation instrument of the “Consultant Evaluation Report (CER)” using the 37 OMS programs scheduled for site visits during the period of the study. The Grid evaluation instrument was comprised of a series of statements from the standards rated on a scale of 1 to 5 by the site visitor. The CER was a listing of standards rated for compliance as Yes/No. Working in teams of 4 site visitors (2 on the Grid and 2 on the CER) for each visit, 6 data sets were collected per program—3 forms (1 consensus and 2 individual) for each evaluation instrument. For reliability, the variability in site visitor ratings within and across programs was analyzed. Findings showed the relationship of within-program to across-program variability was superior for the Grid evaluation instrument. A comparison of selected areas of the standards using both evaluation instruments demonstrated general agreement between both evaluation instruments. Based on final results of the study, the Commission approved the Grid scoring instrument for the accreditation evaluation of OMS programs, effective November 1, 2000. To date, this Grid evaluation instrument is the only one of its kind in specialized programmatic accreditation of higher education. References “Consultant Evaluation Report Form, Oral and Maxillofacial Surgery,” Commission on Dental Accreditation, 1998-1999 “Grid Scoring Instrument, Oral and Maxillofacial Surgery (Documents I-IV),” Commission on Dental Accreditation, 1998-1999 Funding Source: Commission on Dental Accreditation of American Dental Association.

AAOMS • 2001

POSTER 4 Chromosomal Changes in BetelAssociated Oral Carcinomas and Their Relation With Clinical Pathological Parameters Daniel Y-K Wong, BDS, MS, Taichung Veterans General Hospital, Department of Dentistry, Taichung, Taiwan, 40705, Republic of China (Shu-Chun Lin, PhD; KuoWei Chang, BDS, PhD) Background: Oral squamous cell carcinoma associated with betel use is a prevalent disease in Southeast Asian countries, including Taiwan. The chromosomal imbalances and their clinical implications in this subset of oral carcinoma were largely obscure. Materials and Methods: We performed chromosomal analysis by comparative genomic hybridization on 47 patients with this disease from Taiwan within 1996 to 1998. The parameters were examined by t-test, Fisher’s exact test, or Kaplan-Meier survival analysis to identify their implications in oral oncogenesis. Results: Two thirds (31/47) of the cases exhibited detectable chromosomal imbalances with the remainder exhibiting normal karyotypes. The most common overrepresented chromosome arms were 8q (32%), 9q (26%), 11q (23%), 17q (21%), and 7p (17%) and the minimal overlapping regions for these were at 8q24, 9q34, 11q13, 17q21, 17q25, and 7p22. The most frequent losses were at chromosomal arms 3p (34%), 4q (23%), 5q (19%), 9p (15%), and 18q (13%) and these mapped to 3p14-26, 3p12-14, 4q12-36, 5q15-23, 9p2123, and 18q21-23. The parameters significantly associated with the numbers of chromosomal gains, losses, and total imbalances per tumor were the age of the patients and nodal metastasis (P ⫽ .03 to P ⬍ .01). The preliminary findings of a lower incidence of gain of 8q and loss of 4q in betel-associated oral carcinomas compared to non– betel-associated tumors provided insight into the effect of betel on oral carcinogenesis. Deletion of 3p and gain of 11q alterations were more prevalent in carcinomas with lymph node metastasis than in nodenegative tumors (P ⫽ .02), and thus it can be proposed that these events may lead to tumor progression. Losses of 3p and 4q and gain of 9q were associated with the poor outcomes for tumors (P ⫽ .03 to P ⬍ .01). Conclusion: Our data provided a first comprehensive insight into the cytogenetic changes in betel-associated oral carcinomas and demonstrated that the frequent aberrations in 4q and 9q sites can be used as novel prognostic predictors. References Kallioniemi A, Kallioniemi OP, Sudar D, et al: Comparative genomic hybridization for molecular cytogenetic analysis of solid tumors. Science 258:818, 1992

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Scientific Poster Session Rooney PH, Murray GI, Stevenson DA, et al: Comparative genomic hybridization and chromosomal instability in solid tumours. Br J Cancer 80:862, 1999 Funding Source: Taichung Veterans General Hospital.

POSTER 5 Proliferative Verrucous Leukoplakia: The Histologic Progression of a High-Risk Precancerous Lesion Bret L. Betterman, University of Minnesota School of Dentistry, 16-116 Moos Tower, 515 Delaware St SE, Minneapolis, MN 55455 (Michael D. Rohrer, DDS, MS) A specific type of leukoplakia, proliferative verrucous leukoplakia (PVL), was first described in 1985 by Hansen et al as a particular form of leukoplakia which presents initially as a simple hyperkeratosis but it maintains a very aggressive clinical course, spreading locally, or becoming multifocal. PVL is persistent, appears to be resistant to treatment, and has a very high risk for malignant transformation. Diagnosis in its early stages is difficult. To better understand the histologic progression and clinical features of PVL, we screened records from our surgical oral pathology service for patients who had had multiple biopsies for recurrent leukoplakic lesions and verrucous hyperplasia between 1997 and 2000. Previous specimens from these patients were reviewed back to 1992. Twenty-nine patients were selected whose clinical and histologic presentation appeared to be consistent with PVL. All of the histological specimens available for these patients were coded and examined by an oral and maxillofacial pathologist who had not been involved with the original diagnoses. Lesions were scored according to the severity of their histologic appearance on a scale of 1 to 10 according to the progression proposed by Hansen et al. The degree of inflammation for each specimen was scored on a scale of 0 to 2; 0 being little or no inflammation and 2 being severe inflammation. We examined 127 biopsies. The mean number of biopsies per patient was 4.38 (range, 2 to 12). Patient age at first biopsy ranged from 26 to 87 (mean age, 65.9). Nearly two thirds of the patients in this study were female. Biopsy grade, based on the system proposed by Hansen et al, ranged from 2 to 10 with a mean grade of 5.40. Patients showed a significant tendency to increase in biopsy grade by an average of 0.54 grades per biopsy. This was consistent even for patients who had only a few biopsies. Inflammatory grades for the patients ranged from 0 to 2 with a mean grade of 0.97. High mean inflammation grade correlated significantly with a high biopsy grade. Patients with an initial inflammation score of 2 were significantly more likely to have a biopsy grade of 7 or higher than were patients who presented with an inflammation score of 0 or 1. The most common sites of 100

PVL in this study were the mandibular alveolar mucosa followed by lateral tongue, floor of the mouth, maxillary gingiva, and others. This study supports PVL as a distinct clinical entity with aggressive clinical progression and resistance to conventional treatment of leukoplakic lesions. It also introduces the intensity of inflammation as a factor to consider in the diagnosis of PVL. Recognition of both the clinical and histologic features of PVL are essential to ensure proper treatment, including longterm follow-up. References Hansen LS, Olson JA, Silverman S Jr: Proliferative verrucous leukoplakia. Oral Surg Oral Med Oral Pathol 60:285, 1985 Silverman S Jr, Gorsky M: Proliferative verrucous leukoplakia: A follow-up study of 54 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 84:154, 1997

POSTER 6 Bilateral Tumors of the Major Salivary Glands Javier Gonzalez-Lagunas, DDS, MD, Casanova 101, Principal, Barcelona, 8011, Spain (Juan Antonio Hueto, MD; Eduard Serrano, MD; Guillermo Raspall, MD, DDS; Pere Huguet, MD) Introduction: Bilateral tumors of the parotid gland are infrequent and range from 0.5% to 3.5% of all parotid tumors. We present the findings of a survey of patients affected by neoplasms of the parotid gland. Our diagnostic protocol and a rationale for management of bilateral tumors of the parotid will be introduced. Material and Methods: We present a retrospective study of 215 consecutive tumors of the parotid gland treated in the Department of Oral and Maxillofacial Surgery of Hospital Vall de Hebron, between January 1989 and December 1998. Surgery was performed in 207 cases (96.3%): superficial parotidectomy in 182 cases, total parotidectomy in 5 cases, and an associated neck dissection in 20 patients. Results: In the series, 6 cases of bilaterality were observed (2.8%). Sex distribution was M:F-4:2, with an age range of 54 to 79 years (65.8 years). Fifty percent of tumors corresponded to Warthin’s tumor, 33% to benign mixed tumor, and 16% to oncocytoma. No case of bilateral malignant tumor was observed. Discussion: Previous authors have discussed the epidemiology of bilateral major salivary gland tumors, and their results are remarkably similar: low incidence (0.5% to 3.5%) and clear predominance of Warthin’s tumor, followed by mixed tumor and acinic cell carcinoma. Different histologic patterns in the same patient are rare. Diagnostic workup of parotid neoplasm includes CT or MRI imaging plus a fine-needle aspiration cytology. This procedure is performed in all tumors of the major saliAAOMS • 2001

Scientific Poster Session vary glands. A high sensibility and specificity of the technique have already been presented. With a diagnosis of benign versus malignant neoplasm, surgical planning may include superficial parotidectomy, total parotidectomy, and any of those procedures associated with a neck dissection. In bilateral tumors, our attitude is as follows: 1) bilateral benign tumors of similar size indicate simultaneous bilateral parotidectomy; 2) bilateral benign tumors of different sizes, or deep lobe affectation indicate 2 surgeries, treating the difficult side first; and 3) synchronic malignant and benign tumors indicate treating the malignant side first. Controversy exists on the need of imaging procedures and cytology when there is a solid clinical suspicion of benignity. Also, there is no agreement on the sequence of surgery in bilateral tumors. Conclusions: We describe 6 cases of bilateral parotid gland tumors, and we present our diagnostic protocol that allows the surgeon to undertake surgery with a clear view of size, location, and likely behavior of the lesion. References Turnbull AD, Frazell DL: Multiple tumors of the major salivary glands. Am J Surg 118:787, 1969 Byrne MN, Spector JG: Parotid masses: Evaluation, analysis and current management. Laryngoscope 98:99, 1988

POSTER 7 Peripheral Assessment of AnxietyInduced Vasoconstriction by Laser Doppler Flowmetry from Two Different Injections Elie Ferneini, MHS, University of Connecticut School of Dental Medicine, 33 Old Foxon Rd, Bldg 276 #33, East Haven, CT 06512 (Jeffrey Bennett, DDS; Cortland Caldemeyer, DDS; Moniek Vazquez, RN; Thomas Halaszynski, DMD, MD) Introduction: Claiming fear of intraoral injections, patients may choose intravenous (IV) sedation. Frequently, subcutaneous (SC) local anesthesia will be administered to reduce the discomfort associated with IV insertion. The purpose of this investigation was to assess potential cardiovascular changes associated with an intraoral injection compared with an SC injection of local anesthesia as detected by laser Doppler flowmetry. The finger laser Doppler flowmetry is highly sensitive at detecting microcirculatory changes. These changes may not be detected by blood pressure (BP) or heart rate (HR) measurements. Methods: Seventeen healthy volunteers (ASA I and II) were monitored with a noninvasive blood pressure cuff (brachial), laser Doppler flowmeter probe (placed on the palmar surface of the index finger of the arm oppoAAOMS • 2001

site the blood pressure cuff), pulse oximeter, and a 12-lead electrocardiogram. Baseline values were obtained prior to notifying each subject of the impending intraoral or forearm subcutaneous injection of local anesthetic. Mepivacaine 3% was injected for both intraoral and subcutaneous injections; each following a random order and the second injection (either intraoral or SC) performed subsequent to return to baseline values of all measured parameters. Each subject rated his or her anxiety levels and pain scores prior to and during each injection. The resulting measurements were tabulated, compared, and analyzed using paired t-tests (P ⬍ .05 was considered statistically significant). Results: Each volunteer rated their degree of anxiety (mean score of 3.4 for the intraoral and 2.8 for the SC injection on a scale of 0-10) higher during the anticipation period prior to the intraoral injection, but rated their pain scores (mean score of 1.2 for the intraoral and 2.8 for the SC on a scale of 0-10) higher following the SC injection. Finger flux declined in response to the anticipation of an injection (60.8% of baseline for SC and 67.5% of baseline for intraoral injection, P ⬍ .05 for both injections) and returned to baseline values at 4 to 5 minutes following intraoral and SC injections. There was no statistical difference between the changes for either the SC or the intraoral injection. Conclusion: Although patients in this study anticipated higher anxiety with an intraoral injection, their pain scores were higher for SC injections. Laser Doppler readings of the finger decreased during periods of anxiety (anticipation of an injection) demonstrating greater than a 30% change when compared with baseline values. The detection of vasoconstrictive changes in digital blood vessels may be reflective of alterations in perfusion to the myocardium. These peripheral microcirculatory changes were previously reported after an intraoral injection despite minimal to no change in HR or BP. Despite increased anxiety associated with anticipation of intraoral injections, changes that represent an impact of regional vasoconstrictive sequelae (for example, myocardial injury) occurred after both types of injections. To reduce patient anxiety and stress, behavioral and/or pharmacologic management and proper monitoring prior to any dental intervention may play a key role. References Silverman DG, Jotkowitz AB, Gutter V, et al: Regional vs. systemic responses to mental stress: A potential mechanism for non-demandrelated ischemia. Microvascular Res 51:396, 1996 Low PA, Neumann C, Dyck PJ, et al: Evaluation of skin vasomotor reflexes by using laser Doppler velocimetry. Mayo Clin Proc 58:583, 1983 Femeini EM, Bennett J, Silverman DG, et al: Hemodynamic assessment of local anesthetic administration with and without vasoconstrictor by laser Doppler flowmetery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod (accepted for publication)

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Scientific Poster Session

POSTER 8

POSTER 9

Experimental Study Concerning the Osteosynthetic Methods on the Anterior Maxillary Osteotomy

Thickening Change of the Disc in Patients With Symptomatic Temporomandibular Joint Hypermobility

Syuichi Fukunaga, DDS, DDSc, 5-4-16 Honchyou, ShikiCity, Saitama, 353-0004, Japan (Jun Shimada, DDS, DDSc; Hiromasa Tanaka, DDS; Yoshiro Yamamoto, DDS, PhD)

Xiaojiang Yang, DDS, Department of Oral and Maxillofacial Surgery, Institute of Dentistry, Oulu University Box 5281, 90014 Oulu, Finland (Hannu Pernu, DDS, MD; Juhani Pyhtinen, MD, PhD; Kyosti S. Oikarinen, DDS, PhD; Aune M. Raustia, DDS, PhD)

We conducted dynamic experiments with dried human cranial bones to evaluate the stability of fixation with all kinds of osteosynthetic materials following anterior maxillary osteotomy. The types of fixation investigated in the experiments were the resin base for the palate only, the L-type absorbable miniplate only, the L-type miniplate made of titanium only, the combination of L-type absorbable miniplate and the resin base for the palate, the combination of the L-type miniplate made of titanium and the resin base for the palate, the T-type absorbable miniplate only, the T-type miniplate made of titanium only, the combination of T-type absorbable miniplate and the resin base for the palate, and the combination of the T-type miniplate made of titanium and the resin base for the palate. The following conclusions were obtained: 1. The absorbable miniplates better resisted the separation of osteosynthesis that occurred in the direction vertical to the direction of load and the bending movement that occurred at the site of osteosynthesis against the forces received from ahead, when they were compared with the miniplates made of titanium. 2. The miniplates of the L-type better resisted the separation of osteosynthesis that occurred in the direction vertical to the direction of load, the bending movement that occurred at the site of osteosynthesis against the forces received from ahead, and the twist that occurred at the site of osteosynthesis against the occlusal forces, when they were compared with the miniplates of the T-type. 3. The type of fixation of miniplate only should be combined with the resin base for the palate. 4. The resin base for the palate is a fixation that should be used positively. 5. The best fixation was the one obtained by the combination of the L-type absorbable miniplate and the resin base for the palate. References Tachikawa N, Sugiyama Y, Miki T, et al: Drawn poly-L-lactide plates and screws for oral and maxillofacial surgery. Asian J Oral Maxillofac Surg 8:1, 1996 Harada K, Enomoto S: Stability after surgical correction of mandibular prognathism using the sagittal split ramus osteotomy and fixation with Poly-L-Lactic Acid (PLLA) screws. J Oral Maxillofac Surg 55:464, 1997

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Introduction: Pathologic changes of the temporomandibular joint (TMJ) disc in magnetic resonance image (MRI) have been found in patients with temporomandibular joint disorder (TMD). Temporomandibular joint hypermobility (TMJH) may bring out the symptoms of TMD, ie, painful symptoms, clicking and/or occasional locking. However, pathologic changes of the disc have not been reported in MRI in patients with symptomatic TMJH. Purpose of the Study: The aim of this study was to investigate the pathologic changes of the TMJ disc by MRI in patients with symptomatic TMJH and to analyze the correlation between these changes and the clinical symptoms of the patients. Materials and Methods: For this retrospective study, bilateral or unilateral TMJH was demonstrated in 74 patients in maximal mouth open MR images (127 TMJs; 56 females; 18 males; range, 15 to 72 years; mean, 40.7 years). The cases were selected from a total of 312 patients examined by MRI because of TMJ problems (1991 to 2001). MRI for TMJ in oblique sagittal, direct sagittal, and coronal projections was used in T1-, T2weighted, and Proton Density images for mouth closed and maximal mouth open positions. Disc morphologic changes were observed in MRI. The clinical symptoms recorded in these patients were clicking, progressing or constant pain in the TMJ, facial pain, and palpation and/or provocation pain in the lateral pterygoid muscle (LPM) and other masticatory muscles. Statistical analysis of the data was performed using Fisher’s exact test in SPSS 9.0. Results: The most typical MRI findings of the TMJ disc were disc thickening, disc folding, and disc thinning. Disc thickening (47 TMJs, 37.0%) was significantly more often observed than disc folding deformity (12 TMJs, 9.4%) and disc thinning (10 TMJs, 7.9%) in the patients with symptomatic TMJH. In 62 TMJs (48.8%, 62/127) a normal disc was seen in MRI. The results also showed that disc-thickening change was significantly associated with pain symptoms in the TMJ region. Normal disc morphology in MRI was found significantly more often in the cases with pain symptoms of the LPM and other masticatory muscles (P ⬍ .001). Conclusion: Disc thickening was found to be an important pathologic change of the disc in the patients AAOMS • 2001

Scientific Poster Session with symptomatic TMJ hypermobility and presented a close association with the pain symptom in TMJ. The patients with normal disc morphology in MRI also had painful symptoms, which seemed to be mainly related to masticatory muscle pain. References Landes C, Walendzik H, Klein C: Sonography of the temporomandibular joint from 60 examinations and comparison with MRI and axiography. J Maxillofac Surg 28:352, 2000 Katzberg RW, Keith DA, Guralnick WC, et al: Correlation of condylar mobility and arthrotomography in patients with internal derangements of the temporomandibular joint. Oral Surg Oral Med Oral Pathol 54: 622, 1982 Funding Source: University of Oulu.

reduction and the control animals (n ⫽ 7) had a 38% ⫾ 19% reduction in latency as compared with baseline behavior. By 24 hours post-carra, paw withdrawal latencies for all the animals had returned to baseline readings. Conclusion: Propofol has no effect on postsurgical hyperalgesia as measured by paw withdrawal latency in the carrageenan-induced inflammation model of hyperalgesia in rats. References Goto T, Marota J, Crosby G: Pentobarbitone, but not propofol, produces pre-emptive analgesia in the rat formalin model. Br J Anesth 72:662, 1994 Pastuovic M, Cohen M, Burton R: Propofol: An alternative general anesthetic for outpatient oral surgery. J Oral Maxillofac Surg 54:943, 1996 Funding Source: NIH/NIDCR R01 DE11277.

POSTER 10 Propofol Does Not Diminish Hyperalgesia in a Rat Model of Inflammation Anthony S. Leong, BS, 18-179 Moos Tower, 515 Delaware St SE, Minneapolis, MN 55455 (Catherine Harding-Rose, BS; Walter R. Bowles, DDS; James Q. Swift, DDS) Purpose: Propofol is an intravenous anesthetic used in outpatient oral surgical procedures. It is a unique anesthetic agent that belongs to the class of sterically hindered phenols with the benefits of rapid recovery and low incidence of adverse events (Pastuovic et al, 1996). Anecdotal reports indicated that some oral surgery patients seemed to report a decrease in postoperative discomfort compared with other intravenous anesthetics. To study the effects of propofol on postsurgical analgesia, a rat model of pain and inflammation was employed. Methods: Male Sprague Dawley rats, approximately 125 to 150 g, were anesthetized with propofol via intravenous tail vein injections for 15 to 30 minutes at a dose of 10 mg/kg. This corresponds to the middle dose of propofol used in a similar study in which propofol was compared with sodium pentobarbital (Goto et al, 1994). While sedated, inflammation was induced with carrageenan in the right hind paw. Hyperalgesia was assessed by measuring paw withdrawal latency (PWL) to a radiant beam of light directed at the plantar surface of each hind paw. Each paw was measured twice. The animals were tested at 3, 6, 24, and 48 hours after carrageenan injection. Each paw was compared with the contralateral paw as well as uninflamed control animals. Results: There were no differences between the propofol-treated animals and the control animals at any time point (P ⫽ NS). All of the animals showed maximal reduction in paw withdrawal latency 3 hours post-carra. The propofol group (n ⫽ 12) showed a 45% ⫾ 8.7% AAOMS • 2001

POSTER 11 Immediate Ridge Preservation With Anorganic Bovine Bone Following Tooth Extraction Matthew E. Dudziak, DDS, LSU School of Dentistry, Department of Oral & Maxillofacial Surgery, 1100 Florida Ave, New Orleans, LA 70119 (Michael S. Block, DMD) Following tooth extraction it is common for labial bone to resorb in an unpredictable manner, resulting in loss of a portion of the cortical bone. This loss of bone may limit ideal implant placement. Depending on the etiology leading to tooth extraction, such as severe periodontal disease or chronic bone loss from tooth fracture, bone loss may be significant, resulting in less than ideal bone available for implant placement. In an effort to preserve and create sufficient bone for implant placement following tooth extraction, we have utilized anorganic bovine bone as a graft material. Aim: This abstract reports a consecutive series of 17 patients, all of whom were treated in a similar manner. Methods: Each patient had teeth extracted secondary to caries, advanced periodontal disease, or tooth fracture. At the time of tooth extraction, the soft tissue remnants were removed with a curette. The extraction sockets were filled with graft material, with labial bone height re-established with additional graft material. For anterior maxillary sites, a collagen membrane/plug was used to maintain the graft in the socket. For posterior sites, the periosteum was scored and the extraction site closed primarily. After 12 to 16 weeks for healing, implants were placed and restored 5 months later. Results: Seventeen patients had 22 sites treated. Four sites were in the anterior maxilla. Ten sites were in the posterior maxilla. No patients had anterior mandibular 103

Scientific Poster Session sites treated. Eight sites were in the posterior mandible. One maxillary canine site required additional grafting at implant placement. One patient had maxillary molar sites grafted but required sinus grafting for implant placement. The remaining 19 sites did not require additional grafting at the time of implant placement, with sufficient site preservation for ideal implant placement. To date, all implants have integrated without lack of integration. Conclusions: The use of anorganic bovine bone has potential, as shown in this limited series of patients, to provide sufficient ridge preservation for implant therapy. References Sclar AG: Preserving alveolar ridge anatomy following tooth removal in conjunction with immediate implant placement, the Bio-Col technique. Atlas Oral Maxillofac Surg Clin 7:39, 1999 Berglundh T, Linde J: Healing around implants placed in bone defects treated with Bio-Oss: An experimental study in the dog. Clin Oral Implants Res 8:117, 1997

POSTER 12 Regulation of Capsaicin Sensitivity in the Extraction Site Catherine Harding-Rose, BS, University of Minnesota School of Dentistry, 18-179 Moos Tower, 515 Delaware St SE, Minneapolis, MN 55455 (Walter R. Bowles, DDS, MS; James Q. Swift, DDS; Toni A. Bowles, RN; Kenneth M. Hargreaves, DDS, PhD) Capsaicin is an excitatory agent used extensively in neurochemical and biological research. This agent activates a subpopulation of polymodal nociceptors (C and A delta nociceptors) via the capsaicin receptor (VR-1), and activation of intradermal primary afferent fibers sensitive to capsaicin produces reports of an intense burning pain (Simone et al, 1989). Capsaicin stimulates the release of neuropeptides and is thought to deplete neuropeptide stores in its role as a topical analgesic agent. Regulation of capsaicin sensitivity may occur through 2 different mechanisms—a pharmacologic desensitization (tachyphylaxis) or a functional desensitization (inactivation). Tachyphylaxis occurs when prolonged or repeated exposure to capsaicin occurs, producing a decreased response to capsaicin while inactivation produces a decreased response to other stimuli. The purpose of our experiment was to evaluate regulation of capsaicin sensitivity in primary afferent fibers of third molar extraction sites using the release of immunoreactive substance P (iSP) as a marker. Patients with indication for surgical extraction of mandibular third molars who provided informed consent had their impacted mandibular third molars removed under local anesthesia and conscious sedation techniques. Samples were collected through microdialysis probes implanted into the surgical wounds. Capsaicin (30 micromolar) or vehicle 104

was administered to the extraction site for 30 minutes (short-term) or 240 minutes (long-term). Fractions were collected every 30 minutes and iSP was measured using a previously validated radioimmunoassay (RIA). Patients who received a short-term capsaicin bolus showed an almost 3-fold increase in iSP release 90 minutes postcapsaicin as compared with patients receiving vehicle (14.33 ⫾ 6.33 fmol vs 5.80 ⫾ 0.61 fmol; P ⬍ .005). On the other hand, patients who experienced long-term capsaicin exposure showed a 45% decrease in iSP release at this time point as compared with vehicle patients (3.17 ⫾ 0.41 fmol vs 5.80 ⫾ 0.61 fmol; P ⫽ NS). Collectively, these data suggest that pharmacologic desensitization of capsaicin-sensitive fibers in the extraction site occurs and may be a potential site for novel therapeutic agents in the management of dental pain. References Simone DA, Baumann TK, LaMotte RH: Dose-dependent pain and mechanical hyperalgesia in humans after intradermal injection of capsaicin. Pain 38:99, 1989 Dray A, Bettaney J, Forster P: Capsaicin desensitization of peripheral nociceptive fibers does not impair sensitivity to other noxious stimuli. Neurosci Letts 99:50, 1989 Funding Source: NIH/NIDCR R01 DE11277.

POSTER 13 Calcium Phosphate Bone Cement as a Method for Grafting Large Mandibular Defects Lee Carrasco, DDS, MD, 5500 Wissahickon Ave, #702 A, Philadelphia, PA 19144 (Helen Giannakopoulos, DMD, MD; David Stanton, DMD, MD) Carbonated calcium phosphate bone cement (CPC) was utilized as a graft material in an 11-year-old boy after the removal of a massive right hemimandibular odontogenic keratocyst to encourage early postoperative bone regeneration. To our knowledge this is the first reported case of CPC used to graft a large mandibular lesion. The patient underwent an excisional biopsy of a large lesion that extended from the right mandibular coronoid to the right mandibular parasymphysis. The parents were unwilling to subject the child to standard autologous or allogenic bone grafting techniques, for fear of postsurgical morbidity and disease transmission. Therefore, the residual bony defect was grafted with CPC. Over the next 24 months, the patient was followed up with serial panoramic radiographs to evaluate new bone formation. The bone cement was rapidly resorbed and replaced with new bone. It was concluded that CPC could be used to prevent soft tissue ingrowth and encourage bone formation, thus gaining earlier stability to large mandibular bony defects. Although CPC is not currently apAAOMS • 2001

Scientific Poster Session proved for such uses, it serves as an excellent alternative when patients and/or parents are unwilling to submit to autogenous or allogenic bone grafts. References Schmitz J, Hollinger J, Milam S: Reconstruction of bone using calcium phosphate bone cements: A critical review. J Oral Maxillofac Surg 57:1122, 1999 Constantz B, Ison IC, Fulmer MT, et al: Skeletal repair by in situ formation of the mineral phase of bone. Science 267:1796, 1995

References Martı´nez-Pe´rez D, Varela-Morales M: Conservative treatment of dentigerous cyst in children: A report of 4 cases. J Oral Maxillofac Surg 59:331, 2001 Clauser C, Zuccati G, Barone R, et al: Simplified surgical orthodontic treatment of a dentigerous cyst. J Clin Orthod 28:103, 1994

POSTER 15 Oral Clindamycin for the Treatment of Cervicofacial Actinomycosis

POSTER 14 Surgical-Orthodontic Management of Retained Teeth Associated With Dentigerous Cyst in a Venezuelan Children Population Sol C. Del Valle, DDS, Centro Integral #105, Santa Rosa De Lima, 1061 Caracas, Venezuela (Cesar A. Guerrero, DDS; Bernhard Von Einem, DDS; Alejandra Rojas, DDS; Helen Rivera, DDS, MS) Introduction: A common cause of delay in the eruption of the permanent dentition is the presence of a dentigerous cyst that interferes with the normal process. Regezi and Sciubba, in 1993, described the dentigerous cyst as a frequent odontogenic cyst associated with the crown of an unerupted tooth. A different modality of treatment includes the maintenance of the permanent tooth at the time of surgery. Some cases postoperatively will need an orthodontic appliance to help the eruption. Objective: The purpose of this clinical trial is to prove that the permanent tooth associated with a dentigerous cyst can be left if the lesion does not involve the whole tooth and it is of small size. Materials and Method: Six Venezuelan children between 7 and 12 years of age underwent surgery (excisional biopsy) to confirm the presence of a dentigerous cyst and in all of the cases the permanent teeth involved were not removed. A close radiographic follow-up was done at 3 months, 6 months, and 14 months after surgery. Clinical follow-up also included periodical visits to the oral surgeon and the orthodontist. Results: Each patient presented with normal eruption of permanent teeth after 2 years and 3 months of followup. There is no recurrence of the pathologic lesion and no extraction was needed of the associated permanent teeth related to the dentigerous cyst. All the patients have their complete permanent dentition. Conclusions: This clinical trial emphasizes the importance of an interdisciplinary team in the management of permanent teeth associated with the dentigerous cyst. It is also relevant that this approach includes a conservative surgery with or without the necessity of orthodontic treatment. AAOMS • 2001

Carolina Bonilla, DDS, Centro Integral, #105 Santa Rosa De Lima, 1061 Caracas, Venezuela (Sol C. Del Valle, DDS; Cesar A. Guerrero, DDS; Raul Garcia-Arocha, DDS) Introduction: Cervicofacial actinomycosis is a chronic bacterial disease commonly caused by Actinomyces israelii, an anaerobic gram-positive bacterium. This saprophytic bacterium is a normal inhabitant of the oral cavity. The infection usually appears after trauma, surgery, or previous infection. Tooth extraction, periodontal surgery, and oral infections predispose to the development of this condition. Actinomycosis typically presents as a swelling of the mandible that may simulate an abscess. The lesion is indurated, cold to touch, and the draining pus may contain small yellow granules known as “sulfur granules,” without a fetid smell. This lesion usually recurs. Objective: The aim of this clinical study was to prove the oral clindamycin effect for the treatment of cervicofacial actinomycosis. Materials and Method: Six patients presenting with cervicofacial actinomycosis were treated with 300 mgrs of oral clindamycin every 6 hours for 21 days and eliminating the etiological dental factor. The patients were followed for 6 months after treatment. Results: The swelling of the mandible rapidly disappeared. Approximately 4 days after taking this antibiotic, the patients’ edema progressively resolved. There was no recurrence of the lesion after treatment. Conclusions: Oral bactericidal clindamycin is effective in anaerobic infections. This antibiotic is a viable alternative for the conclusive treatment of cervicofacial actinomycosis. In our trial, there was no recurrence. References Martin MV: Antibiotic treatment of cervicofacial actinomycosis for patients allergic to penicillin: A clinical and in vitro study. Br J Oral Maxillofac Surg 23:428, 1985 Osaki W, Abubaker O, Sotereano GC, et al: Cervicofacial actinomycosis following sagittal splint ramus osteotomy: A case report. J Oral Maxillofac Surg 50:649, 1992

Funding Source: Oral Surgery Postgraduate Program, Dental School, Universidad Central de Venezuela.

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POSTER 16 A Study of Patients With Occupational Maxillofacial Injury Shun-ichi Meguri, Department of Oral and Maxillofacial Surgery, Hamamatsu Rosai Hospital, 25 Shogencho, Hamamatsu, Shizuoka, 430-8525, Japan (Yasuo Nakajima) Disturbances existing in patients with occupational maxillofacial injury were statistically analyzed to examine trends and develop countermeasures. Analysis of age revealed that 13 of 36 occupational injury patients were in their 50s and were the largest group. For the difference of sex, there were 29 men and 7 women. For the department of group medicine, neurosurgery, orthopedic surgery, and ophthalmology departments were the most common in that order. For the cause of accident, traffic accidents accounted for 32 of 36 cases. For the diagnosis, name of injury, fracture of the mandible, injury of teeth, and fracture of maxilla were the most common in that order. For the existence and class of disturbances, disturbances of masticatory and speech function, disturbances of teeth, and disturbances of complexion were the most common in that order. Many patients with occupational maxillofacial injury are treated by group medicine. Thus, there is a tendency to focus on other severe regions. Since the main part of oral and maxillofacial dysfunction concerns eating disturbances, treatment and care to improve the quality of life are important for those with occupational maxillofacial injury.

POSTER 17 Efficacy of High Condylectomy for Management of Condylar Hyperplasia Patricia Garcia-Morales, DDS, MSD, 3409 Worth St, Suite #400, Dallas, TX, 75246 (Larry M. Wolford, DMD; Pushkar Mehra, BDS, DMD; Oscar Reiche-Fischel, DDS; Carlos A. Morales-Ryan, DDS, MSD) Purpose: The purpose of this study was to compare the treatment outcome and long-term follow-up stability between patients diagnosed with active condylar hyperplasia (CH) and treated by 2 different surgical methods. Patients and Methods: Fifty-four patients (32 females, 22 males) met the criteria for inclusion in the study for active type 1 CH. Group 1 (n ⫽ 12) was treated with orthognathic surgery only, while group 2 (n ⫽ 42) had high condylectomy, articular disc repositioning, and orthognathic surgery. All patients underwent standardized clinical and radiographic examination at initial consulta106

tion (T1), immediately presurgical (T2), immediately postsurgical (T3), and longest follow-up (T4). Objective evaluation of TMJ function included maximum incisal opening (MIO), and lateral excursions (LE). Subjective evaluations were performed in group 2 for TMJ pain, jaw function, and diet. Lateral cephalometric radiographs were evaluated for pre- and postsurgical mandibular growth using: 1) Frankfort horizontal-NB angle; 2) condylion-pogonion length; and 3) condylion-point B length. Student’s t test was utilized to analyze the data at P ⬍ .01 and P ⬍ .05 value levels. Results: In group 1 (n ⫽ 12) the average age at surgery was 17.5 years, average presurgical follow-up was 12.5 months, and the average postsurgical follow-up was 5.6 years. In group 2 (n ⫽ 42) the average age at surgery was 16.7 years, average presurgical follow-up was 12.3 months, and the average postsurgical follow-up was 5.3 years. There was no statistically significant difference (P ⬎ .05) in the 2 groups for MIO, LE, and subjective jaw function presurgically. There was a statistically significant difference between both groups (P ⬍ .05) for mandibular growth with group 2 showing more active presurgical growth. At long-term follow-up, no differences were found in LE and subjective jaw function. There was a statistically significant difference between the 2 groups in MIO (P ⬍ .01) showing more increase in group 2. There was a statistically significant difference between both groups (P ⬍ .05) regarding long-term cephalometric stability with group 2 being more stable at long-term follow-up. All of the patients in the group 1 grew back into skeletal and occlusal Class III relationships and required secondary intervention. Only 1 patient in group 2 required secondary surgery, and that involved maxillary surgery for correction of postsurgical transverse maxillary relapse; the mandible, however, was stable at longterm follow-up. Conclusions: Mandibular condylar hyperplasia is a unilateral or bilateral pathologic condition that causes overdevelopment of the mandible, often creating significant functional and aesthetic deformities. The results of this study showed patients with active CH treated with high condylectomy, articular disc repositioning, and orthognathic surgery have stable, predictable outcomes as compared to those treated with orthognathic surgery only. The high condylectomy effectively arrests disproportionate mandibular growth while maintaining normal jaw function.

References Hampf G, Tasanen A, Nordling S: Surgery in mandibular condylar hyperplasia. J Maxillofac Surg 13:74, 1985 Fuselier JC, Freitas RZ, Wolford LM: Mandibular setback procedures with sagittal split osteotomies in non-growing patients. J Oral Maxillofac Surg 57:94, 1999

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POSTER 18 Superselective Endovascular Treatment of Vascular Lesions in the Head and Neck Andre´s F. Herrera, DDS, 140 South Harvey Ave, #3, Oak Park, IL 60302 (Mark J. Steinberg, DDS, MD; Harish Shownkeen, MD) The head and neck region constitutes one of the most common sites for presentation of vascular lesions. These lesions are classified according to the endothelial cell behavior; the major classes are either hemangioma or congenital arteriovenous vascular malformation (AVVM). The AVVMs are further subclassified according to their flow characteristics being either a low- or high-flow lesion. In general, vascular lesions can present with a wide variety of clinical characteristics, ranging from aesthetic compromise, pain, and life-threatening hemorrhages. Multiple treatment approaches have been advocated including surgical resection, local injection of sclerosing agents, endovascular embolization, systemic therapy with immunosuppressant medications, and radiation, among others. Some of the complications associated with surgical treatment include disfiguring results, partial resection, and more seriously severe intraoperative hemorrhage. During the last 10 years, advances in interventional radiology, embolitic materials, and delivery systems have positioned endovascular treatment as an important therapeutic modality in the management of head and neck vascular lesions. In the past, larger and stiffer catheters only allowed the catheterization of large proximal feeding vessels. The embolization of the proximal vasculature was associated with development of collateral feeders, and in some situations, with avascular necrosis of noninvolved tissues and structures. This was a significant drawback due to the presence of significant aesthetic structures and sense organs in the maxillofacial region. Superselective catheterization of small diameter vessels assures a targeted delivery of embolitic and sclerosing agents to the lesion, limiting the damage to the surrounding tissues. In our institution, we have treated a total of 11 patients with head and neck vascular lesions using superselective embolization as a sole treatment or combined with surgical resection, with excellent results. There has been only a low incidence in minor intra- or postoperative complications during the past 2 years. In summary, superselective endovascular embolization offers a minimally invasive technique for the treatment of vascular lesions in the oral and maxillofacial region, and it should be considered as a fundamental therapeutic tool for their management. References Kawano K, Mizuki H, Mori H: Mandibular arteriovenous malformation treated by transvenous coil embolization: A long term follow-up

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with special reference to bone regeneration. J Oral Maxillofac Surg 59:326, 2001 Larsen PE, Peterson LJ: A systematic approach to management of high-flow vascular malformations of the mandible. J Oral Maxillofac Surg 51:62, 1993 Muto T, Kinehara M, Takahara M, et al: Therapeutic embolization of oral hemangiomas with absolute ethanol. J Oral Maxillofac Surg 48:85, 1990

POSTER 19 Intravenous Ketamine in a Deep Conscious Sedation “Cocktail” Eugene F. Roginsky, Jr, DMD, MD, Department of Oral and Maxillofacial Surgery, Kings County Hospital Center, 451 Clarkson Ave, Brooklyn, NY 11203 (Kouros Izadi, DDS, MD; Stewart K. Lazow, DDS, MD; Steven R. Izzo, DDS) The purpose of the study was to evaluate the addition of ketamine to our deep conscious sedation protocol. In 1990, Krishtalskyj et al compared a combination of diazepam/meperidine/ketamine vs diazepam/meperidine/methohexital. Blankenstein and Anderson compared midazolam/ketamine vs midazolam/methohexital. Both studies showed equal efficacy with no difference in emergence phenomena and no apnea. We propose the combined use of midazolam with fentanyl and low-dose ketamine as a safe and efficacious anesthetic “cocktail” for a deep sedation or total intravenous anesthesia (TIVA) protocol for impaction surgery. The method was a prospective clinical trial of 90 consecutive ASA class I or II patients treated at Kings County Hospital Oral And Maxillofacial Surgery clinic for extraction of an average of 2 impacted molars per case. Midazolam 0.03 mg/kg, fentanyl 0.5 ␮g/kg, ketamine 0.5 mg/kg, dexamethasone 0.1 mg/kg, and glycopyrrolate 200 mcg were given, in addition to lidocaine/1:100,000 epinephrine local anesthesia; escape dose of methohexital or propofol was provided as needed. Results: The use of ketamine in an intravenous deep conscious sedation “cocktail” made it possible in a majority of cases to decrease or eliminate the use of methohexital with its associated risks of apnea and laryngospasms. No apnea or laryngospasms occurred in the study. The use of midazolam, fentanyl, and ketamine gave a rapid induction, profound amnesia and allowed generous working times. Thirty of 90 (33%) cases required a rescue dose of methohexital or propofol. The mean dose of methohexital used was 67 mg. The mean surgical time was 18.8 minutes. The average length of time to discharge was 64 minutes. Transient tachycardia (a mean of 32.9 bpm over baseline) and hypertension (a mean of 26.2 mm Hg over baseline) were seen. Among the patients included 3 patients with asthma and 1 with sickle cell anemia. 107

Scientific Poster Session Complications: Emergence phenomenon was noted in 1 patient. Nausea was observed in 4 patients and was treated with prochlorperazine 10 mg IM. One patient was treated for intraoperative hypertension with labetolol 5 mg IV. Hypotension that responded to postural change was found in 2 of 3 patients who received a rescue dose of propofol. There was overall acceptance of this regimen with patients/staff based on recovery room exit interview. Conclusion: The use of a “cocktail” of relatively small doses of sedative/hypnotic, narcotic, and dissociative anesthetics proved to be efficacious and safe as a deep conscious sedation or total intravenous sedation (TIVA) regimen. The relatively low dosages minimized the side effects associated with each drug, at the same time taking advantage of the additive therapeutic effects. An ongoing study using the above protocol is expected to supplement 90 cases with an additional 100⫹ cases and a postoperative questionnaire for the full poster presentation. References Kryshtalskyj B, Direnfield VN, Johnson TWG: Use of low-dose ketamine hydrochloride in outpatient oral surgery. Oral Surg Oral Med Oral Pathol 69:413, 1990 Blankstein KC, Anderson JA: A double blind comparison of low dose intravenous ketamine and methohexital in adults. J Oral Maxillofac Surg 49:468, 1991

POSTER 20 TMJ Condyle Allograft Reconstruction in Rabbit Daisuke Sano, DDS, Oral and Maxillofacial Surgery, Aichi-Gakuin University 2-11, Suemori Dori, Chikusa Ku, Nagoya, 464-8651, Japan (Nobumi Ogi, DDS, PhD; Izumi Maki, DDS, PhD; Isamu Katoh, DDS, PhD; Kenichi Kurita, DDS, PhD; Hatsuhiko Maeda, DDS, PhD; Yoichiro Kameyama, DDS, PhD) The condylar process is a vital functional structure capable of stabilizing and bearing loads in the TMJ. However, absence of the TMJ condyle and disc would not be avoided in the clinical setting, because of mandibulectomy, ankylosis, and so forth. Various materials have been advocated for the use of condylar reconstruction. And yet, ideal artificial devices or biomaterials were not determined. High availability of quality tissue with heat-sterilized preservation methods from a regional bank made bone allograft accepted in Japan. The allogenic condyle seems to be advantageous in postsurgical functional adaptation. The purpose of this study was to evaluate the short-term efficacy of TMJ reconstruction with a freeze-dried or deep-frozen stored and heattreated condyle allograft. The experimental animals used were 30 Japanese white rabbits. They were divided into 108

3 different condylar reconstruction groups and underwent the following procedures. Under general anesthesia, the animals were operated on to produce a simulated unilateral condylectomy and discectomy. The grafts were anatomically replaced in optimal position and fixed with microplate and screws. In group 1 as a control, autogenous condyle replacement was carried out. Group 2 was freeze-dried condyle allograft. Group 3 was deepfrozen stored and heat-treated condyle allograft. Half the animals in each group were killed at 12 weeks and the other half were killed at 24 weeks postoperatively. The specimens were removed en bloc and processed histologically. The grafted condyle in all the groups showed incorporated healing with the recipient site of the mandible. In group 1, the shape of the autogenous condyle and eminence flattened. In Group 2, the freeze-dried condyle grossly deformed and the joint space was obliterated with fibrous tissue in some cases. The cartilage layer of the condyle showed a tendency to reduce in thickness or complete loss. Group 3 showed more similar histomorphologic features to the autogenous condyle than to the freeze-dried allograft. The deep-frozen stored and heat-treated allograft was effective in minimizing pathosis on the condylar reconstruction and expected to keep anatomical configuration and re-establish TMJ function. However, the freeze-dried condyle was biomechanically fragile and difficult in functional adaptation. References Marciani RD, Gonty AA, White DK, et al: A preliminary study of reconstruction of the monkey temporomandibular joint with autogenous tissues. J Oral Maxillofac Surg 54:191, 1995 Ito T, Sakano S, Sato K, et al: Sensitivity of osteoinductive activity of demineralized and defatted rat femur to temperature and duration of heating. Clin Orthop 316:267, 1995

POSTER 21 Maxillary Sinus Reconstruction With Autogenous Bone Graft Combined With Bovine Bone Mineral Patricia Lopez Orlando, DDS, University of Puerto Rico, Medical Sciences Campus, Oral and Maxillofacial Surgery Program, PO Box 365067, San Juan, PR 009365067 (Jose Morales Morales, DMD) Purpose: The posterior maxilla frequently presents as a challenging site for implant placement. The poor bone quality characteristic of this region, coupled with limited vertical bone height related to damage caused by periodontitis and sinus pneumatization, creates difficulties in providing a significant number of implants of sufficient length to predictably support an implant prosthesis. Creating maxillary bone for the placement of implants relies on onlay grafts, interpositional (Le Fort I), or inlay grafts, AAOMS • 2001

Scientific Poster Session which include nasal floor and sinus grafting with different materials. The aim of this study was to evaluate the results of a maxillary sinus augmentation using an iliac crest corticocancellous bone graft combined with natural porous bone mineral at the time of implant placement. Patients and Methods: Ten patients, 7 females and 3 males, ages ranging from 32 to 58 years (average, 47.3 years) with severely resorbed edentulous maxilla received bilateral sinus lift augmentation procedures. Grafts were accomplished using a crestal approach, obtaining iliac corticocancellous bone combined with porous bovine bone mineral matrix. Grafts were placed in the sinus floor using a conventional technique of lateral windows and membrane dissection. Ten core biopsy specimens were taken from grafts at the time of implant placement (8 months later). These cores were evaluated using histomorphometric analysis to yield data comparing volume fractions of bone formation. Standardized radiographic measurements of bone volume and height were obtained preoperatively, immediately postoperatively, and at the time of implant placement. Results: Bone core histomorphometric studies revealed only slight percentage variances in bone volume during 8 months of healing period with an average of 42% volume fraction of bone. Grafts sites have been found to be extremely dense when removing cores, achieving good stability for implant placement. Panoramic radiographs displayed minimal variances in bone volume when immediately postoperatively and eight months later were compared. No signs of infection was observed in any of the 10 cases. Conclusion: The study suggests that the combined use of autogenous bone graft from iliac crest with bovine bone mineral has a prolonged remodeling process, reducing the overall resorption pattern and acceptable new bone formation. Bone volume was maintained with a more stable bone graft for implant placement. Autogenous bone grafts provide phase 1 (immediate) bone production, have no antigenicity, and are extremely reliable. Alloplastic grafts provide the matrix for bone development. Because of the osteoconductive nature of these materials, it is slowly resorbed and its mineralized skeleton acts as the support of for new bone formation. However, longer follow-up is necessary and probably a prospective study with actual measurements of bony dimensions intra- and postoperatively to truly ascertain the actual resorption pattern over time. References Boyne PJ, James RA: Grafting of the maxillary sinus floor with autogenous marrow and bone. J Oral Surg 38:613, 1980 Jensen J, Krantz Simonsen E, Sindet-Pedersen S: Reconstruction of the severely resorbed maxilla with bone grafting and osseointegrated implants: A preliminary report. J Oral Maxilofac Surg 48:27, 1990 Funding Source: Oral and Maxillofacial Surgery Program.

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POSTER 22 Uncommon Presentation in Oral and Maxillofacial Complex: Metastasis of the Genitourinary Tumors Luis F. Alicea, DMD, #1 Santa Anastasia St, San Juan, PR 926 Metastatic tumors in the oral and maxillofacial region are rare, with a predilection to metastasize to the lower jaw. The most common tumors that metastasize to the jaws are breast, lung, thyroid, kidney, and prostate. Some authors reported studies that showed renal and prostate tumors as the primary ones exhibiting metastasis to the jaws, the percentages being 15% of all renal tumors and 6% of prostate tumors. Another author reported that the most common areas of metastasis in the oral cavity are the soft tissues, such as the gingiva and tongue. The major symptoms included swelling, pain, anesthesia, and loss of teeth. These tumors have also been reported to invade soft and hard tissues of the head and neck regions. We will be presenting instances of both cases, that of metastatic tumors in end-stage renal and prostate cancer patients, the physical examination, diagnostic studies, histopathologic slides, management, and the complications experienced by these patients. Finally, we will be evaluating how oral and maxillofacial surgery can aid in the diagnosis and management of this type of patient. References Mehra P, Cottrell DA, Booth DF, et al: An unusual presentation of metastatic prostate cancer. J Oral Maxillofac Surg 56:517, 1998 Quinn JH, Kreller S, Carr RF: Metastatic renal cell carcinoma to the mandible: A report of case. J Oral Surg 39:130, 1981

Funding Source: University of Puerto Rico.

POSTER 23 Paragangliomas of the Head and Neck Reynaldo Tyrone Reese, DMD, 3518 Gentry Ridge Ct, Silver Spring, MD, 20904 (Andrea Bonnick, DDS) Purpose: To expose the reader to a very rare pathologic phenomenon termed a paraganglioma, and its clinical presentation. Introduction: The paraganglioma is a very rare tumor associated with the autonomic nervous system and is derived from the neural crest. The cells of these tumors resemble tissue from the adrenal medulla and are histologically similar to pheochromocytomas. Furthermore, some of the cells can act as chemoreceptors causing elevation of blood pressure, heart rate, and diaphoresis. 109

Scientific Poster Session The tumors are collectively called paragangliomas and are named according to the location of the affected anatomic site. These tumors are classified as benign or malignant, according to their growth rates and ability to metastasize. Most paragangliomas have a very rich blood supply, derived from adjacent blood vessels. Paragangliomas of the head and neck are divided into the following 4 major categories: glomus tympanicum, glomus vagale, glomus jugulare, and the carotid body tumor. As mentioned above, the names correspond to the affected anatomic location. The glomus tympanicum occurs in the middle ear. Glomus vagale arises from the nodose ganglion associated with the vagus nerve. Glomus jugulare occurs in the jugular bulb at the jugular foramen. The carotid body tumor infiltrates the chemoreceptors at the carotid bifurcation. The carotid body tumor is the most common paraganglioma, with the glomus vagale being the second most common. Case Report: A 33-year-old patient was referred to the Howard University Hospital Department of Oral and Maxillofacial Surgery Clinic by a private dentist for evaluation and management of an arteriovenous malformation of the left mandible. The patient gave a history of facial trauma during a robbery attempt 1 year previous. The patient complained of numbness of the left lower lip, chin, and teeth. Clinically, the patient showed asymmetry of the left body of the mandible with accompanying bruit. He had no intraoral expansion and oral hygiene was fair. Medical history was significant for hypertension that was diet controlled. Arteriogram revealed a very hypervascular left mandibular mass. Our initial differential diagnosis was arteriovenous malformation versus central mandibular hemangioma. Our treatment plan included embolization of the mass, debridement of the site, and reconstruction of the defect with an autogenous bone graft. During embolization, the patient had intermittent elevations in blood pressure that persisted postoperatively. He was evaluated by the Department of Medicine and prescribed antihypertensive medication. It was noted that the patient was normotensive preoperatively. After successful embolization, the patient was taken to surgery for removal of the mass. On manipulation of the mass intraoperatively, the patient had sustained hypertension and tachycardia. Vital signs returned to normal after complete removal of the mandibular mass. Results: The specimen was submitted for histologic evaluation and was found to be a benign vascular mandibular paraganglioma. References Neville B, Damm D, Allen C, et al: Oral and Maxillofacial Pathology (ed 1). Philadelphia, PA, Saunders, 1995 Rubin E, Farber J: Essential Pathology (ed 2). Philadelphia, PA, Lippincott, 1995

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POSTER 24 Short-Term Effect of Two-Time Arthrocentesis for Moderate to Severe TMJ Dysfunction Kota Fukuta, DDS, Oral and Maxillofacial Surgery, Aichi-Gakuin University 2-11, Suemori Dori, Chikusa Ku, Nagoya, Japan (Kenichi Kurita, DDS, PhD; Nobumi Ogi, DDS, PhD; Jun-Ichi Ishimaru, DMD, DMSc) Arthrocentesis was first introduced in the field of oral and maxillofacial surgery as a simple and highly effective treatment for temporomandibular disorders with functional pain and limited mouth opening in the early 90s. Numerous reports on arthrocentesis have been published since then with favorable clinical results. However, a certain number of patients with temporomandibular disorders were refractory to arthrocentesis or other nonsurgical treatments. No previous statement referred to multiple arthrocentesis to the diseased temporomandibular joint. The aim of this study was to evaluate the effect of 2-time arthrocentesis followed by NSAID administration in moderate to severe temporomandibular joint dysfunction. Subjects were selected from a consecutive series of new TMJ disorder patients. Both panoramic radiographs and MRI were obtained on all the subjects. Patients complaining of unilateral TMJ pain and limited jaw motion were included in this study. Thirty-three patients were diagnosed as closed lock of the TMJ and 26 as osteoarthritis. The patients were clinically evaluated with pain-related measures on visual analog scales and range of mouth opening. The patients with moderate to severe TMJ dysfunction underwent arthrocentesis twice at an interval of 2 weeks followed by NSAIDs, Etodolac COX-2 inhibitor administration. The superior joint space was washed out with 200 mL of saline solution under local anesthesia. The patients were postoperatively seen every 2 weeks for 12 weeks. A questionnaire in the form of visual analog scales was completed by each patient at each follow-up visit. Objective clinical data including range of mouth opening were also collected. The NSAIDs were daily administered until the patients’ symptoms improved within follow-up of 12 weeks. Clinical outcome was judged to be successful, if functional pain decreased to slight to none on visual analog scales and mouth opening increased more than 35 mm. The patient was discharged from the therapy with substantially diminished TMJ pain and improved range of mouth opening. The overall success rate with this treatment was 60%. Pain-relieved TMJ function for the closed lock patients was restored in 64% within 12 postoperative weeks, and for the patients with osteoarthritis 54% within 12 postoperative weeks, respectively. Two-time arthrocentesis followed by NSAID administration for moderate to severe temporomandibular joint dysfuncAAOMS • 2001

Scientific Poster Session tion appears to be effective in alleviating temporomandibular joint disorders with low morbidity. References Nitzan DW, Dolwick MF, Martinez GA: Temporomandibular joint arthrocentesis: a simplified treatment for severe, limited mouth opening. J Oral Maxillofac Surg 49:1163, 1991 Dimitroulis G, Dolwick ME, Martinez A: Temporomandibular joint arthrocentesis and lavage for the treatment of closed lock: A follow-up study. Br J Oral Maxillofac Surg 33:23, 1995

POSTER 25 Ultrathin Diagnostic Arthroscopy for the Inferior Joint Space. An Experimental Study Nobumi Ogi, DDS, PhD, Oral and Maxillofacial Surgery, Aichi-Gakuin University 2-11, Suemori Dori, Chikusa Ku, Nagoya, Japan (Kenichi Kurita, DDS, PhD; Jun-Ichi Ishimaru, DMD, DMSc; Alastair N. Goss, DDSc, FRACDS, OMS, FICD) TMJ arthroscopy has become a standard for diagnosing and treating TMJ disease. Instrumentation for arthroscopy has been sophisticated and refined since its development. One of such devices is an ultrathin diagnostic arthroscope. Presurgical evaluation with TMJ diagnostic imaging is important to obtain good clinical outcome. TMJ pathosis of internal derangement and osteoarthritis is found both in the superior and inferior joint spaces. Conventional arthroscopes are too thick to scan the narrow inferior joint space and may cause iatrogenic damages of the articular condylar surface. Arthrography is the diagnostic measure of choice for the inferior joint space. However, superficial inflammatory changes including synovitis and hypervascularity are not detected with the arthrography. The purpose of this paper is to examine the application of ultrathin arthroscopy for observation of the inferior joint space of the sheep TMJ. Outer sheath and optical fiber of the ultrathin arthroscope was 1.1 mm and 0.8 mm in diameter, respectively. The animals used were adult Merino sheep with the intact or osteoarthritis-induced TMJ. Under general anesthesia, the sheep were draped in a sterile manner. The ultrathin arthroscope was introduced into the joint space through small skin incision over the TMJ. The joint space was adequately distended with normal saline irrigation to improve vision. Articular surfaces and synovial recesses of the superior and inferior joint spaces were scanned. The image of the joint space was viewed through a color TV monitor. Arthroscopic photographs were taken for documentation with a 35 mm SLR camera. The joint spaces of the intact as well as osteoarthritic TMJ were observed and recorded. Surface configuration and anatomic architecture of the intact joint were clearly recognized. It was easy to identify the anatomical landAAOMS • 2001

marks, eg, the articular surface of the condyle and eminence, disc, and anterior and posterior recesses. In the osteoarthritic TMJ, the ultrathin arthroscopic view provided various degrees of the pathologies, such as cartilage fibrillation, articular surface erosion, disc perforation, and adhesions. The outstanding ultrathin arthroscope would clinically provide valuable diagnostic information of the internal architecture with excellent optical performance. The ultrathin arthroscope is flexible enough for easy passage without risk of damages and is clear enough for observation of the inferior compartment. The technique would presurgically contribute to analyze detailed surface observation of the TMJ in a relatively noninvasive way. References Kurita K, Ogi N, Ishimaru J-I, et al: Diagnostic accuracy of the ultrathin arthroscope for temporomandibular joint osteoarthrosis: Comparison of arthroscopic and histologic findings in a sheep model. J Oral Maxillofac Surg 52:278, 1994 Goss AN, Bosanquet AG: An animal model for TMJ arthroscopy. J Oral Maxillofac Surg 47:537, 1989

POSTER 26 The Antimicrobial Effect of PRP— An In Vitro Study Holly D. Hatt, DMD, MD, National Naval Medical Center, Department of Oral and Maxillofacial Surgery, 8901 Wisconsin Ave, Bethesda, MD 20889-5066 (Jay Vandervort DDS, MD; John E. Fidler, DDS) It has been proven that platelet rich plasma increases wound healing and leads to more effective bone regeneration due to an increase in platelet concentration and the presence of 2 important growth factors—plateletderived growth factor (PDGF) and transforming growth factor beta (TGF-␤). Additionally included in this “buffy coat” of PRP are fibrinogen, clotting factors, RBCs, and WBCs. With this in mind, we intended to investigate the possible antimicrobial effect of the PRP against oral microbial flora in an in vitro study. Material and Methods: For this study, the effects of PRP on oral flora from 10 subjects were studied over a 6-month period. The subjects were from a resident/staff population and ranged in age from 26 to 45. Gingival sulcular debris was extracted and plated on 4 petri dishes—2 blood and 2 chocolate agar. In addition, a Kirby-Bauer disc containing penicillin and a gelatin disc of recently prepared autologous PRP were placed at separate poles on each plate. PRP was harvested using the Harvest Technology (Smart Prep) machine. The PRP gelatin disc was then prepared with approximately 10 mL of PRP and activated with CaCl and thrombin. The plates were incubated for 48 hours and examined macroscopically and microscopically. The Kirby-Bauer discs containing penicillin were also analyzed. 111

Scientific Poster Session Results: Of the 40 plates studied, there was consistent bacterial growth up to and over the gelatin PRP disc. This was compared to the approximate 5-mm “no growth” zone surrounding the Kirby-Bauer disc on all 40 plates. The area surrounding the gelatin PRP disc was also microscopically studied for the presence of PMNs, WBCs, and macrophages. Conclusions: This in vitro study suggests that PRP does not have an antimicrobial effect against oral microbial flora in the laboratory setting. However, PRP may inhibit bacterial growth indirectly due to increasing WBCs and chemotactic factors attracting additional cells into the area. References Marx, et al: Platelet rich plasma: Growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 58:638, 1998 Marx RL: Platelet rich plasma: A source of multiple autologous growth factors for bone grafts, in Lynch, Genco, Marx (eds): Tissue Engineering. Chicago, IL, Quintessence, 1999 Funding Source: United States Navy.

POSTER 27 Superior Analgesic Efficacy of Rofecoxib Over Codeine/Acetaminophen in Two Impacted Molar Extraction Pain Studies James R. Fricke, Jr, DDS, MSD, Austin Oral Surgery, PPD Development, 1510 W 34th St—Suite 100, Austin, TX 78703 (David J. Chang, MD; Kyle S. Christensen, DDS; Scott E. Bulloch, DDS, MS; Steven R. Bird, MS; Norman R. Bohidar, PhD; Thomas W. Dobbins, PhD; Gregory P. Geba, MD) Objective: We conducted 2 randomized, double-blind trials to investigate the efficacy and safety of the selective cyclo-oxygenase-2 inhibitor rofecoxib 50 mg, a fixed formulation of codeine with acetaminophen (cod/ac) 60/600 mg, and placebo for postoperative pain associated with the surgical extraction of impacted third molars. Methods: Patients who developed moderate or severe pain after extraction of 2 or more third molars, at least 1 of which was partially embedded in the mandibular bone, received a single dose of medication. Patients assessed pain relief at 11 prespecified time points over 24 hours after dosing. Patient global assessment of study medication was evaluated at 6 hours to determine responders (good, very good, excellent) vs non-responders (poor, fair). Two stopwatches were used to determine the time to onset of analgesia. The elapsed time between drug dose and rescue medication was recorded. Analysis: In the study, 1,390 patients were randomized to rofecoxib (n ⫽ 180), cod/ac (n ⫽ 180), or placebo 112

(n ⫽ 30); in study 2, 393 patients were randomized to rofecoxib (n ⫽ 182), cod/ac (n ⫽ 180), or placebo (n ⫽ 31). ANOVA was used for comparisons of total pain relief over 6 hours (TOPAR6) and peak pain relief. A logistic regression model was used for comparisons of patient global assessment. Kaplan-Meier time-to-event estimates with corresponding Wilcoxon statistics were used for comparisons of time to onset and time to rescue medication. Fisher’s exact test was used to compare the incidence of adverse experiences. Results: Baseline characteristics were similar among the groups for age, gender, and pain intensity. For mean TOPAR6, the primary endpoint, rofecoxib was more effective than cod/ac (study 1: 15.5 vs 10.7, P ⬍ .001; study 2: 12.4 vs 7.0, P ⬍ .001). Rofecoxib had a higher mean peak pain relief score within 6 hours postdose than cod/ac (study 1: 3.3 vs 2.7, P ⬍ .001; study 2: 2.6 vs 2.1, P ⬍ .001). A larger percentage of patients treated with rofecoxib were responders compared with cod/ac (study 1: 85.0% vs 68.2%, P ⬍ .001; study 2: 64.6% vs 36.4%, P ⬍ .001). There was no significant difference in analgesia onset between rofecoxib and cod/ac. The median time to rescue medication was longer for rofecoxib compared with cod/ac (study 1: ⬎24.0 hrs vs 6.5 hrs, P ⬍ .001; study 2: 9.6 hrs vs 2.3 hrs, P ⬍ .001). A larger proportion of patients treated with cod/ac had an adverse experience vs rofecoxib (P ⬍ .05) in both studies. The cod/ac group had a higher incidence of vomiting (study 1: 13.9% vs 5.6%, P ⬍ .05; study 2: 18.3% vs 3.8%, P ⬍ .001) and nausea (study 1: 13.9% vs 7.2%, P ⫽ .058; study 2: 25.0% vs 6.0%, P ⬍ .001). Conclusion: In these studies, rofecoxib showed consistently superior efficacy and had fewer patients with adverse experiences compared with cod/ac, providing support for the use of rofecoxib as an alternative to opioids in the treatment of postoperative dental pain. References Malmstrom K, Daniels S, Kotey P, et al: Comparison of rofecoxib and celecoxib, two cyclooxygenase-2 inhibitors, in postoperative dental pain: A randomized, placebo- and active-comparator-controlled clinical trial. Clin Ther 21:1653, 1999 Morrison BW, Christensen S, Yuan W, et al: Analgesic efficacy of the cyclooxygenase-2-specific inhibitor rofecoxib in post-dental surgery pain: A randomized, controlled trial. Clin Ther 21:943, 1999 Funding Source: Merck & Co, Inc.

POSTER 28 The Role of Thermoplast in Oral and Maxillofacial Surgery Amin Kazemi, DMD, MD, 4041 Ridge Ave, Bldg 18 Apt 406, Philadelphia, PA 19129 (D. Stanton, DMD, MD; L. Carrasco, DDS, MD; H. Giannakopoulos, DDS, MD) AAOMS • 2001

Scientific Poster Session Thermoplasts, by definition, are polymers that can be repeatedly melted and solidified without damage. Thermoplastic substances contain long thin molecules, which form tangled chains and are rigid at lower temperatures. Gradual softening of the material occurs when the glass transition temperature (Tg) is exceeded. Thermoplasts are usually used for injection molding of such items as food storage containers and toys. Thermoplasts have had extensive use in orthopedic hand surgery in creating a variety of splints for the stabilization of joints. The role of Thermoplast in oral and maxillofacial surgery has been limited to TMJ splint formation and nasal fracture splints. This study focuses on 4 cases, where Thermoplast were used to provide variety of treatments in an oral and maxillofacial surgery setting. Case #1, Thermoplast was used to provide stability and immobility for a skin graft postoperatively. Case #2, the material was used to create a palatal stent in a patient with traumatic palatal defect. Case #3, a lingual splint was formed for the reduction of a mandibular anterior alveolar fracture in a pediatric patient. Case #4, Thermoplast was used to stabilize and protect a nasal fracture postreduction. In each case the Thermoplast provided an effective and successful means of achieving stability and protection of the underlying operative/traumatic site. Its flexibility and ease of use allow for effective molding and custom construction of splints and stents in oral and maxillofacial surgery. References Rohrich RJ, Adams JR: Nasal fracture management: Minimizing secondary nasal deformities. Plast Reconst Surg 106:266, 2000 Bain GI, Mehta JA, Heptinstall RJ, et al: Dynamic external fixation for injuries of the proximal interphalangeal joint. J Bone Joint Surg Br 80:1014, 1998

POSTER 29 Evaluation of Eminectomy for the Treatment of TMJ Painful Disorders Gerson Hayashi, DDS, MSc, Rua Siqueira Campos, 30 sala 1001, Copacabana, Rio de Janeiro, 22031-070, Brazil (Glauco Lima, DDS; Cı´cero Braga, DDS; Luciano Teles, DDS) Painful disorders of the temporomandibular joint (TMJ) are responsible for an important part of these articulation pathologies, which cause extreme discomfort to the patient, as well as a dilemma to the professionals treating them. The primary treatment is carried out in a clinical level, using medicaments, oral rehabilitation, and other procedures. When the clinical treatment is not effective, most of the time surgical treatment is the chosen procedure. Several techniques have been indicated for the last years as a treatment for this condiAAOMS • 2001

tion, such as: condylectomy or condyloplasty; modified mandibular condylotomy, meniscectomy, or meniscoplasty; autogenous or allogenic grafts; and eminectomy. The latter, although it has been described for the treatment of chronic TMJ dislocation, has also been cited in world literature as one of the possible techniques for the treatment of painful TMJ disorders. The main objective of our work is to evaluate the clinical outcomes obtained from reports of patients treated surgically of painful TMJ disorders with eminectomy technique. In our study we made a retrospective analysis of 13 patients treated surgically for TMJ painful disorders, by eminectomy technique, uni- or bilateral. All patients operated had already been submitted to early clinical treatment, with no successful outcomes. A total of 23 eminectomies were accomplished with patients’ ages ranging from 19 to 56. We took into account the following factors: age, sex, race, duration of the condition, pre- and postoperative symptomatology (pain with/without clicking), postoperative follow-up period, and the degree of patients’ satisfaction by the end of treatment. All data were submitted to statistical analysis, by direct evaluation of data, central and dispersion tendencies measurements, all submitted to Student’s t test. The follow-up period ranged from 6 to 24 months. Five of 13 treated patients reported pain only (38, 46%) and 8 presented with pain and clicking (61, 53%). Eleven patients developed quite improvement of their painful state (86, 66%), nevertheless 4 still experienced clicking, but with no painful complaints (30, 76%). Only 2 patients had been continued with painful state in postoperative (15, 38%). Through direct analysis of the other data and statistical tests, we could observe the effectiveness of using eminectomy in the treatment of painful TMJ disorders. With this study we present our clinical experience with eminectomy for the treatment of painful TMJ disorders. References Quinn PD: Color Atlas of Temporomandibular Joint Surgery, St. Louis, Mosby, 1998. Eppley BL, Delfino JJ: Surgical treatment of internal derangements of the temporomandibular joint: Evaluation of two techniques. J Oral Maxillofac Surg 46:721, 1998

POSTER 30 Protocol Identifying Critical Incidents Following Mandibular Sagittal Split Osteotomy Curtis Gill, DMD, MD, University of North Carolina at Chapel Hill, Department of Oral and Maxillofacial Surgery, 115 Brauer Hall, CB 7450, Chapel Hill, NC 27599-7450 (George Blakey, DDS; Ray White, DDS, PhD; Dan Shugars, DDS, PhD, MPD) 113

Scientific Poster Session Problem: Although mandibular sagittal split osteotomy (BSSO) is frequently performed as an ambulatory procedure with planned discharge to home the day of surgery, no consensus exists identifying procedure-specific critical incidents which would dictate hospitalization on the day of surgery or during the first 48 hours after surgery. Methods: A consultant panel of 4 experienced surgeons developed a list of criteria for patients who would be eligible for discharge to home after BSSO, including an ASA I or II health status, availability of a caregiver who would monitor the patient’s progress in the first few days after surgery, and proximity to the clinical center (⬍1 hour’s driving distance). A Delphi panel composed of oral and maxillofacial surgeons (4), anesthesiologists (2), recovery room nurses (3), and laypersons (2) who previously had a family member undergo a BSSO was assembled. In the first Delphi round the panel was asked to review 2 lists developed by the consultants; critical incidents on the day of surgery which would alter the decision for discharge to home and critical incidents which would alert the designated caregiver to contact the responsible surgeon during the first 48 hours after surgery. The Delphi panel was instructed to rate each item on a 5-point Likert-type scale. The panel was also asked to suggest additional items that should be on each list. In the second Delphi round the panel was again asked to rate each item with the Likert-type scale and then to rank the items in order of importance. Results: In the first Delphi round a majority of the panel rated 6 of 10 of the critical incidents identifying the need for hospital admission on the day of surgery rather than discharge home, as “strongly agree.” The item “uncontrolled nausea/vomiting” was deemed the highest priority. The panel agreed with all 8 critical incidents that would indicate a need for the caregiver to immediately contact the responsible surgeon during the first 48 hours after surgery. The item “difficulty breathing” was rated most important. Additional items suggested by the panel were added for the subsequent Delphi round, and minor changes in wording were made to clarify all listed critical incidents. In the second Delphi round, based on the rank ordering, 3 of 14 items were deleted from the list of critical incidents suggesting admission the day of surgery. The item “patient not being alert and oriented enough to respond to questions and ambulate with assistance” was rated the most critical indication for hospital admission rather than discharge home. Three of 11 items were deleted from the list of critical incidents dictating that the designated caregiver contact the surgeon in the first 48 hours after surgery. The item “difficulty breathing” remained as the most critical indication for the caregiver to contact the responsible surgeon. In the second Delphi round the responses from the surgeons, anesthesiologists, nurses, and caregivers were quite similar. Comment: The critical incidents identified by consen114

sus by a Delphi panel of health care professionals and caregivers, all familiar with BSSO, must be tested for effectiveness in academic centers and community practice settings. In the interim, the respective lists can be quite helpful to surgeons who currently must assess the need for admission on the day of surgery and during the first few days following surgery. References Knoff SB, Van Sickels JE, Holmgreen WC: Outpatient orthognathic surgery: Criteria and a review of cases. J Oral Maxillofac Surg 49:117, 1991 Chung F: Recovery pattern and home-readiness after ambulatory surgery. Anesth Analg 80:896, 1995

POSTER 31 Use of Human Freeze-Dried Demineralized Rib for Orbital Floor Reconstruction: Clinical Results Alejandro Caribas, DMD, Cmms#352, PO Box 70344, San Juan, PR 00936-8344, Puerto Rico (Jose F. Lazaro, DDS) Numerous materials have been described in the literature for orbital reconstruction. Those most commonly used are autogenous tissues and alloplastic materials. Each material has advantages and disadvantages related to its strength, application, reactivity, infection rate, graft resorption, and surgical time. We evaluated 20 patients with traumatic defects that involved the orbital floor (2 cm approx) that were hospitalized at Maxillofacial Department of Puerto Rico Medical Center. Follow-up time was 6 to 48 months (mean, 27 months) and all patients were reconstructed using demineralized bone of ribs (Florida Tissue Bank). On follow-up, clinical signs and symptoms such a diplopia, ocular symmetry, enophthalmos, and limitation of upward gaze were recorded. Computerized tomography (CT) scanning was done in each patient in the study at 2 mm with coronal views; and differentiation on globe position and bone formation in the orbit defects was noted. We also presented our results using human freeze-dried demineralized ribs (Florida Bank of Tissue) during the last 4 years. References Choi JC, Fleming JC, Aitken PA, et al: Porous polyethylene channel implants; a modified porous polyethylene sheet implant designed for repairs of large and complex orbital wall fractures. Ophthal Plast Reconstr Surg 15:56, 1999 Yaremchuk MJ: Changing concepts in the management of secondary orbital deformities. Clin Plast Surg 19:113, 1992

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Scientific Poster Session

POSTER 32 An Investigation of the Efficacy of Platelet-Rich Plasma in Rabbit Cranial Defects: A Pilot Study Tara L. Aghaloo, DDS, MD, 1420 Princeton St #E, Santa Monica, CA 90404 (Peter Moy, DMD, Earl Freymiller, DMD, MD)

The increase in the use of platelet-rich plasma (PRP) has offered a new and potentially useful adjunct in oral and maxillofacial bone reconstructive surgery. This has led many to believe that an established body of literature supports its use. However, there is only 1 article in a refereed journal where platelet-rich plasma was added to autogenous bone to reconstruct mandibular continuity defects (Marx et al, 1998). It is known from classic molecular biology literature that important growth factors exist in platelet granules such as platelet derived growth factor (PDGF), transforming growth factor-beta (TGF-b) 1 and 2, and vascular endothelial growth factor (VEGF), which assist in both hard and soft tissue wound healing. It is assumed that this has clinical applications in bone growth. This study compares bone healing in 4 cranial defects in the rabbit grafted with autogenous bone, PRP, autogenous bone and PRP, and no graft as a control. Fifteen rabbits were included in this randomized, blind, prospective pilot study. Four equal 8-mm diameter defects were created in each rabbit cranium and immediately grafted with either autogenous bone, autogenous bone and PRP, PRP alone, or no graft as a control. Five rabbits were evaluated at 1, 2, and 4 months. The defects were evaluated by digital subtraction radiography, histology, and histomorphometric analysis. The results showed at 1 and 2 months that the control and PRP alone sites had not bridged the defect. At 4 months, the control site had bridged the defect 100% of the rabbits, but had not matured to lamellar bone. The PRP alone sites at 4 months had areas of fibrous tissue between the adjacent native bone. At 1 and 2 months, both the PRP with bone graft and bone graft alone had bridged the defect and showed woven bone in the center of the defect and mature lamellar bone adjacent to the native bone. By 4 months, both bone alone and PRP with bone graft displayed mature lamellar bone with density similar to the adjacent native bone. In conclusion, PRP with autogenous bone and autogenous bone alone appear to consolidate and remodel to form mature bone by 4 months. PRP alone may inhibit bony remodeling and maturity. More studies with larger sample sizes are necessary to evaluate bone healing and density between autogenous bone alone and in combination with PRP. AAOMS • 2001

References Marx et al: Platelet-rich plasma: Growth factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 85:638, 1998 Anitua E: Plasma rich in growth factors: Preliminary results of use in the preparation of future sites for implants. Int J Oral Maxillofac Implants 14:529, 1999 Funding Source: Department.

POSTER 33 Magnetic Resonance Imaging: Internal Derangement and Effusion in Painful Temporomandibular Joints Stefan Gerhard, DMD, MD, Department of Oral and Maxillofacial Surgery, University of Innsbruck, Maximilianstrasse 10, Innsbruck, 6020, Austria (Ansgar Rudisch, MD; Katharina Innerhofer, MD; Stefan Bertram, DMD, MD; Ru ¨ diger Emshoff, DMD, MD) Magnetic resonance (MR) imaging is currently the most accurate imaging modality for identification of disc position and effusion of the temporomandibular joint (TMJ). The purpose of this study was to investigate the relationship between the presence of TMJ pain and the MR imaging findings of internal derangement (ID) and effusion. The study comprised 41 consecutive TMJ pain patients referred to the department for treatment from January 1999 to November 2000. Criteria for including a patient were report of unilateral pain near the TMJ, with the presence of unilateral TMJ pain during palpation, function, and/or unassisted or assisted mandibular opening, and the absence of a specific clinical TMJ-related diagnosis of disc displacement with or without reduction. Bilateral sagittal and coronal MR images were obtained to establish the presence or absence of TMJ ID and/or effusion. Comparison of the TMJ side-related data showed a significant relationship between the clinical finding of TMJ pain and the MR imaging diagnoses of TMJ ID (P ⫽ .001), and TMJ effusion (P ⫽ .004). Further, there was a significant relationship between the MR imaging diagnosis of TMJ ID and TMJ effusion (P ⫽ .000). Use of the Kappa statistical test indicated poor diagnostic agreement between the presence of TMJ pain and the MR imaging diagnosis of TMJ ID (K ⫽ 0.34), TMJ effusion (K ⫽ 0.32), and TMJ “ID and effusion” (K ⫽ 0.27). The study’s findings suggest that while clinical pain is correlated to TMJ-related MR imaging findings, clinical pain, in and of itself, is not reliable for predicting the presence of TMJ ID and/or effusion. Therefore MR imaging for supplementing the clinical findings appears warranted and necessary. References Tasaki MM, Westesson PL: Temporomandibular joint: Diagnostic accuracy with sagittal and coronal MR imaging. Radiology 186:723, 1993

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Scientific Poster Session Westesson PL, Brooks SL: Temporomandibular joint: Relationship between MR evidence of effusion and the presence of pain and disk displacement. AJR Am J Roentgenol 159:559, 1992

POSTER 34 Laryngeal Mask Airway Use in General Anesthesia for Outpatient Third Molar Surgery David E. Palo, DDS, Department of Oral and Maxillofacial Surgery, Walter Reed Army Medical Center, 6900 Georgia Ave NW, Washington, DC 20307 (S. Taylor; S. Bagby) The laryngeal mask airway (LMA) is a widely accepted adjunct to oral endotracheal tube (OETT) intubation for general anesthesia. The LMA was developed and first used on a human patient in 1981. It was approved by the FDA in August 1991. It has been used successfully for short minor surgery procedures where minimal anesthetic depth is required. Objective: Does the laryngeal mask airway (LMA) reduce intraoperative and postoperative discomfort as compared with the oral endotracheal tube (OETT) for outpatient third molar surgery? What clinically meaningful differences exist between these 2 devices? Materials and Methods: This is a preliminary clinical trial, in which 14 patients were randomized equally into 1 of 2 groups, undergoing third molar removal in an outpatient general anesthesia setting from September 1, 2000, to March 1, 2000. The patients are service members between the ages of 18 and 35, ASA I (good health with no other concomitant disease), and have impacted or malposed third molars requiring surgical removal. The patients were randomized into 2 groups. Group 1 patients underwent general anesthesia using the LMA, group 2 patients underwent general anesthesia using the OETT. All patients received 10.0 mg of metoclopramide, 8.0 mg of dexamethasone prior to induction. Patients in group 1 were induced with 0.1 mg of fentanyl and 2.5 mg/kg propofol. Once induced, the flexible tube LMA was inserted and a throat pack placed. Those patients in group 2 were induced with 0.1 mg of fentanyl, 3.0 mg of tubocurare, and 2.5 mg/kg of propofol. Once airway ventilation status had been confirmed, 1.5 mg/kg succinylcholine was administered. After 1 minute these patients were intubated with the appropriately sized OETT and a throat pack placed. For both groups, general anesthesia was maintained by using nitrous oxide and a propofol infusion. Local anesthetic was administered 6 minutes prior to start, “incision,” of the case. Third molar removal was performed in the normal fashion. Upon completion of the procedure, the patients were allowed to emerge from the general anesthesia, have their throat packs removed, and were extubated accordingly when awake and responsive to verbal command. 116

They were recovered and discharged home with an escort when alert and oriented to person, place, time, and situation. Prior to discharge and 24 hrs later, patients were questioned on recall of procedure and throat discomfort. Throat discomfort is rated against the Likert scale: 0 ⫽ no sore throat, 1 ⫽ mild (sore throat when swallowing), 2 ⫽ moderate (constant sore throat), 3 ⫽ severe (constant sore throat that requires medication. Results and Conclusions: Though this study is small, no significant benefit was identified when using the LMA as compared with the OETT during removal of third molars. No statistical difference was noted between age and gender with respect to sore throat following either procedure. All 14 patients reported their throat discomfort as 1 ⫽ mild immediately following surgery and 0 ⫽ none 24 hrs later. Lengths of procedure were statistically similar between groups 1 and 2 with a mean time of 51 and 49 minutes respectively. One patient in group 1 had an unanticipated event when the LMA became dislodged at initiation of the procedure and a decision was made to switch over to an OETT. Though it is often reusable up to 35 times or more, a flexible tube LMA costs $300.00 each, whereas an OETT is disposable and costs $2.00 each. References Bennett J, et al: Use of the laryngeal mask airway in oral and maxillofacial surgery. J Oral Maxillofacial Surgery 54:1346, 1996 Brain AJ: The laryngeal mask: A new concept in airway management. Br J Anaesthesia 55:801, 1983 Note: The opinions or assertions of the authors contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. Funding Source: US Army Dental Corps.

POSTER 35 Synovial Chondromatosis of the Temporomandibular Joint Helen Giannakopoulos, DDS, MD, University of Pennsylvania Medical Center, Department of OMS, 3400 Spruce St, Philadelphia, PA 19104 (Peter D. Quinn, DMD, MD; Lee Carrasco, DDS, MD) Synovial chondromatosis is cartilaginous metaplasia within the synovium of articulating joints. Free-floating or attached cartilaginous bodies are found in the joint space upon exploration. It is a benign disease that occurs relatively frequently in larger joints, such as the elbow, wrist, hip, knee, and ankle, and it is most often monoarticular. Several etiologies have been proposed from various growth factors to chronic parafunctional overload and trauma. However, it rarely affects the temporomandibular joint. When present, this disease is usually contained within the confines of the joint space. AAOMS • 2001

Scientific Poster Session Extra-articular involvement to the surrounding temporal bone, cranium, or parotid gland has been rarely reported. Its presentation mimics features seen with internal derangement of the temporomandibular joint. The most common clinical features of synovial chondromatosis include pain, swelling, and limitation of mandibular movement. Diagnostic evaluation has included standard roentgenograms, computed tomography, magnetic resonance imaging, and arthroscopy. Diagnosis is confirmed with open biopsy. Synovial chondromatosis may recur locally, and malignant transformation has been reported in the orthopedic literature. Surgical exploration of the joint and synovectomy, alone or in combination with removal of loose bodies, is the recommended treatment. Since the first reported case of synovial chondromatosis of the temporomandibular joint in 1993, many other case reports have been presented. From 1993 to date, we present 8 of our patients with the histologic diagnosis of synovial chondromatosis. Two of these patients had resorption of the floor of the skull base with intracranial tumor invasion. We discuss presentation, diagnosis, and management of synovial chondromatosis in these 8 patients. References Karlis V, Glickman RS, Zaslow M: Synovial chondromatosis of the temporomandibular joint with intracranial extension. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 86:664, 1998 Louis PJ, West WF, Tilley MS, et al: Chondromatosis of the temporomandibular joint. J Am Dent Assoc 129:1010, 1998

POSTER 36 Immunohistochemical Characterization of Benign Lesions of the Craniofacial and Appendicular Skeleton Steven H. Young, DDS, 318 E 15th St, Apt 10E, New York, NY 10003 (Regina Landesberg, DMD, PhD; Herman Yee, MD, PhD; Roberto Garcia, MD; Robert S. Glickman, DMD) Specific Aim: Craniofacial central giant cell lesions (CGCLs) and fibrous dysplasias (FDs), although benign, often result in significant facial deformities. Although these craniofacial lesions are similar histologically to those seen in the appendicular skeleton, their clinical behavior is often different. The present treatment for these conditions is primarily surgical in nature, often resulting in significant mutilation with a high risk of recurrence. The biochemical and cellular derivation of these lesions is somewhat controversial. A recent study showed that while osteoclastic resorption in neonatal murine calvarial bone is dependent on cysteine proteinases (cathepsins B and K) and matrix metalloproteinases (MMPs), resorption in the long bones is dependent only AAOMS • 2001

on the cathepsins. These findings would suggest that pathologic entities arising in the respective tissues would also have different enzymatic profiles. However, MMPs and tissue inhibitors of MMPs have been shown to be present in appendicular central giant cell tumors (GCTs). We therefore investigated the presence of cathepsin K and MMP-9, enzymes critical for bone degradation, using immunohistochemical analysis in CGCLs, GCTs, craniofacial and appendicular FD. The biochemical/enzymatic profiles of these lesions may provide a rational basis for the use of inhibitors of the above enzymes as alternative treatments for these benign tumors. Methods: Formalin-fixed, paraffin-embedded tissues were obtained from the pathology departments at Bellevue Hospital Center/New York University and Columbia University/New York Presbyterian Hospital. Two cases of craniofacial FD, 4 cases of craniofacial CGCLs, 5 cases of appendicular FD, and 8 cases of appendicular GCTs were accessed from the pathology archives from 1993 to present. A staff pathologist confirmed each specimen’s diagnosis. Immunohistochemistry was performed according to protocol using a DAB substrate and Meyer’s hematoxylin counterstain. The optimal dilutions for antibodies to cathepsin K and MMP-9 were determined to be 1:150 and 1:15, respectively. Results of the localization studies were then analyzed and semiquantitated by image analysis. Results: The study demonstrated that there were no significant differences in the localizations of cathepsin K and MMP-9 in the osteoclasts of craniofacial CGCLs and FD versus their long bone counterparts. High levels of cathepsin K and MMP-9 were localized in the giant cells of craniofacial CGCLs and long bone GCTs, with a slightly increasing gradient of enzymes toward the resorption edge. In many of the GCGL/GCTs, a significant number of stromal cells were moderately positive. The fewer osteoclasts in the FDs were also selectively stained with respect to cathepsin K and MMP-9. Conclusions: 1) The high levels of cathepsin K and MMP-9 expressed in CGCLs would suggest that the inhibitors of these enzymes might be a potential treatment modality. 2) The enzymatic functional homogeneity of these lesions suggests that they derive from similar cellular precursors despite slightly different but overlapping clinical and histologic presentations. References Everts V, Korper W, Jansen DC, et al: Functional heterogeneity of osteoclasts: Matrix metalloproteinases participate in osteoclastic resorption of calvarial bone but not in resorption of long bone. FASEB J 13:1219, 1999 Schoedel KE, Greco MA, Stetler-Stevenson WG, et al: Expression of metalloproteinases and tissue inhibitors of metalloproteinases in giant cell tumor of the bone. Hum Pathol 27:1144, 1996

Funding Source: New York University/Bellevue Hospital Center.

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POSTER 37 Mandibular Subluxation as an Adjunct to Increase Access for Carotid Endarterectomy David B. Powers, DMD, MD, 2614 Century Ranch, San Antonio, TX 78251-4939 (Jeffery W. Armstrong, DDS) The location of the common carotid artery and the bifurcation forming the internal and external carotid arteries are readily available to the vascular surgeon, allowing treatment of atherosclerotic disease. Based on the accessibility of the carotid artery, carotid endarterectomy has become a common surgical procedure with a proven record of benefit to the patient in the treatment of atherosclerotic disease. In cases of distal carotid artery disease, high bifurcation of the common carotid, and in patients with multiple operative interventions, adequate surgical exposure can be compromised without exposing the patient to increased morbidity as seen in procedures such as mastoidectomy, mandibular osteotomy, mandibulectomy, and division of the sternocleidomastoid. Mandibular subluxation has been proven to be a simple, quick operative procedure allowing increased operative field exposure for the surgeon while subjecting the patient to minimal postoperative complications. In dentate patients, the mandible is subluxed by attaching interdental wires from the ipsilateral mandibular premolar to the contralateral maxillary premolar. In edentulous patients or patients with severe periodontal disease, a circummandibular wire can be placed around the ipsilateral mandible to the anterior nasal spine or by utilizing diagonal wiring to surgical pins, such as Steinmann pins. Subluxation and hardware removal should add no more than 15 minutes to overall anesthesia time. This technique has been used in 8 cases in our institution with an additional 1 to 2 cm of distal exposure obtained, which is consistent with previously reported data. No temporomandibular joint pain, dental injury, or cranial nerve dysfunction was noted in our patients. References Frim DM, Padwa B, et al: Mandibular subluxation as an adjunct to exposure of the distal internal carotid artery in endarterectomy surgery. Technical note. J Neurosurg 83:926, 1995 Dossa C, Shepard AD, et al: Distal internal carotid exposure: A simplified technique for temporary mandibular subluxation. J Vasc Surg 12:319-325, 1990

POSTER 38 Treatment of Midfacial Trauma Caused by Gunshot Jose O.C. Andrade, DDS, Rua Itapeva, 500 cj 1C, Bela Vista, Sao Paulo, Brazil (Luiz Carlos Manganello Souza; Maria Eduina da Silveira) 118

The wounds caused by gunshots are very common in hospitals. Many times, the face is directly affected by the bullet due to the natural exposition that this region has, as also the morbidity that comes with this kind of trauma. In the attendance of his patient, just after establishing the integrity of cardiopulmonary conditions, the injured structures should be evaluated followed by clinical and radiographic examination. In most cases these injuries are very complex with comminuted fractures and sometimes with loss of soft tissues. We treated 10 patient-victims of this kind of injury, from Nov/99 to Dec/00. All of them were victims of assault and there was just 1 shot in the face. In 4 of them we needed to wait for clinical conditions to perform the surgical treatment, and the other 6 were operated at maximum 24 hours after the trauma. In 3 cases we just removed the bullet, lined up the fractures and perform the rigid fixation with 1.5-mm and 2.0-mm system (Walter Lorenz Corp, Jacksonville, FL). In 4 cases we used autologous bone graft to substitute the loss of fragments due to comminuted fracture. In the other 3 we used titanium barriers to recompose the orbit wall. All patients had good aesthetic and functional results. We concluded that computed tomography is the examination that is indicated to evaluate the midfacial bone fractures and to perform the surgical treatment plan. The surgery performed in the first hours after trauma results in better aesthetic and functional results, due to the possibility to line up the fractures and to perform rigid fixation as to suture the soft tissue wound. Therefore this patient will be able to return soon to his routine. References Frohlich M: Gunshot injuries of the soft and bone tissue of the face. Ethiop Med J 28:99, 1990 Shepherd JP, Shapland M, Pearce NX, et al: Pattern, severity and aetiology of injuries in victims of assault. J R Soc Med 83:75, 1990 Funding Source: Hospital Israelita Albert Einstein.

POSTER 39 Diagnosis of Actinomycosis of the Cervicofacial Region via Fine Needle Aspiration Regina Saenz, DDS, 1211 S Eads St #1303, Arlington, VA 22202 (Andrea Bonnick, DDS) Actinomycosis presents either as an acute or chronic, slowly progressive, indurated, suppurative, and often painless mass. The bacterium normally has low virulence, yet becomes pathogenic once intact mucosal barriers are disrupted; the persistent infection then spreads unimpeded by traditional anatomic barriers and results in draining sinuses. The occurrence of actinomycosis is not common. Its AAOMS • 2001

Scientific Poster Session diagnosis is a challenging process. Actinomycosis has been depicted as being a “. . . masquerader and, a diagnostic and therapeutic challenge.” Hence, the practitioner is often faced with delays and errors of diagnosis. Historically, the diagnosis has been achieved via culture. The organism is anaerobic and it is very difficult to grow in culture. The culture recovery rate from active infection is only approximately 30%. Alternatively, open biopsy has also been employed. The method of cytologic aspiration, not widely used or reported, offers a minimally invasive, alternate technique for acquiring a specimen for microbiological assay. Our trials have resulted in 100% accuracy in diagnosis. In our study, patients presented with the classic signs of actinomycotic infections: chronic, peripheral indurated swelling with central abscess formation with and without extraoral draining tracts in the posterior mandibular area. All of the patients had history of prior extractions or periodontal disease. The patients had been previously treated with a regimen of oral antibiotics or extractions within the last 6 months prior to their presentation to our clinic. There were 10 patients evaluated in a period of 2 years. Fine-needle aspiration using standard techniques was performed with a 25-gauge needle. The specimens were sent for pathology evaluation, culture, and cell blocks. The results from the FNA were received within 24 hours and they were positive for actinomycosis. However, the culture results were negative for actinomycosis. The cell blocks revealed the classical sulfur granules seen as basophilic masses with a granular center and a radiating fringe of club-shaped protrusions as well as a distinctive filamentous and beaded actinomyces. This method of cytologic aspiration, which is minimally invasive, resulted in 100% accuracy in diagnosing cervicofacial actinomycosis. This allows more efficient management of patients. References Belmont et al: Atypical presentation of actinomycosis. Head Neck 21:264, 1999 Burns et al: Actinomycosis of the posterior triangle: A case report and review of literature. J Laryngol Otol 111:1082, 1997 Nagler et al: Cervicofacial actinomycosis: A diagnostic challenge. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 83:652, 1997 Pollock et al: Cervicofacial actinomycosis: Rapid diagnosis by thinneedle aspiration. Arch Otolaryngol 104:491, 1978

POSTER 40 Precise Positioning of Dental Implants Based on a 3-D Computer Program: Computer Guided Implantology Alejandra Rojas, DDS, Santa Rosa Oral and Maxillofacial Surgery Center, Santa Rosa, Caracas, 1061, Venezuela (Marianela Gonzalez, DDS, MS; Cesar A. Guerrero, DDS; Andrew Christensen) AAOMS • 2001

Introduction: The team approach based on prosthodontics, orthodontics, and surgery is essential in planning implant treatment. The importance of considering the final result at the time of planning is fundamental for a successful treatment. The use of standard templates for dental implant placement has been widely reported as a way to plan implant placement, with some limitations at the time of surgery. Another method widely used is to plan from CT scan radiographs processed in a desktop computer, with the possibility to transfer the data to the operating room. Purpose: This clinical study evaluates the final position of dental implants based on the use of a software program that allows for planning of standard, zygomaticus fixtures, or the Novum system. Materials and Methods: Eight totally edentulous (4/8) and 4 partially edentulous (4/8) patients underwent implant planning by the Guided Implantology computer technique for dental implant treatment. The protocol included a CT scan with specific requirements, including wearing a scan template. The information is then sent to the service bureau to prepare the CT data. From a set of axial CT images, a complete planning environment is created. All images obtained are cross-referenced to each other in each view, including a 3-dimensional view, which makes it easy to navigate through the series of images and find the optimal position for the placement of implants. This technique allows planning implant positioning at every possible position, locating the inferior alveolar nerve, type and volume of the bone present, and adjacent teeth. After the implants are drawn in the computer screen, custom-designed surgical guiding splints (CAD/CAM drilling templates) are designed and constructed in the 3-D model. This bone-borne splint is replicated to fit different size stainless steel guides to place the different drills required to prepare the implant site progressively and maintain the proper inclination. Results: Two patients required zygomaticus implants, 2 others needed a Novum system, and the rest were treated by standard implant techniques; to complete a total of 36 fixtures. The implants were meticulously placed with the surgical splints with 34/36 into the exact planned positioning ⫾ 1.5 mm, while the other 2 were 3 and 3.5 mm deeper than the planned position when measured in the prosthodontist model with the analogs in position. Conclusions: This novel technology helps the clinician to precisely and predictably anatomically locate the implants in the ideal position where the surgeon and prosthodontist have agreed in the preoperative planning. It is also an excellent tool to use to communicate with the team and the patient. References Worthington P, Branemark P-I: Advanced Osseointegration Surgery: Applications in the Maxillofacial Region. Quintessence Publishing, 1992

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POSTER 41

References Costa A, et al: Mini-screws as orthodontic anchorage: A preliminary report. Int J Adult Orthod Orthognath Surg 13:201, 1998 Mikako U, et al: Skeletal anchorage system for open bite correction. Am J Orthod Dentofac Orthop 115:166, 1999 Funding Source: Department of Oral and Maxillofacial Surgery, RCM P.R.

Trends in Orthodontic Anchorage System: Mini Screws Roberto J. Rodil Davila, DMD, Urb. Venus Gardens, Calle Torreon AB 34, San Juan, PR, 926, Puerto Rico (Jose Morales, DMD) Orthodontic treatment is dependent on anchorage systems that provide an area where controlled forces can be applied in order to treat a patient’s malocclusion. Anchorage systems can be classified as extraoral (headgear, face-mask, etc) and intraoral (Nace-palatal button, tooth-segment anchorage systems, etc). Both systems have limitations such as: 1) patient compliance with usage of extraoral and/or intraoral removable appliances and 2) anchorage loss as a result of implemented orthodontic mechanics. Osseointegrated appliances were first used as part of experimental orthodontics/orthopedics forces in laboratory research with monkeys. Successful forces were transferred to a monkey’s facial bones without affecting implant stability. Recently, osseointegrated implants have been used as direct or indirect anchorage systems to resist orthodontic forces applied. Osseointegrated implants have the following limitations: 1) they require an implant-osseointegration period (up to 6 months), 2) they require removal of the implant if not needed for prosthetic considerations after orthodontic treatment is finished, and 3) they are an expensive procedure. Mini-screws used as temporary implants provide the benefits of a bone-borne anchorage system that could be used in orthodontic treatment. They provide excellent anchorage to orthodontic forces (6-8 onz) without compromising intra-arch and/or inter-arch tooth stability. The dimension of the mini-screw (2.0-mm diameter, 13 to 18 mm long) allows the operator to engage the bucal and lingual cortices, which creates even more stability to resist orthodontic forces. Miniscrews can be loaded immediately, are easily retrievable after orthodontic treatment has been finished, and are fairly inexpensive. This presentation consists of 20 patients in which the mini-screw was successfully use as anchorage. The system was used for protraction of 1 and sometimes 2 permanent mandibular molars unilaterally. The low morbidity of surgery, the patient’s compliance, the good treatment results, and the ease of mini-screw retrieval make this a great intraoral extradental bone-borne anchorage system. 120

POSTER 42 Apert Syndrome Fibroblast Growth Factor Receptor-2 Mutation Downregulates Apoptosis in Osteoblasts Steven Krakora, DMD, Allegheny General Hospital, 240 East North Ave, Pittsburgh, PA 15212 (Garth Ehrilich, PhD; Chris Post, MD, PhD; Michael Cunningham, MD, PhD; David Ornitz, MD, PhD; Agnus Pollice) The biologic pathogenesis of syndromic craniosynostosis remains unknown. Apert and Crouzon syndromes are now known to be associated with mutations in either the fibroblast growth factor receptor gene family or the TWIST genes. In this study, we propose that apoptosis is a critical step in the pathogenesis of syndromic craniosynostosis. We confirm that a mutation in FGFR-2 results in the reduction of osteoblast apoptosis, which is a proposed mechanism for premature suture fusion in syndromic craniosynostosis. Calvarial bone was harvested from 21-day-old fetal rabbits. The explant method was used to develop cell lines, which were stained for alkaline phosphatase to ensure osteoblast lineage. The fetal osteoblasts were transfected with the Apert mutated FGFR2 DNA by electroporation. The apoptotic rate was determined using flow cytometric techniques after labeling with annexin V and propidium iodide. Flow cytometry analysis yielded 4 distinct cell populations: viable cells, early apoptosis, late apoptosis, and necrotic cells. The cells transfected with the Apert mutation had lower apoptotic rates compared with controls. Apert mutation versus control, respectively; viable cells, 49.2%/15.9%, early apoptotic, 37.1%/15.0%, late apoptotic, 9.0%/48.8%, and necrotic cells, 4.7%/20.3%. The Apert FGFR-2 mutation downregulates apoptosis in osteoblasts and may have a significant role in the pathogenesis of craniosynostosis. References Cohen M: Sutural biology and the correlates of craniosynostosis. Am J Med Genet 47:581, 1993 Dry G, Yasinskaya Y, Williams J, et al: Inhibition of apoptosis: A potential mechanism for syndromic craniosynostosis. J Plast Reconstr Surg 107:425, 2001 Funding Source: NIDCR R01 20 preliminary study.

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Scientific Poster Session

POSTER 43 The Use of Autologous Fat Grafts in Temporomandibular Joint Reconstruction Carlos A. Morales-Ryan, DDS, MSD, 3409 Worth St, Suite #400, Dallas, TX 75246 (Larry M. Wolford, DMD)

MIO (mm) Group 1 2

Purpose: To evaluate the efficacy of autologous fat grafts to the temporomandibular joint simultaneously with the total joint prosthetic replacement in preventing fibrosis and heterotopic bone formation. Patients and Methods: Records of 115 patients (5 males, 110 females) that underwent autologous fat grafts simultaneously with total joint prosthetic reconstruction (Christensen or TMJ Concepts) were evaluated. There were 88 patients with bilateral and 27 patients with unilateral reconstruction for a total of 203 joints. All patients had total joint prosthesis placed and stabilized followed by autologous fat (harvested from the abdomen) packed around the articulating portion of the joint prosthesis. Clinical assessment was performed at 3 time intervals; presurgery (T1), immediately postsurgery (T2), and longest follow-up (T3). Objective clinical evaluation included maximum incisal opening (MIO) and lateral excursions (LE). Subjective evaluation included jaw function. Radiographic (panoramic, linear tomograms, and lateral cephalograms) evaluation was performed by comparing T2 and T3 x-rays for presence of heterotopic bone formation around the prosthesis. Complications at the donor site were also evaluated. Student’s t-test was utilized at P ⱕ .01 value level. Results: The average patient follow-up was 31.2 months (range, 6 to 65 months). There were 76 joints reconstructed with Christensen total joint prosthesis (group 1) and 127 joints reconstructed with TMJ Concepts prosthesis (group 2). There was a statistically significant difference in MIO and patient perception of jaw function in both groups; no significant difference was found for lateral excursions. There was no radiographic evidence of heterotopic bone formation in either group at longest follow-up. There were 25 Christensen prostheses removed because of elevated pain levels due to device failure or metal hypersensitivity; no fibrosis or heterotopic bone formation around the prostheses were observed at surgical removal. At donor site evaluation, 10 patients (11%) developed complications: 2 obese patients developed abdominal cysts superficial to the rectus abdominis muscle that required surgical removal; 8 patients (6%) developed seroma formation requiring aspiration; and 2 patients had drains placed postsurgery. AAOMS • 2001

LE (mm)

Jaw Function VAS Score 0 ⫽ normal function— 10 ⫽ no function

T1

T3

T1

T3

T1

T3

23.6 27.6

27.1* 34.4*

1.5 3.4

1.3 2.0

7.7 7.6

5.8* 5.2*

* Significant at 0.01 level

Conclusions: The results of this study demonstrate the efficacy of autologous fat grafts in temporomandibular joint reconstruction using a total joint prosthesis. A statistically significant improvement for both groups was found regarding MIO and patient perception of jaw function. The removal of 25 prostheses was due to problems unrelated to the fat grafts. No evidence of fibrosis or heterotopic bone formation was radiographically or clinically observed. The most common complication at the donor site was seroma, which was managed with aspiration and pressure dressing. References Wolford LM, Karras SC: Autologous fat transplantation around temporomandibular joint total joint prostheses: Preliminary treatment outcomes. J Oral Maxillofac Surg 55:245; discussion, 251, 1997 Wolford LM, Cottrell DA, Henry CH: Temporomandibular joint reconstruction of the complex patient with the Techmedica custommade total joint prosthesis. J Oral Maxillofac Surg 52:2; discussion, 11, 1994

POSTER 44 Efficacy of Bispectral Monitoring for Outpatient Oral Surgery Procedures Anthony Bowie, DMD, 39 Colleton Dr, Charleston, SC 29407 (Durwood E. Bach, DDS) The purpose of this investigation was to evaluate the accuracy and consistency of the Bispectral monitor in measuring the plane of sedation in patients undergoing third molar extractions. Methods: Forty volunteer patients indicated for third molar extraction surgery using 1 of 2 anesthetic techniques from December 2000 to March 2001. In the experimental group, the Bis monitor recordings were in sight of the surgeon and were utilized to maintain the level of sedation. In the control group, the Bis monitor was out of sight of the surgeon. The level of sedation was determined by traditional parameters. In both groups, Bis readings were recorded at 2-minute intervals. Attention was given to recording Bis values at the time of maximum surgical stimulation. A designated observer recorded patient movements, oxy121

Scientific Poster Session gen saturation, blood pressure, pulse, Bis value, anesthetic dose, dosing intervals, and final total anesthetic dose. Postoperatively, the patient was asked to complete 2 surveys. One judged patient recall intraoperatively and the other patient satisfaction. Data were analyzed by chi-square for statistical significance and by subjective observer analysis. Results: In the experimental group, 10 patients were sedated with propofol cocktails and 10 with brevital. None of the 20 patients had recall after the procedures, the average Bis reading in the propofol group was 63 and in the brevital group 67. The average dose of propofol per a patient was 1.14 mg/kg and 1.34 mg/kg for brevital. The control was split with 10 patients in the propofol group and 10 in the brevital. Two of the patients stated they had some recall during the procedure, both in the brevital group. The average Bis reading in the propofol group was 75 and in the brevital group it was 73. The average dose of propofol was 0.87 mg/kg and 0.91 mg/kg for the brevital group. Conclusion: The Bis monitor was beneficial when sedating patients for third molar surgery. In the test group, the operator was able to deepen the sedation to a comfortable level where there was no patient movement. In the control group the patients had greater movement throughout the case. The average dose of propofol/brevital was greater for the experimental group. When the operator sedated a patient to a comfortable level, the Bis monitor allowed the operator to keep the patient at that level. If the Bis value started to rise, a bolus was administered before the patient’s sedation became light. In the control group, a bolus was administered usually after there was a sign that the sedation had become light, usually movement. No patient had recall in the experimental group. Two patients had recall in the control group. The Bis monitor did accurately and predictably measure a patient’s sedation level during third molar extractions. It allowed the operator to adjust the sedation level to a plane in which the patient’s movements were at a minimum and without any intraoperative recall. References Liu J, Singh H, White P: Electroencephalogram bispectral analysis predicts the depth of midazolam-induced sedation. Anesthesiology 84:64, 1996 Glass P, Bloom M, Kearse L, et al: Bispectral analysis measures sedation and memory effects of propofol, midazolam, isoflurane, and alfentanil in healthy volunteers. Anesthesiology 86:834, 1997 Katoh T, Suzuki A, Ikeda K: Electroencephalographic derivatives as a tool for predicting the depth of sedation and anesthesia induced by sevoflurane. Anesthesiology 88:642, 1998

Funding Source: Department of Oral/Maxillofacial Surgery, Medical University of South Carolina.

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POSTER 45 Is Surgical Experience the Main Determining Factor on the Success of Implants? Shahin Shahgoli, DDS, 246 East 71st St, Apt 1B, New York, NY 10021 (Andre Montazem, DMD, MD) The purpose of this study is to re-evaluate the role of surgical experience as a major determining factor on the success rate of osseointegrated implants. The Problem: There have been multiple reports in the literature that discuss the positive effect of increased surgical experience on the success rate of implants. Lambert et al showed in their study from 1997 that there is a learning curve for implant placement. They concluded that practitioners with little experience (⬍50 implants) had twice the failure rate of practitioners with more experience (⬎50 implants). Furthermore, Preiskel et al stated in their retrospective study from 1995 that the surgeon’s experience had a major impact on the failure rate of implants. All of these studies have grouped multiple surgeons into experienced and inexperienced categories. To our knowledge, no study has looked at the result for a single surgeon. In addition, most of these studies have looked specifically at stage II results and not the reconstruction phase, which can lead to erroneous conclusions since not all successfully integrated implants can be restored. These results suggest that inexperienced practitioners might place their patients at a higher risk for treatment failure. With this study we attempt to show that the lack of experience is not the major determinant in treatment outcome. Lack of experience can be successfully compensated for by following a thorough preoperative workup and by performing the procedure under guidance of an experienced practitioner. Materials and Methods: A 5-year follow-up of the first 52 implants placed by a single oral and maxillofacial surgeon is presented. All 52 implants have been placed by the same practitioner using a meticulous preoperative workup and prosthetic planning. To our knowledge this is the first study to look at the result of a single surgeon. The first 20 implants were placed under the close supervision and guidance of an experienced practitioner and the rest were placed by the surgeon alone. All patients have been followed up for up to 5 years after implant placement and up to 4 years after prosthetic reconstruction. By assessing the results of a single practitioner we are able to eliminate the major variable of multiple practitioners and correlate the treatment outcome directly to the experience of the surgeon. Results: There was no correlation seen between the increased surgical experience of the practitioner and the success rate of the placed implants. From the 52 implants placed only 2 were lost, both in the same patient, a smoker. All other implants integrated successfully, AAOMS • 2001

Scientific Poster Session were restored prosthetically, and are currently under function. This is a success rate of 96.1% that is in accordance to the reported success rate of comparable studies in the literature. Conclusions: Under the guidance of an experienced surgeon even inexperienced practitioners can achieve satisfactory results. We believe that appropriate treatment planning, a preoperative prosthetic workup, appropriate radiographs, and the fabrication of a surgical stent in conjunction with the supervision of an experienced surgeon can compensate for the lack of experience in the practitioner. If all the previously mentioned parameters are observed, we feel that the patients are not being exposed to a greater risk of implant failure when being treated by an inexperienced surgeon. This study is the first part of an extensive study, which is currently ongoing in our institution to assess the rates of implant success in a resident group in correlation to surgical experience. References Lambert et al: J Oral Maxillofac Surg 55:12, 1997 (suppl 5) Preiskel et al: Int J Prosthodontics 8:273, 1995

POSTER 46 Noma in Sudan Kamal Abbas, BDS, University of Khartoum, Faculty of Dentistry, PO Box 102, Khartoum, Sudan Noma (cancrum oris) is an often fatal oral disease that leaves its victims mutilated for the rest of their lives. It affects weak, undernourished children aged 1 to 6 years and is usually preceded by severe illness, such as measles or malaria. The disease starts as an ulcer on the gingival or oral mucosa of the patient and rapidly extends to a gangrenous lesion that destroys the muscle and the bone, leaving a large facial deformity. Nutrition, sanitary conditions, and illiteracy play a great role. Sudan, an African sub-Saharan country with an area of one million square miles, has a population of 30 million. Sudan is one of the poorest African countries, with a high illiteracy rate, poor roads, and a very meager health service. The country has been subjected to drought in addition to 50 years of civil war. The neighboring countries suffer the same, leading to citizen displacement in addition to refugees. In Khartoum Dental Teaching Hospital, a pilot study is currently ongoing to study the incidence of noma patients. They usually come to the hospital in the late stages of the disease, looking for reconstruction of the facial defects. Thirty patients were seen during the years 1996-2000. Age, sex, social status, literacy of the parents, number in family, father’s profession, income and history of serious childhood illness were questioned. AAOMS • 2001

It was found that most of the patients came from a low socioeconomic class and their living environment was really poor. The facial defects mostly affect the lips, cheek, alveolar bone, and fusion between maxilla and mandible. All the affected had experienced severe childhood illness. Noma is a bacterial infection that can easily be intercepted through parent education on early management of the disease and the availability of easy access to medicine to cure the gum condition.

POSTER 47 Effect of a Modified Activator Device in the Treatment of Obstructive Sleep Apnea Syndrome Heinrich Strobl, MD, DMD, University of Innsbruck, Department of Oral and Maxillofacial Surgery, Maximilianstrasse 10, Innsbruck, 06020, Austria (Ferenc Tracik, MD; Ru ¨ diger Emshoff, MD, DMD) In the treatment of the obstructive sleep apnea syndrome (OSAS) multiple surgical procedures designed to increase the posterior airway space have been devised. Several authors described dental appliances to be somewhat effective in patients with OSAS. However, the question of how these appliances work and why they may be effective in some patients but not in others remains a point of controversy. The purpose of this study was to evaluate the long-term effect of a modified activator device (MAD) on signs and symptoms of OSAS. With OSAS defined as a sleep-related breathing disorder (SRBD) characterized by 5 at least 10-second long apneas per hour sleep (respiratory disturbance index, ⬎5), the study consisted of 75 patients showing mild to severe OSAS with a respiratory disturbance index (RDI) between 5 and 59. Each patient received an individual MAD designed to increase vertical dimension and protrude the mandible. Polysomnography performed at the Laboratory of Sleep-Related Disorders was used to compute RDI before treatment and at 15-month follow-up. MAD treatment resulted in a significant decrease of the pretreatment RDIs (P ⬎ .01). In patients with pretreatment RDIs ranging from 40 to 59 the respective decrease was more significant than in those showing values from 20 to 40. The results suggest application of MADs as a cost-effective and rational approach for patients with OSAS. References Barthlen GM, Brown LK, Wiland MR, et al: Comparison of three oral appliances for treatment of severe obstructive sleep apnea syndrome. Sleep Med 1:299, 2000 Petitjean T, Chammas N, Langevin B, et al: Principles of mandibular advancement device applied to the therapeutic of snoring and sleep apnea syndrome. Sleep 23:S166, 2000 (suppl 4)

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POSTER 48 Tibial Bone Grafting: A Quantitative Anatomical Study and Description of a Technique Brett King, DDS, School of Dentistry, Department of Oral and Maxillofacial Surgery, 11234 Anderson St, Loma Linda, CA 92350 (Alan Herford, DDS, MD; Franco Audia, DDS) Purpose: The purpose of this study is to quantify the amount of bone graft material present in the proximal tibia via the lateral versus the medial approach, as well as describe an alternative technique for obtaining this bone graft material. A quantitative anatomic and statistical analysis and comparison are presented. The goal of this study is to demonstrate the advantages and simplicity associated with utilizing the medial proximal tibia as a bone graft harvest site in oral and maxillofacial surgery. Material and Methods: Forty lower extremities from 20 cadavers were studied. All specimens were meticulously dissected and anatomic landmarks were recorded. Anatomic structures including vessels, nerves, muscle attachments, and articular surfaces, and their relationships to the various anatomical landmarks were identified, measured with a linear millimeter ruler, and recorded. Bone harvest was accomplished using either a medial (20 extremities) or lateral (20 extremities) approach. A template was used to scribe a 10-mm round site for harvest, and the bone was procured with bone curettes. The amount of bone available for harvest using both techniques was compared. Variables evaluated included volume of graft, age, gender, and interpositional relationships among anatomic structures. Results: The mean volume of bone harvested was 25.0 mL for the lateral approach and 24.9 for the medial approach (range, 14 to 34 mL). The Mann-Whitney U test revealed no significant difference in mean volume of graft obtained when comparing the medial or lateral approaches (P ⫽ .9250). Pearson’s correlation test revealed no correlation between age (.089 medial and 0.174 lateral) or gender (P ⫽ .3120 medial and P ⫽ .4440 lateral). When comparing the medial anatomic structures, the average distance of the saphenous nerve and vein from the tibial tuberosity was 73.8 mm and 75.5 mm, respectively. The average length of the pes anserinus was 41.95 mm. The pes anserinus was routinely found 4.85 mm below the tibial perpendicular line (Tperp) and its superior attachment was found 11.4 mm medial to the tibia parallel line (Tpara). The lateral anatomic structures evaluated included the anterior tibial vessels which emerged from the interosseous hiatus 14.3 mm inferior to Tperp and 42.6 mm lateral to the Tpara line. The distance from the tibial perpendicular to the articular surface did not significantly differ when comparing the medial (33.65 mm) and lateral (33.25 mm) 124

anterior tibial surfaces. The mean length of the oblique line was 17.9 mm and the superior portion of this line was 14.65 mm above the Tperp line. Conclusions: Equal amounts of bone graft material are available for harvest from the medial and lateral aspects of the proximal tibia. Knowledge of important anatomic landmarks can be used preoperatively to allow for safe dissection and harvest of autogenous bone from the proximal tibia. Using anatomic landmarks such as the tibial tuberosity, Gerdy’s tubercle, and the center of the patella as a basis, a simple and safe technique for harvesting tibial bone from the medial aspect is described. The dissection of medial proximal tibia and harvest of bone graft material may be accomplished efficiently with minimal chances of damage or morbidity to vital adjacent structures. References Catone GA, Reimer BL, McNeir D, et al: Tibial autogenous cancellous bone as an alternative donor site in maxillofacial surgery: A preliminary report. J Oral Maxillofac Surg 50:1258, 1992 O’keefe RM, Reimer BL, Butterfield SL: Harvesting of autogenous cancellous bone graft from the proximal tibial metaphysis: A review of 230 cases. J Orthop Trauma 5:469, 1991 Funding Source: Department.

POSTER 49 Oral Myiasis in the United States Michael Safian, DDS, 4 Tumblebrook Road, Woodbridge, CT 06525 (Guy Jirawuthiwaravong, MD; Elena Citkowitz, MD, PhD) Introduction: Myiasis is an infestation of mammals by fly larvae. The condition occurs in rural or tropical areas, but is rare in developed nations. Most cases in humans occur in warm climates or unsanitary conditions. Oral myiasis was first described in 1909 and is a condition rarely reported in the current literature. All cases occurred either in rural areas of developing nations or in patients in the industrialized West who had recently returned from such areas. We report an unusual presentation of oral myiasis occurring in New Haven, CT. Case: An 83-year-old female with no significant past medical history was admitted to the hospital with lethargy, dehydration, and a fever of 101.4°F. For several years prior to admission, the patient had been living alone, reportedly in unsanitary conditions. On the day of admission, she was found lying on the floor in her home, soiled by her own feces. On examination, the patient was well-developed, dehydrated, agitated, and screaming obscenities. Examination of the oral cavity revealed nonulcerated dry mucosa, a maxillary complete denture, and 3 white, segmented organisms (3 mm ⫻ 1 mm) moving along the denture, the buccal mucosa, and the lips. Laboratory results were unremarkable except for an AAOMS • 2001

Scientific Poster Session elevated BUN of 63 and creatinine of 1.3. The organisms were removed at the bedside. Presumed to be insect larvae, they were sent for analysis to a US Department of Agriculture entomologist who identified them as second instar larvae of the order Diptera, family Sarcophagidae, commonly known as the flesh fly. The patient was rehydrated and later discharged to an extended care facility. Discussion: Larvae of many different families of flies cause oral myiasis. Curative treatment is simple or surgical removal of the infesting organisms. Ulcerations or gingival burrows must be surgically explored, often multiple times, to ensure adequate debridement and extermination. An important consideration in the management of oral myiasis is the possible ingestion of larvae; acute enteritis has been described following enteric infection. We believe this is the first report of oral myiasis in a patient living in a Western industrialized nation who had no recent travel history. The fact that this occurred during a summer of record-breaking temperatures in the Northeastern US may not be coincidental. Oral myiasis should be considered a possibility, even in the most developed of nations, and patients with documented poor hygiene and unsanitary living conditions should be screened for such infestations. References Felices R, Ogbureke K: Oral myiasis: Report of case and review of management. J Oral Maxillofac Surg 54:219, 1996 Lata J, Kapila B, Aggarwal P: Oral myiasis: A case report. Int J Oral Maxillofac Surg 25:455, 1996 Gunbay S, Bicakci N, Canda T, et al: A case of myiasis gingiva. J Periodontol 66:892, 1995

POSTER 50 Maxillofacial Reconstruction With Maxillofacial Prostheses and Osseointegrated Implants Corwin D. Martin, DDS, MD, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9109 (Tantipasawasin Sittichai, DDS; Douglas P. Sinn, DDS) Maxillofacial defects result from many causes, both congenital and acquired. Congenital deformities, injuries, and cancer are the most common. Facial defects,

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especially of the nose, eyes, or ear, are easily noticeable. They are devastating to the patient, both physically and emotionally. Since the 16th century, there is documentation of trying to reconstruct ears and other missing parts. Alloplastic materials, skin flaps, and costal cartilage have all been used for this reconstruction. Though some are satisfactory, many leave much to be desired. It is difficult to achieve simultaneously an aesthetic result and good retention in patients with poor soft tissue or in patients with compromised conditions, ie, postradiation therapy. In 1979, Branemark introduced the percutaneous osseointegrated implants for retention of auricular prostheses follow by nose prostheses, orbital prostheses, and midface prostheses. With increased skill and interest the maxillofacial prosthetist can provide improved reconstruction and good retention can be expected. This retrospective study includes 23 prostheses in 18 patients that have been treated with implant (ITI) retained maxillofacial prostheses at the University of Texas, Southwestern Medical Center, Division of Oral and Maxillofacial Surgery, from 1998 to 2000. Congenital causes are the most common, followed by skin cancer and injury, respectively. Facial defects included ear deformities (12), missing eyes (7), loss of eyebrow (2), and nose avulsion (1). Patients’ ages ranged from 2 to 76 years and follow-up ranged from 1 to 7.5 years (mean, 3 years). Of the 71 maxillofacial implants placed, 5 of them from 2 patients were lost leaving a success rate 93%. A discussion of diagnosis, patient selection, complications, and overall management will be part of the presentation. Craniofacial extraoral osseointegrated implants offer certain advantages including excellent aesthetic results and retention. This should be the treatment of choice for reconstruction of ears, eyes, or the nose. The success depends on patient selection and coordination between the oral and maxillofacial surgeon and maxillofacial prosthetist. References Tjellstrom A, Lindstrom J, Hallen O, et al: Osteointegrated titanium implants in the temporal bone. A clinical study on bone-anchored hearing aids. Am J Otology 2:304, 1981 Albrektsson T, Branemark P-I, Jacobsson M, et al: Present clinical application of osseointegrated percutaneous implants. Plast Reconstr Surg 79:721, 1987

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