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Poster 059: Surgically Assisted Rapid Canine Distraction
Scientific Poster Session vested at end-DO (n⫽3), mid-fixation (n⫽3) and end fixation (n⫽3). These were examined clinically and radiographically. One minipig maxilla was used as a control. The harvested maxillas were divided in two (between the central incisors) and each of the specimens was further divided into 2 areas of interest (piriform aperture, zygomatic buttress) resulting in a total of 12 specimens at each time point. All harvested specimens (n⫽ 36) were fixed, decalcified, and divided in 2 (for coronal and sagittal examination) and were then embedded in paraffin. All the specimens were sectioned at 5-m intervals, mounted on fisher-frost slides, and stained with hematoxyline/eosin, TRAP for osteoclasts identification, collagen II for cartilage, CD 34 for endothelial cells and PCNA immunohistostaining for proliferating cells. Method of Data Analysis: Images x200 were taken of the H&E, collagen II, TRAP, CD34 and PCNA slides. Computer histomorphometric analysis and histological evaluation were performed using the H&E slides to determine percent surface area of hematoma, fibrous tissue, cartilage, vessels, mature and immature bone in all groups. The data was analyzed using the twosample t-test. PCNA index was defined as the number of positive nuclei per 10 high-power fields at x200 magnification. Two independent blinded observers scored the slides. Results: At the end-DO group three zones were identified in each half of the regenerate: a cellular zone at the centre, a collagenous zone, and a zone with new woven bone trabeculae in continuity with the natural bone. Fibrous tissue decreased sequentially in the end-DO, mid-fixation, and end-fixation groups. PCNA index and vessel density were higher at the end-DO group compared to mid-fixation and end-fixation groups. Osteoclasts were more prominent at the end-fixation group. No cartilaginous tissue was revealed in the regenerate with collagen II immunohistochemistry in any group. At end fixation the regenerate consisted of bone trabeculae rimmed by osteoblasts. Conclusion: Maxillary osteogenesis at the Le Fort I level after distraction is intramembranous. By the end of the distraction period there is active proliferation of pro-osteblasts and formation of bone trabeculae in young subjects. At end fixation there is bony union across the gap with few areas of fibrous tissue. References Glowacki J, Shusterman M, Troulis M, Holmes R, Perrott D, Kaban LB: Distraction Osteogenesis of the Porcine Mandible: Histomorphometric Evaluation of Bone. Plast Reconstr Surg. 2004 Feb; 113(2): 566-73 Rachmiel A, Rozen N, Peled M, Lewinson D. Characterization of midface maxillary membranous bone formation during distraction osteogenesis. Plast Reconstr Surg 2002: 109: 1611-1620
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POSTER 059 Surgically Assisted Rapid Canine Distraction Elif I Keser, DDS, PhD, Dubai (Pober R; Mehra P; Van Heukelom E) Introduction: Extraction of premolar teeth for orthodontic treatment of crowding and protrusion is a common procedure performed by oral surgeons. Post extractions, distalization of canines using conventional orthodontic techniques takes approximately 6 to 8 months. The concept of “distracting the periodontal ligament” to shorten the canine distalization time to 3 weeks has been proposed, and is termed “dental distraction”. This technique requires modification of the extraction socket by undermining the interseptal bone distal to the canine and utilizes standard distraction osteogenesis principles. This combined surgical-orthodontic technique significantly shortens the treatment time required for orthodontic canine distalization, when compared to conventional orthodontic therapy. Patients and Methods: Three patients (ages 12, 17, and 30 years) were planned for surgically assisted rapid orthodontic canine distraction. Two of the three patients had bimaxillary protrusion, deep bites, and mild upper- and moderate lower-dentition crowding. Extraction of all four first bicuspids was planned for reducing the facial profile and alleviate the crowding. The third patient had a severe skeletal Class II malocclusion. The extraction of lower first premolars was indicated for the decompensation prior to orthognathic surgery. Molar and canine bands were placed and incisors were bracketed prior to surgery. Surgical procedure: After premolar extraction, the interseptal bone distal to the canine was undermined with a round surgical bur. Vertical grooves were made inside the extraction socket, along the buccal and lingual extraction socket margins and extended obliquely toward the base of the interseptal bone to weaken it. Thus, the volume of alveolar bone on the distal aspect of the canine root was surgically reduced to facilitate subsequent orthodontic movement of the canines by decreasing resistance. The procedure was similarly completed in the remaining three quadrants. The distraction devicesⴱ were placed immediately post surgery and activation initiated the following day. Patients were instructed to activate the appliance twice daily. No additional anchorage devices were used. Results: Canine retraction was completed in 6 weeks in the first patient, 14 days in the second patient, and only ten days in the third patient. The first patient took longer than expected because of compliance issues. Gingival pocketing and health of periodontal structures was similar to preoperative observations. No surgical or orthodontic complications were encountered. None of the patients complained about use of the distraction device. AAOMS • 2008
Scientific Poster Session Conclusion: Surgically assisted rapid canine retraction is a very effective, safe, office-based technique that has the potential to dramatically shorten total treatment time in patients undergoing orthodontic therapy who require extraction of premolar teeth. The technique can also be effectively used to shorten the preoperative orthodontic treatment duration in orthognathic surgery patients. References Reitan K: Clinical and histological observations on tooth movement during and after orthodontic treatment, Am. J. Orthod. 53:721-45, 1967 Rygh P: Elimination of hyalinized periodontal tissues associated with orthodontic tooth movement, Scand. J. Dent. Res. 80:57-73, 1974 Liou EJW, Huang CS: Rapid canine retraction through distraction of the periodontal ligament, Am. J. Orthod. Dentofacial Orthop. 114:37282, 1998 ⴱ Distraction device- patent pending. (Keser EI, Pober R)
POSTER 060 Correction of Velopharyngeal Insufficiency in Cleft Palate Patients Using the Furlow Conversion Palatoplasty Kristopher W. Lee, DDS, University of Michigan, 1500 E Medical Center Drive, TC B1-208 Ann Arbor, MI 48197 (Berger M; Edwards SP) Problem: Post palatoplasty velopharyngeal dysfunction remains a vexing problem in the care of a child with a cleft palate with an incidence ranging from 5-25%. VPD has a significant impact on a patient’s self confidence, communication skills, and quality of life. Many therapeutic options exist for the management of this condition and are based on a thorough diagnostic evaluation of the etiology for the dysfunction. Velopharyngeal insufficiency, referring to a structural defect, is generally addressed surgically. These surgical options are broadly directed at either the palate itself or the pharynx. Pharyngoplasty techniques have enjoyed good success rates in the treatment of hypernasal resonance but are often complicated by the development of hyponasality and in some patients will result in sleep disordered breathing. Secondary palatal procedures offer the potential to address the structural defect while avoiding the development of hyponasality and potentially a lower risk of sleep apnea. Methods: Patients presenting to the Pediatric Oral and Maxillofacial Surgery Clinic at the University of Michigan underwent a thorough evaluation by a surgeon and speech language pathologist consisting of a physical exam, perceptual speech exam performed by the speech therapist, nasometry, and fiberoptic nasopharyngoscopy. Those children who were identified to have velopharyngeal insufficiency and were felt to have a correctable anatomic defect in their palate were offered a FurAAOMS • 2008
low conversion palatoplasty. This correctable defect in all cases was a sagittal orientation of the levator palatine muscle bundles in addition to a deficiency in length. Emphasis was placed on re-establishing a properly oriented levator sling with complete mobilization of the muscle bundles into the space of Ernst to permit a transverse re-orientation. All patients were evaluated at 3 and 6 months postoperatively using the same modalities. Results: During the period of June 2006 through March 2008, 7 patients underwent Furlow conversion palatoplasty. Two patients had previously undergone a primary palatoplasty with the Furlow technique. The mean age was 18.43 years (range 4-46). There were no complications intra or postoperatively. The length of hospital stay postoperatively was 1.4 days (range 1-2). No patient developed a fistula postoperatively. Complete follow up speech testing, consisting of a perceptual exam performed by a speech pathologist, nasometry, and nasoendoscopy was available for four of these patients with the others pending. Perceptual speech exam alone was available for one additional patient. No patient developed symptoms concerning for sleep apnea (snoring, witnessed apneas, neurobehavioral problems). Resonance was classified into normal, mild, moderate, and severe hyper and/or hyponasality by perceptual exam. Most patients experienced an initial decline in their resonance with increased nasality in the immediate postoperative period. This was however, a transient finding with all patients improving by at least one category postoperatively. No patients to date have gone on to have a pharyngoplasty. Furthermore, all patients postoperatively had a competent velopharyngeal mechanism at the single word level, 2/4 at the sentence level or above, by perceptual exam and nasoendoscopy. No patients experienced a worsening of their hyponasality after surgery. Nasometry readings and nasoendoscopic findings were consistent with the perceptual exam and showed similar improvements. Conclusions: Our preliminary results show that Furlow conversion palatoplasty is a low morbidity procedure that can be used to improve mobility and length of the velum thereby improving VPD symptoms. Unlike the myriad of pharyngoplasty techniques, the Furlow conversion palatoplasty does not seem to worsen hyponasality, or symptoms of sleep disordered breathing. References Chen PK, Wu JT, Chen YR, Noordhoff MS. Correction of secondary velopharyngeal insufficiency in cleft palate patients with the Furlow palatoplasty. Plast Reconstr Surg. 1994 Dec;94(7):933-41 Chen PK, Wu J, Hung KF, Chen YR, Noordhoff MS. Surgical correction of submucous cleft palate with Furlow palatoplasty. Plast Reconstr Surg. 1996 May;97(6):1136-46
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POSTER 059 Surgically Assisted Rapid Canine Distraction Elif I Keser, DDS, PhD, Dubai (Pober R; Mehra P; Van Heukelom E) Introduction: Extraction of premolar teeth for orthodontic treatment of crowding and protrusion is a common procedure performed by oral surgeons. Post extractions, distalization of canines using conventional orthodontic techniques takes approximately 6 to 8 months. The concept of “distracting the periodontal ligament” to shorten the canine distalization time to 3 weeks has been proposed, and is termed “dental distraction”. This technique requires modification of the extraction socket by undermining the interseptal bone distal to the canine and utilizes standard distraction osteogenesis principles. This combined surgical-orthodontic technique significantly shortens the treatment time required for orthodontic canine distalization, when compared to conventional orthodontic therapy. Patients and Methods: Three patients (ages 12, 17, and 30 years) were planned for surgically assisted rapid orthodontic canine distraction. Two of the three patients had bimaxillary protrusion, deep bites, and mild upper- and moderate lower-dentition crowding. Extraction of all four first bicuspids was planned for reducing the facial profile and alleviate the crowding. The third patient had a severe skeletal Class II malocclusion. The extraction of lower first premolars was indicated for the decompensation prior to orthognathic surgery. Molar and canine bands were placed and incisors were bracketed prior to surgery. Surgical procedure: After premolar extraction, the interseptal bone distal to the canine was undermined with a round surgical bur. Vertical grooves were made inside the extraction socket, along the buccal and lingual extraction socket margins and extended obliquely toward the base of the interseptal bone to weaken it. Thus, the volume of alveolar bone on the distal aspect of the canine root was surgically reduced to facilitate subsequent orthodontic movement of the canines by decreasing resistance. The procedure was similarly completed in the remaining three quadrants. The distraction devicesⴱ were placed immediately post surgery and activation initiated the following day. Patients were instructed to activate the appliance twice daily. No additional anchorage devices were used. Results: Canine retraction was completed in 6 weeks in the first patient, 14 days in the second patient, and only ten days in the third patient. The first patient took longer than expected because of compliance issues. Gingival pocketing and health of periodontal structures was similar to preoperative observations. No surgical or orthodontic complications were encountered. None of the patients complained about use of the distraction device. AAOMS • 2008
Scientific Poster Session Conclusion: Surgically assisted rapid canine retraction is a very effective, safe, office-based technique that has the potential to dramatically shorten total treatment time in patients undergoing orthodontic therapy who require extraction of premolar teeth. The technique can also be effectively used to shorten the preoperative orthodontic treatment duration in orthognathic surgery patients. References Reitan K: Clinical and histological observations on tooth movement during and after orthodontic treatment, Am. J. Orthod. 53:721-45, 1967 Rygh P: Elimination of hyalinized periodontal tissues associated with orthodontic tooth movement, Scand. J. Dent. Res. 80:57-73, 1974 Liou EJW, Huang CS: Rapid canine retraction through distraction of the periodontal ligament, Am. J. Orthod. Dentofacial Orthop. 114:37282, 1998 ⴱ Distraction device- patent pending. (Keser EI, Pober R)
POSTER 060 Correction of Velopharyngeal Insufficiency in Cleft Palate Patients Using the Furlow Conversion Palatoplasty Kristopher W. Lee, DDS, University of Michigan, 1500 E Medical Center Drive, TC B1-208 Ann Arbor, MI 48197 (Berger M; Edwards SP) Problem: Post palatoplasty velopharyngeal dysfunction remains a vexing problem in the care of a child with a cleft palate with an incidence ranging from 5-25%. VPD has a significant impact on a patient’s self confidence, communication skills, and quality of life. Many therapeutic options exist for the management of this condition and are based on a thorough diagnostic evaluation of the etiology for the dysfunction. Velopharyngeal insufficiency, referring to a structural defect, is generally addressed surgically. These surgical options are broadly directed at either the palate itself or the pharynx. Pharyngoplasty techniques have enjoyed good success rates in the treatment of hypernasal resonance but are often complicated by the development of hyponasality and in some patients will result in sleep disordered breathing. Secondary palatal procedures offer the potential to address the structural defect while avoiding the development of hyponasality and potentially a lower risk of sleep apnea. Methods: Patients presenting to the Pediatric Oral and Maxillofacial Surgery Clinic at the University of Michigan underwent a thorough evaluation by a surgeon and speech language pathologist consisting of a physical exam, perceptual speech exam performed by the speech therapist, nasometry, and fiberoptic nasopharyngoscopy. Those children who were identified to have velopharyngeal insufficiency and were felt to have a correctable anatomic defect in their palate were offered a FurAAOMS • 2008
low conversion palatoplasty. This correctable defect in all cases was a sagittal orientation of the levator palatine muscle bundles in addition to a deficiency in length. Emphasis was placed on re-establishing a properly oriented levator sling with complete mobilization of the muscle bundles into the space of Ernst to permit a transverse re-orientation. All patients were evaluated at 3 and 6 months postoperatively using the same modalities. Results: During the period of June 2006 through March 2008, 7 patients underwent Furlow conversion palatoplasty. Two patients had previously undergone a primary palatoplasty with the Furlow technique. The mean age was 18.43 years (range 4-46). There were no complications intra or postoperatively. The length of hospital stay postoperatively was 1.4 days (range 1-2). No patient developed a fistula postoperatively. Complete follow up speech testing, consisting of a perceptual exam performed by a speech pathologist, nasometry, and nasoendoscopy was available for four of these patients with the others pending. Perceptual speech exam alone was available for one additional patient. No patient developed symptoms concerning for sleep apnea (snoring, witnessed apneas, neurobehavioral problems). Resonance was classified into normal, mild, moderate, and severe hyper and/or hyponasality by perceptual exam. Most patients experienced an initial decline in their resonance with increased nasality in the immediate postoperative period. This was however, a transient finding with all patients improving by at least one category postoperatively. No patients to date have gone on to have a pharyngoplasty. Furthermore, all patients postoperatively had a competent velopharyngeal mechanism at the single word level, 2/4 at the sentence level or above, by perceptual exam and nasoendoscopy. No patients experienced a worsening of their hyponasality after surgery. Nasometry readings and nasoendoscopic findings were consistent with the perceptual exam and showed similar improvements. Conclusions: Our preliminary results show that Furlow conversion palatoplasty is a low morbidity procedure that can be used to improve mobility and length of the velum thereby improving VPD symptoms. Unlike the myriad of pharyngoplasty techniques, the Furlow conversion palatoplasty does not seem to worsen hyponasality, or symptoms of sleep disordered breathing. References Chen PK, Wu JT, Chen YR, Noordhoff MS. Correction of secondary velopharyngeal insufficiency in cleft palate patients with the Furlow palatoplasty. Plast Reconstr Surg. 1994 Dec;94(7):933-41 Chen PK, Wu J, Hung KF, Chen YR, Noordhoff MS. Surgical correction of submucous cleft palate with Furlow palatoplasty. Plast Reconstr Surg. 1996 May;97(6):1136-46
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