- Email: [email protected]
Bisphosphonate-associated osteonecrosis (BON) of the jaws: A possible treatment?
1460
LETTERS TO THE EDITOR
to present an alternative, successful method for treatment/ elimination of a ranula—which has a notorious history of poor response to surgical care. In the 45 years of my OMFS career I have been privileged to treat these lesions, mostly in young patients, and have had a multiplicity of patient and parental complaints resulting from the technique of packing in regards to postoperative discomfort and the necessity, in my hands, for retreatment. As to the procedure itself: A trapdoor-shaped flap was first outlined so as to permit grasping of its margin to facilitate the final incision for unroofing. The cotton swab inspection of the base was performed to preclude missing an incipient deep extension prior to scarifying the base by defocusing the laser. In truth, however, the swab probably served little purpose in the hands of the parents at home. The successful healing was, I believe, a result of the laserbased treatment itself. While only a 14-day clinical follow-up was available, the lack of any complaint or return to clinic by the patient/ parent in over a year (nor inquiries from other surgeons in the area to whom the patient may have appeared for secondary care), indicated that the treatment was definitive. Finally, with complete absence of postoperative pain or bleeding as reported by the patient/parent, absent the need for any placement or removal of sutures, and with the ability to identify and avoid vital structures in the area as the Waterlase cut through the superficial tissues at a slow, controlled rate, I believe that this modality offers the surgeon a worthwhile addition to his armamentarium. MALCOLM ZOLA, DDS Bronx, NY
FIGURE 1. Coronal MRI highlighting tumor in right palate involving the floor of the maxillary sinus.
healed without event and there was no evidence of recurrence. MARK J.A. TURNER, BDS, MB, BCHIR, MA, FDSRCS, MRCS WILLIAM P. SMITH Northampton, UK
References doi:10.1016/j.joms.2006.06.253
AN EXCEPTIONALLY LATE RECURRENCE OF PLEOMORPHIC ADENOMA To the Editor:—We would like to highlight late recurrence of pleomorphic adenoma of the palate and the importance of warning the patient of the risk. The following case highlights the long latency (35 years) between initial excision and recurrence. A 54-year-old woman was urgently referred by her general dental surgeon with a 3-month history of persistent, painless, slow-growing palatal swelling. Clinical examination revealed a swelling of her palate at the site where 35 years earlier she had undergone an excision biopsy. The primary lesion, histologically confirmed as pleomorphic adenoma, the most common benign neoplasm of the minor salivary glands,1 was excised with a limited resection at the age of 19. She remained asymptomatic in the intervening 35 years. Incisional biopsy of the lump confirmed recurrent pleomorphic adenoma. Because the tumor was recurrent, magnetic resonance imaging was performed (Fig 1), which revealed a 3 cm lesion arising from the palate appearing to invade and involve the maxillary antrum. A diagnosis of recurrent benign pleomorphic adenoma was made. Only 1 previous recurrence of pleomorphic adenoma after more than 30 years has been noted in the literature.2 Excision was performed which involved a right sided partial posterior maxillectomy and immediate reconstruction with a temporalis flap. Subsequent histology confirmed complete excision of recurrent pleomorphic adenoma with adequate surgical margins. One year after surgery the palate had
1. Spiro RH: Salivary neoplasms: Overview of a 35 year experience with 2807 patients. Head Neck Surg 8:177, 1986 2. Yasumoto M, Sunaba K, Shibuya H, et al: Recurrent pleomorphic adenoma of the head and neck. Neuroradiology 41:300, 1999
doi:10.1016/j.joms.2006.05.012
BISPHOSPHONATE-ASSOCIATED OSTEONECROSIS (BON) OF THE JAWS: A POSSIBLE TREATMENT? To the Editor:—Management of bisphosphonate-associated osteonecrosis (BON) of the jaws is currently a very topical subject. At present, there is no effective treatment for this condition. Several authors have recommended that prevention, when possible, of BON in patients at risk is the gold standard. In established cases, bisphosphonate therapy should not be discontinued; aggressive surgery of bone defects is mostly counterproductive, and furthermore, hyperbaric oxygen is of no benefit to patients affected with BON. In accordance with these restrictive therapy guidelines, the conclusion has been that these patients must and can live with some exposed bone in the oral cavity.1-3 Intermittent or continuous antibiotic therapy (penicillin V-K 500 mg, 4 times daily in association with metronidazole 500 mg, 3 times daily) has been shown to be beneficial as symptomatic treatment.1,2 However, bisphosphonates are commonly prescribed (both intravenously and orally) for a range of conditions including osteoporosis, Paget’s disease, multiple myeloma, hypercalcemia of malignancy, and bone metastases of malignancies (such as breast and prostate
1461
LETTERS TO THE EDITOR
FIGURE 1. BON of the mandible.
cancer). Therefore, patients receiving these drugs are characterized by different systemic metabolic conditions, life expectancy, and ability to bear the side effects of these prolonged (and sometimes permanent) therapeutic antibiotic schemes. In addition, patients affected by BON of the jaws often develop recurrence of bone defects, with variable timing, in spite of the antibiotic treatments. Thus, it would be useful to find an alternative treatment of this condition. It is not possible to achieve complete bone radiographic healing or carry out histologic confirmation; and the main goal at the moment in the management of BON is “clinical success.” In practical terms, this means: - No pain and no symptoms of oral infections; - No signs of oral/cutaneous draining fistulas; and - Mucosal healing of exposed bone; with a relief from signs and symptoms in the same area during follow-up. At present, to obtain all of the 3 points previously mentioned is the best clinical success, but this could be considered a partial clinical success even when just 1 of these is achieved for a significant period of time. Low level laser therapy (LLLT; ie, those delivering an output power in the milliwatt range) has a potential antimicrobial and biostimulant effect when applied to oral tissue. Several in vitro and in vivo studies have been carried out to clarify the usefulness of LLLT as a tool for stimulating the proliferation of cells and the healing of wounds. In addition, lymphatic and blood capillaries appear to be stimulated by laser irradiation. Molecular factors, such as light absorption by mitochondrial enzymes, cytochromes, flavins, and porphirins, could also be implied.4
FIGURE 3. Seven-month follow-up: resolution of the BON after surgery and LLLT.
In vitro phototherapy influences cell growth, cell enzyme, and protein production and acts as a proliferative stimulus on osteoblast-like cells, with or without the administration of drugs (such as corticosteroids or antibiotics).5 In addition, it has been reported that the LLLT improves the bone mineralization process in traumatized sites (in particular, the inorganic component), irrespective of whether it is used in association with biomaterials. Moreover, the increase in mineralization during the regenerative bone process after dental implants has been shown as a result of LLLT with an increase in calcium and phosphorous and further confirmed with Raman spectroscopy.6 As a consequence, we have begun to introduce Nd:YAG laser biostimulation (125 W, 15 Hz, 60 seconds for 5 applications, fiber 320 m) as an additional tool in the treatment of BON lesions. Between 2004 and 2006 we examined 26 patients affected by this condition (9 patients affected by multiple myeloma, 14 treated for bone metastases of malignancies, and 3 for severe osteoporosis) who were subdivided into 4 different groups (as a result of developing therapy schemes). Six patients were treated with a surgical approach plus antibiotics, 6 with antibiotics only, 6 with laser biostimulation associated with antibiotics, and 8 with laser biostimulation applied after surgical debridement, removal of necrotic bone, and antibiotic therapy. Of the 14 patients who underwent laser biostimulation, 9 reported complete clinical success (no pain, no symptoms of infections, and neither signs of exposed bone nor draining fistulas) with a follow-up of between 4 to 7 months (Figs 1-3). Two patients improved their symptomatology only. Three patients reported no clinical improvement. Conversely, of the remaining 12 patients where the laser was not used, only 4 had a clinical success and 1 reported no pain, although the exposed bone was still visible in the oral cavity. While these findings are not conclusive, they may be a step forward for improved management of this condition. PAOLO VESCOVI, DDS ELISABETTA MERIGO, DDS MARCO MELETI, DDS MADDALENA MANFREDI, DDS, PHD Parma, Italy
References FIGURE 2. Radiographic vision during the first examination.
1. Marx RE, Sawatari Y, Fortin M, et al: Bisphosphonate-induced exposed bone (osteonecrosis-osteopetrosis) of the jaws: Risk
1462
3.
4.
5. 6.
factors, recognition, prevention and treatment. J Oral Maxillofac Surg 63:1567, 2005 Schwartz HC: Bisphosphonate-associated osteonecrosis of the jaws. J Oral Maxillofac Surg 63:1555, 2005 Merigo E, Manfredi M, Meleti M, et al: Jaw bone necrosis without previous dental extractions associated with the use of bisphosphonates (pamidronate and zoledronate): A four-case report. J Oral Pathol Med 34:613, 2005 Rochkind S, Kogan G, Luger EG, et al: Molecular structure of the bony tissue after experimental trauma to the mandibular region followed by laser therapy. Photomed Laser Surg 22: 249, 2004 Fujihara NA, Hiraki KR, Marques MM: Irradiation at 780 nm increases proliferation rate of osteoblasts independently of dexamethasone presence. Laser Surg Med 38:332, 2006 Khandra M, Ronold HJ, Lyngstaddas SP, et al: Low-level laser therapy stimulates bone implant interaction: An experimental study in rabbits. Clin Oral Implants Res 15:325, 2004
doi:10.1016/j.joms.2006.05.042
PSEUDOCYSTS OF THE MANDIBULAR CONDYLE To the Editor:—The authors of a recently published article (J Oral Maxillofac Surg 64:712-718, 2006)1 described an elderly female patient with breast cancer whose disease metastasized to both the right and left temporomandibular joint apparatus as evidenced by an initial complaint of severe trismus. In the body of the article the authors note that on a panoramic radiograph there “appeared to be a 0.5-cm radiolucency. . . within the left condyle” and the legend for the figure reads “Note the 0.5-cm radiolucency involving the left mandibular condyle.” However, when the authors reviewed the axial computed tomography scans they noted that “a frank radiolucency of the [left] condyle was not revealed.” This diagnostic dilemma was studied by our research group and the results were published in this journal in 1992.2 We concluded that it is critically important for clinicians to recognize that this apparent discrepancy in the imaging findings between panoramic radiography and axial computed tomography relative to the presence of a wellcorticated radiolucency in the “anterior” portion of the head of the condyle results in the production of a “pseudocyst,” which arises from a combination of age-related changes in the head of the condyle and distortion of these changes by the panoramic radiography unit. In older individuals, alterations in occlusion and mandibular function cause a remodeling of the condylar head such that there is greater cupping of the pterygoid fovea (site of insertion of both the inferior and superior heads of the lateral pterygoid muscle) and a remodeling of the medial and lateral ridges of the condyle so that they take on a more defined cortical appearance. Panoramic radiography accentuates and distorts these physiologic changes in mandibular form because the central x-ray beam usually does not pass through the condyle at a right angle, but rather passes obliquely in the horizontal plane and superiorly in the vertical plane. This results in the medial ridge (crest) of the mandibular neck being projected posterior/superiorly and the lateral ridge being projected anterior/inferiorly. These ridges take on the appearance of corticated margins surrounding a “cyst like” radiolucent pterygoid fovea.
References 1. Miles BA, Schwartz-Dabney C, Sinn DP, et al: Bilateral metastatic breast adenocarcinoma within the temporomandibular joint: A case report. J Oral Maxillofac Surg 64:712, 2006 2. Friedlander AH, Monson ML, Friedlander MD, et al: Pseudocysts of the mandibular condyle. J Oral Maxillofac Surg 50:821, 1992
doi:10.1016/j.joms.2006.05.015
DOES SMOKING AFFECT THE SURVIVAL OF MINIPLATES IN THE ORAL AND MAXILLOFACIAL REGION? To the Editor:—Titanium miniplates have been used for osteosynthesis in the oral and maxillofacial region for over 40 years. Most midface and mandibular osteosynthesis is undertaken via an intraoral approach using titanium miniplates for fixation. These plates are not usually removed unless clinically indicated by symptoms encountered at subsequent surgery or on patient request. We have studied the various factors affecting the removal of miniplates from the maxillofacial region for over 4 years.1,2 Smoking has a directly adverse outcome in patients receiving titanium endosseous implants and much work has been done on this subject.3-5 However, we did not find a single reference to the effects of smoking on titanium miniplates. Osteosynthesis is not directly comparable to osseointegration, but the effects of smoking on the oral mucosa and healing may indirectly affect osteosynthesis plates. We returned to our original data (153 patients had plates inserted in the oral and maxillofacial region at the Department of Oral and Maxillofacial Surgery, University Hospital Birmingham [Edgbaston, UK], between November 1, 1998, and November 30, 1999. All 153 patient records were revisited on or after October 31, 2002, giving a minimum follow-up of 3 years and a maximum of 4 years), and we subjected them to Cox regression analysis using the smoking habit as a cofactor alongside age, gender, site, type of operation, and profile of plate. We found no statistically significant difference in plate survival in the smoking and nonsmoking groups, although proportionally greater numbers were removed from smokers (Fig 1). The effects of smoking on titanium endosseous implants are well documented. However, the effect of smoking on
Miniplate Survival Smokers vs Non-smokers Log Rank Statistic = 1.69 (1df, p = 0.1931) 1.00
Cumulative Survival
2.
LETTERS TO THE EDITOR
.98 .96
SMOKING .94 1 .92
1-censored
.90
0 0-censored
.88
ARTHUR H. FRIEDLANDER, DMD MARK MONSON, DDS MARK D. FRIEDLANDER, JD, LLM Sepulveda, CA
0
52
104
156
208
TIME PLATES INSITU (weeks)
FIGURE 1. Miniplate survival: smokers versus nonsmokers.
LETTERS TO THE EDITOR
to present an alternative, successful method for treatment/ elimination of a ranula—which has a notorious history of poor response to surgical care. In the 45 years of my OMFS career I have been privileged to treat these lesions, mostly in young patients, and have had a multiplicity of patient and parental complaints resulting from the technique of packing in regards to postoperative discomfort and the necessity, in my hands, for retreatment. As to the procedure itself: A trapdoor-shaped flap was first outlined so as to permit grasping of its margin to facilitate the final incision for unroofing. The cotton swab inspection of the base was performed to preclude missing an incipient deep extension prior to scarifying the base by defocusing the laser. In truth, however, the swab probably served little purpose in the hands of the parents at home. The successful healing was, I believe, a result of the laserbased treatment itself. While only a 14-day clinical follow-up was available, the lack of any complaint or return to clinic by the patient/ parent in over a year (nor inquiries from other surgeons in the area to whom the patient may have appeared for secondary care), indicated that the treatment was definitive. Finally, with complete absence of postoperative pain or bleeding as reported by the patient/parent, absent the need for any placement or removal of sutures, and with the ability to identify and avoid vital structures in the area as the Waterlase cut through the superficial tissues at a slow, controlled rate, I believe that this modality offers the surgeon a worthwhile addition to his armamentarium. MALCOLM ZOLA, DDS Bronx, NY
FIGURE 1. Coronal MRI highlighting tumor in right palate involving the floor of the maxillary sinus.
healed without event and there was no evidence of recurrence. MARK J.A. TURNER, BDS, MB, BCHIR, MA, FDSRCS, MRCS WILLIAM P. SMITH Northampton, UK
References doi:10.1016/j.joms.2006.06.253
AN EXCEPTIONALLY LATE RECURRENCE OF PLEOMORPHIC ADENOMA To the Editor:—We would like to highlight late recurrence of pleomorphic adenoma of the palate and the importance of warning the patient of the risk. The following case highlights the long latency (35 years) between initial excision and recurrence. A 54-year-old woman was urgently referred by her general dental surgeon with a 3-month history of persistent, painless, slow-growing palatal swelling. Clinical examination revealed a swelling of her palate at the site where 35 years earlier she had undergone an excision biopsy. The primary lesion, histologically confirmed as pleomorphic adenoma, the most common benign neoplasm of the minor salivary glands,1 was excised with a limited resection at the age of 19. She remained asymptomatic in the intervening 35 years. Incisional biopsy of the lump confirmed recurrent pleomorphic adenoma. Because the tumor was recurrent, magnetic resonance imaging was performed (Fig 1), which revealed a 3 cm lesion arising from the palate appearing to invade and involve the maxillary antrum. A diagnosis of recurrent benign pleomorphic adenoma was made. Only 1 previous recurrence of pleomorphic adenoma after more than 30 years has been noted in the literature.2 Excision was performed which involved a right sided partial posterior maxillectomy and immediate reconstruction with a temporalis flap. Subsequent histology confirmed complete excision of recurrent pleomorphic adenoma with adequate surgical margins. One year after surgery the palate had
1. Spiro RH: Salivary neoplasms: Overview of a 35 year experience with 2807 patients. Head Neck Surg 8:177, 1986 2. Yasumoto M, Sunaba K, Shibuya H, et al: Recurrent pleomorphic adenoma of the head and neck. Neuroradiology 41:300, 1999
doi:10.1016/j.joms.2006.05.012
BISPHOSPHONATE-ASSOCIATED OSTEONECROSIS (BON) OF THE JAWS: A POSSIBLE TREATMENT? To the Editor:—Management of bisphosphonate-associated osteonecrosis (BON) of the jaws is currently a very topical subject. At present, there is no effective treatment for this condition. Several authors have recommended that prevention, when possible, of BON in patients at risk is the gold standard. In established cases, bisphosphonate therapy should not be discontinued; aggressive surgery of bone defects is mostly counterproductive, and furthermore, hyperbaric oxygen is of no benefit to patients affected with BON. In accordance with these restrictive therapy guidelines, the conclusion has been that these patients must and can live with some exposed bone in the oral cavity.1-3 Intermittent or continuous antibiotic therapy (penicillin V-K 500 mg, 4 times daily in association with metronidazole 500 mg, 3 times daily) has been shown to be beneficial as symptomatic treatment.1,2 However, bisphosphonates are commonly prescribed (both intravenously and orally) for a range of conditions including osteoporosis, Paget’s disease, multiple myeloma, hypercalcemia of malignancy, and bone metastases of malignancies (such as breast and prostate
1461
LETTERS TO THE EDITOR
FIGURE 1. BON of the mandible.
cancer). Therefore, patients receiving these drugs are characterized by different systemic metabolic conditions, life expectancy, and ability to bear the side effects of these prolonged (and sometimes permanent) therapeutic antibiotic schemes. In addition, patients affected by BON of the jaws often develop recurrence of bone defects, with variable timing, in spite of the antibiotic treatments. Thus, it would be useful to find an alternative treatment of this condition. It is not possible to achieve complete bone radiographic healing or carry out histologic confirmation; and the main goal at the moment in the management of BON is “clinical success.” In practical terms, this means: - No pain and no symptoms of oral infections; - No signs of oral/cutaneous draining fistulas; and - Mucosal healing of exposed bone; with a relief from signs and symptoms in the same area during follow-up. At present, to obtain all of the 3 points previously mentioned is the best clinical success, but this could be considered a partial clinical success even when just 1 of these is achieved for a significant period of time. Low level laser therapy (LLLT; ie, those delivering an output power in the milliwatt range) has a potential antimicrobial and biostimulant effect when applied to oral tissue. Several in vitro and in vivo studies have been carried out to clarify the usefulness of LLLT as a tool for stimulating the proliferation of cells and the healing of wounds. In addition, lymphatic and blood capillaries appear to be stimulated by laser irradiation. Molecular factors, such as light absorption by mitochondrial enzymes, cytochromes, flavins, and porphirins, could also be implied.4
FIGURE 3. Seven-month follow-up: resolution of the BON after surgery and LLLT.
In vitro phototherapy influences cell growth, cell enzyme, and protein production and acts as a proliferative stimulus on osteoblast-like cells, with or without the administration of drugs (such as corticosteroids or antibiotics).5 In addition, it has been reported that the LLLT improves the bone mineralization process in traumatized sites (in particular, the inorganic component), irrespective of whether it is used in association with biomaterials. Moreover, the increase in mineralization during the regenerative bone process after dental implants has been shown as a result of LLLT with an increase in calcium and phosphorous and further confirmed with Raman spectroscopy.6 As a consequence, we have begun to introduce Nd:YAG laser biostimulation (125 W, 15 Hz, 60 seconds for 5 applications, fiber 320 m) as an additional tool in the treatment of BON lesions. Between 2004 and 2006 we examined 26 patients affected by this condition (9 patients affected by multiple myeloma, 14 treated for bone metastases of malignancies, and 3 for severe osteoporosis) who were subdivided into 4 different groups (as a result of developing therapy schemes). Six patients were treated with a surgical approach plus antibiotics, 6 with antibiotics only, 6 with laser biostimulation associated with antibiotics, and 8 with laser biostimulation applied after surgical debridement, removal of necrotic bone, and antibiotic therapy. Of the 14 patients who underwent laser biostimulation, 9 reported complete clinical success (no pain, no symptoms of infections, and neither signs of exposed bone nor draining fistulas) with a follow-up of between 4 to 7 months (Figs 1-3). Two patients improved their symptomatology only. Three patients reported no clinical improvement. Conversely, of the remaining 12 patients where the laser was not used, only 4 had a clinical success and 1 reported no pain, although the exposed bone was still visible in the oral cavity. While these findings are not conclusive, they may be a step forward for improved management of this condition. PAOLO VESCOVI, DDS ELISABETTA MERIGO, DDS MARCO MELETI, DDS MADDALENA MANFREDI, DDS, PHD Parma, Italy
References FIGURE 2. Radiographic vision during the first examination.
1. Marx RE, Sawatari Y, Fortin M, et al: Bisphosphonate-induced exposed bone (osteonecrosis-osteopetrosis) of the jaws: Risk
1462
3.
4.
5. 6.
factors, recognition, prevention and treatment. J Oral Maxillofac Surg 63:1567, 2005 Schwartz HC: Bisphosphonate-associated osteonecrosis of the jaws. J Oral Maxillofac Surg 63:1555, 2005 Merigo E, Manfredi M, Meleti M, et al: Jaw bone necrosis without previous dental extractions associated with the use of bisphosphonates (pamidronate and zoledronate): A four-case report. J Oral Pathol Med 34:613, 2005 Rochkind S, Kogan G, Luger EG, et al: Molecular structure of the bony tissue after experimental trauma to the mandibular region followed by laser therapy. Photomed Laser Surg 22: 249, 2004 Fujihara NA, Hiraki KR, Marques MM: Irradiation at 780 nm increases proliferation rate of osteoblasts independently of dexamethasone presence. Laser Surg Med 38:332, 2006 Khandra M, Ronold HJ, Lyngstaddas SP, et al: Low-level laser therapy stimulates bone implant interaction: An experimental study in rabbits. Clin Oral Implants Res 15:325, 2004
doi:10.1016/j.joms.2006.05.042
PSEUDOCYSTS OF THE MANDIBULAR CONDYLE To the Editor:—The authors of a recently published article (J Oral Maxillofac Surg 64:712-718, 2006)1 described an elderly female patient with breast cancer whose disease metastasized to both the right and left temporomandibular joint apparatus as evidenced by an initial complaint of severe trismus. In the body of the article the authors note that on a panoramic radiograph there “appeared to be a 0.5-cm radiolucency. . . within the left condyle” and the legend for the figure reads “Note the 0.5-cm radiolucency involving the left mandibular condyle.” However, when the authors reviewed the axial computed tomography scans they noted that “a frank radiolucency of the [left] condyle was not revealed.” This diagnostic dilemma was studied by our research group and the results were published in this journal in 1992.2 We concluded that it is critically important for clinicians to recognize that this apparent discrepancy in the imaging findings between panoramic radiography and axial computed tomography relative to the presence of a wellcorticated radiolucency in the “anterior” portion of the head of the condyle results in the production of a “pseudocyst,” which arises from a combination of age-related changes in the head of the condyle and distortion of these changes by the panoramic radiography unit. In older individuals, alterations in occlusion and mandibular function cause a remodeling of the condylar head such that there is greater cupping of the pterygoid fovea (site of insertion of both the inferior and superior heads of the lateral pterygoid muscle) and a remodeling of the medial and lateral ridges of the condyle so that they take on a more defined cortical appearance. Panoramic radiography accentuates and distorts these physiologic changes in mandibular form because the central x-ray beam usually does not pass through the condyle at a right angle, but rather passes obliquely in the horizontal plane and superiorly in the vertical plane. This results in the medial ridge (crest) of the mandibular neck being projected posterior/superiorly and the lateral ridge being projected anterior/inferiorly. These ridges take on the appearance of corticated margins surrounding a “cyst like” radiolucent pterygoid fovea.
References 1. Miles BA, Schwartz-Dabney C, Sinn DP, et al: Bilateral metastatic breast adenocarcinoma within the temporomandibular joint: A case report. J Oral Maxillofac Surg 64:712, 2006 2. Friedlander AH, Monson ML, Friedlander MD, et al: Pseudocysts of the mandibular condyle. J Oral Maxillofac Surg 50:821, 1992
doi:10.1016/j.joms.2006.05.015
DOES SMOKING AFFECT THE SURVIVAL OF MINIPLATES IN THE ORAL AND MAXILLOFACIAL REGION? To the Editor:—Titanium miniplates have been used for osteosynthesis in the oral and maxillofacial region for over 40 years. Most midface and mandibular osteosynthesis is undertaken via an intraoral approach using titanium miniplates for fixation. These plates are not usually removed unless clinically indicated by symptoms encountered at subsequent surgery or on patient request. We have studied the various factors affecting the removal of miniplates from the maxillofacial region for over 4 years.1,2 Smoking has a directly adverse outcome in patients receiving titanium endosseous implants and much work has been done on this subject.3-5 However, we did not find a single reference to the effects of smoking on titanium miniplates. Osteosynthesis is not directly comparable to osseointegration, but the effects of smoking on the oral mucosa and healing may indirectly affect osteosynthesis plates. We returned to our original data (153 patients had plates inserted in the oral and maxillofacial region at the Department of Oral and Maxillofacial Surgery, University Hospital Birmingham [Edgbaston, UK], between November 1, 1998, and November 30, 1999. All 153 patient records were revisited on or after October 31, 2002, giving a minimum follow-up of 3 years and a maximum of 4 years), and we subjected them to Cox regression analysis using the smoking habit as a cofactor alongside age, gender, site, type of operation, and profile of plate. We found no statistically significant difference in plate survival in the smoking and nonsmoking groups, although proportionally greater numbers were removed from smokers (Fig 1). The effects of smoking on titanium endosseous implants are well documented. However, the effect of smoking on
Miniplate Survival Smokers vs Non-smokers Log Rank Statistic = 1.69 (1df, p = 0.1931) 1.00
Cumulative Survival
2.
LETTERS TO THE EDITOR
.98 .96
SMOKING .94 1 .92
1-censored
.90
0 0-censored
.88
ARTHUR H. FRIEDLANDER, DMD MARK MONSON, DDS MARK D. FRIEDLANDER, JD, LLM Sepulveda, CA
0
52
104
156
208
TIME PLATES INSITU (weeks)
FIGURE 1. Miniplate survival: smokers versus nonsmokers.