Search

Purpose The fixation of combined mandibular fractures, especially symphyseal-condylar fractures, although occurring commonly and having a higher complication rate in the clinic, is rarely investigated regarding predictable therapeutic approaches. Thus this study's aim was to assess different forms of condylar fixation when combined with symphyseal fracture fixation. Materials and Methods Using finite element models, we analyzed the stress distribution that occurs when a condylar fracture is fixed with 1 miniplate, 2 miniplates, or a trapezoidal condylar miniplate and when a symphyseal fracture is fixed with 2 parallel plates, 2 perpendicular plates, or 2 lag screws. The null hypothesis was that there would be no differences among the different fixation techniques. Results The results showed a stress concentration in the anterior region of the condyle, close to the sigmoid notch. Moreover, adequate fixation in the symphysis could result in less tension at the condylar region. Therefore, when the symphysis was fixed with a lag-screw technique, condylar fixation was less required, showing a more adequate stress distribution when the condyle was fixed with 1 or 2 plates. Conversely, when the symphyseal fixation was less effective, by use of perpendicular plates, there was a change in the stress distribution at the condylar region, altering fixation behavior and resulting in more tension and displacement in the condyle, especially when a trapezoidal plate was used. Conclusions A lag screw and parallel double plates appear to be suitable for symphyseal fixation, whereas 2 straightly positioned plates and a trapezoidal plate are suitable for condylar fixation. However, the combination of perpendicular plates in symphyseal fixation and a trapezoidal plate in condylar fixation showed an altered stress distribution.

Purpose This in vitro investigation was developed with the purpose of comparing the biomechanical features of 3 different methods of rigid internal fixation for sagittal split ramus osteotomies for mandibular advancement. Materials and Methods Rigid internal fixation techniques included a 4-hole plate and 4 monocortical screws (miniplate group), a 4-hole plate and 4 monocortical screws with 1 additional bicortical positional screw (hybrid group), and 3 bicortical positional screws in a traditional inverted-L pattern (inverted-L group). Screws and miniplates were made of titanium and from a 2.0-mm system (MDT, Rio Claro, SP, Brazil). Sixty polyurethane replicas of human hemimandibles (Nacional, Jau, SP, Brazil) were used as substrates, simulating a 5-mm advancement surgery by a sagittal split ramus osteotomy. They were adapted to a test support, and were submitted to lateral torsional forces on the buccal molar surface and vertical cantilever loading on the incisal edge by an Instron 4411 mechanical testing unit (Instron, Norwood, MA) for recording peak loading at 1 mm, 3 mm, 5 mm, and 10 mm of displacement. Each group was formed by 10 replicas, subjected to a linear noncyclical testing only once. Means and standard deviation were analyzed using analysis of variance and Tukey tests, with a 5% level of significance. Testing failures were also recorded. Results The miniplate group showed lowest load peak scores (P < .01) when compared with the other fixation techniques, irrespective of the direction of force. The inverted-L group showed higher resistance (P < .01) than the hybrid group when vertical forces were applied. For molar load, the hybrid and inverted-L groups showed no significant difference. Conclusions For mandibular advancement surgery of 5 mm, it was concluded that the rigid internal fixation technique for sagittal split ramus osteotomies based on 3 bicortical screws in the inverted-L pattern was the most stable in a laboratory environment. Furthermore, the results suggested that installation of a bicortical positional screw in the retromolar region may significantly optimize the resistance of the miniplate and monocortical screw fixation.

Purpose The correction of maxillomandibular deformities may require maxillary osteotomy procedures that usually present low rates of postoperative complications, such as maxillary sinusitis. The present study evaluated the incidence of maxillary sinusitis after Le Fort I osteotomy in 21 adult patients who underwent maxillary surgery (Le Fort I osteotomy) or bimaxillary surgery (Le Fort I osteotomy plus sagittal mandibular osteotomies) for correction of dentofacial deformities. Patients and Methods Verification of the presence of maxillary sinusitis was assessed through a brief questionnaire, x-rays (Waters views), and nasal endoscopy before surgery and 6 to 8 months after surgery. Results Analysis of results showed an incidence of 4.76% of maxillary sinusitis as a postoperative complication in the studied population. Conclusion Symptomatic patients with a positive radiographic finding or an increased risk for postoperative sinusitis will benefit from endoscopic evaluation to aid in treatment planning and follow-up.

This in vitro investigation was developed with the purpose of comparing the biomechanical features of 3 different methods of rigid internal fixation for sagittal split ramus osteotomies for mandibular advancement.Rigid internal fixation techniques included a 4-hole plate and 4 monocortical screws (miniplate group), a 4-hole plate and 4 monocortical screws with 1 additional bicortical positional screw (hybrid group), and 3 bicortical positional screws in a traditional inverted-L pattern (inverted-L group). Screws and miniplates were made of titanium and from a 2.0-mm system (MDT, Rio Claro, SP, Brazil). Sixty polyurethane replicas of human hemimandibles (Nacional, Jaú, SP, Brazil) were used as substrates, simulating a 5-mm advancement surgery by a sagittal split ramus osteotomy. They were adapted to a test support, and were submitted to lateral torsional forces on the buccal molar surface and vertical cantilever loading on the incisal edge by an Instron 4411 mechanical testing unit (Instron, Norwood, MA) for recording peak loading at 1 mm, 3 mm, 5 mm, and 10 mm of displacement. Each group was formed by 10 replicas, subjected to a linear noncyclical testing only once. Means and standard deviation were analyzed using analysis of variance and Tukey tests, with a 5% level of significance. Testing failures were also recorded.The miniplate group showed lowest load peak scores (P.01) when compared with the other fixation techniques, irrespective of the direction of force. The inverted-L group showed higher resistance (P.01) than the hybrid group when vertical forces were applied. For molar load, the hybrid and inverted-L groups showed no significant difference.For mandibular advancement surgery of 5 mm, it was concluded that the rigid internal fixation technique for sagittal split ramus osteotomies based on 3 bicortical screws in the inverted-L pattern was the most stable in a laboratory environment. Furthermore, the results suggested that installation of a bicortical positional screw in the retromolar region may significantly optimize the resistance of the miniplate and monocortical screw fixation.

Purpose This retrospective study reviewed cases of fractures of the mandibular angle to identify personal data, social traits, fracture characteristics, treatment modalities, and postoperative complications. Patients and Methods From April 1999 until July 2004, 114 patients were treated for 115 fractures of the mandibular angle by the Division of Oral and Maxillofacial Surgery at Piracicaba Dental School-Unicamp, in Brazil. Results More angle fractures were observed in Caucasian (55%) men (89%) with some kind of drug addiction (62%). Patient mean age was 27 years. The majority of fractures in this study were sustained in altercations, including gunshot wounds (43%), followed by vehicle accidents, including bicycles and being struck by a car (39%). Open fractures were the most frequent (90%), with prevalence of the left side (57%). Only 1 patient sustained bilateral angle fractures. Ninety-seven patients (85%) underwent open reduction. Complications occurred in 19 patients (17%); 10 (9%) were infections. Of the total number of complications, 3 underwent another surgical intervention for refixation. The factors that contributed to the development of postoperative complications were social risks that included alcohol abuse, smoking, and intravenous and nonintravenous drug abuse. Conclusions Angle fracture management outcomes are affected by many factors beyond method of fixation.

Purpose A prospective radiographic study analyzed condylar position in patients who had undergone orthodontic treatment and isolated maxillary advancement after Le Fort I osteotomy. Patients and Methods Eleven patients were selected and radiographic images were taken in the immediate preoperative, immediate postoperative (1-2 weeks), and late postoperative periods (minimum of 6 months). Tracings were done on acetate paper for the submento-vertex radiograph, to measure the axial angulation of the condyles, and for the tomographic images of both sides, in the maximal intercuspation, rest position, and maximal opening, for the 3 periods. Linear measurements were taken for the tomograms over the posterior, superior, and anterior articular spaces. These images with the tracings were digitized and measured by means of computer software (UTHSCSA Image Tool 3.0; University of Texas Health Science Center at San Antonio, San Antonio, TX), after it had been adequately calibrated. Results The analysis of variance (ANOVA; 5% of significance) demonstrated 1 ) that there was no statistically significant difference for the linear measurements of the articular spaces in any of the periods, and 2 ) also not for the angular measure of the condyles ( P > .05). In the maximal opening, there was a significant difference for the immediate postoperative period for both sides ( P = .003). Conclusion Le Fort I osteotomy for maxillary advancement did not cause any significant changes in this specific group of patients evaluated.

Purpose The purpose of this report was to review and analyze the epidemiologic features of traumatic subcutaneous emphysema (TSE) originating from frontal, nasoethmoidal, and maxillary facial injuries with sinusal involvement in the emergency room setting. Patients and Methods All patients with a fracture involving the paranasal sinuses were evaluated with regard to TSE occurrence. Data analysis extended to gender, age, etiology, fracture sites, TSE location, sinus involvement, treatment, and complications from April 1999 to December 2003. Evaluation methods included computed tomography scan and clinical evaluation. Results A total of 390 patients sustaining 458 paranasal sinus fractures were included. TSE was observed in 29 patients (7.43%) patients (male-female ratio of 3.83:1, with a mean age of 36.71 ± 15.71 years). The main etiologies were vehicle accidents and assaults. Isolated maxillary sinuses fractures were found in 17 cases (58.62%). Ethmoidal and maxillary fractures were associated with 9 cases (31.03%), and 1 (3.45%) case had maxillary and frontal fractures together. Ethmoidal, maxillary, and frontal fractures were found concomitantly in 2 (6.90%) cases. Periorbital emphysema was the most prevalent site of presentation, and edema (86.21%) and bone deformities (79.31%) were the most frequent findings associated with TSE. Conservative treatment was the prevalent treatment choice (55.17%), and 1 complication because of persistent pain was noted. Conclusion The results suggest that TSE of the face associated with paranasal sinus fractures maintained the clinical features of its fractures of origin. The ethmoidal sinuses were considered as the most prevalent etiologic site, and the periorbital region was responsible for addressing the higher incidence of SE following paranasal sinus fractures.

This retrospective study analyzed the relationship between complications and substance abuse following mandibular fracture. Over a 2-year period, the records of 352 patients with 589 mandibular fractures were reviewed for methods of treatment and other variables, including chronic abuse of drugs. An overall complication rate of 18.5% was found. Positive associations between complications and chronic abuse of alcohol and nonintravenous and intravenous drugs were found. Intravenous drug abusers had a 30%, nonintravenous drug abusers had a 19%, and chronic alcohol abusers had a 15.5% incidence of complications. Those individuals who did not use any drug chronically had a 6.2% complication rate. The results of this study show that chronic substance abuse can significantly affect treatment outcomes for management of mandibular fractures.

Statement of the Problem: The purpose of this study was review, during a five-year period, the zygomaticorbital complex and zygomatic arch fractures treated by the Division of Oral and Maxillofacial Surgery of Piracicaba Dental School, Unicamp, Brazil. Materials and Methods: The age and sex distribution, anatomical types of fractures, associated maxillofacial and nonmaxillofacial trauma, and causes of injuries were described. One thousand eight hundred and fifty seven patients with oral and maxillofacial trauma were evaluated from April 1999 to March 2004. Method of Data Analysis: A description of retrospective chart records analysis. Results: A total of 371 zygomatic-orbital complex and zygomatic arch fractures cases were found in the population. The majority of fractures were sustained by males (82.75%) and whites (56.84%). The age group ranging from 21 to 40 years was most afflicted by zygomatic-orbital complex and zygomatic arch fractures (59.84%). Most patients presented tobacco and alcohol addiction (45.55%) and regular oral hygiene (54.45%). The etiology included falls (21.83%), altercations (19.41%), cyclic accidents (15.63%), car accidents (12.67%), motorcycle accidents (13.48%), sport related accidents (7.82%), and work accidents (3.77%). Isolated zygomatic-orbital complex fractures comprised 266 cases (38.27%) and zygomatic arch fractures 39 cases (10.51%). Additional facial trauma often involved mandible (7.55%), maxilla (5.39%), and nasal (5.12%) fractures. Associated nonmaxillofacial trauma was present in 45.55% of cases, involving upper extremities (61.54%), lower extremities (36.09%), skull (24.85%), thoracic (17.75%), abdominal (5.33%), and neck (4.73%). The treatment of zygomatic-orbital complex and zygomatic arch fractures depended on the type of fracture and the given circumstance. In this study, 56.60% of the patients had no surgical intervention. The complication incidence was 6.20% related mainly with infection (17.39%), hypertrophic scars (8.70%), ectropion (8.70%), and scleral show (8.70%). One patient developed visual deficiency (4.35%). It was noticed most injuries were low-energy trauma, caused by falls and cyclic accidents, involving mainly young adult males. Conclusion: Based on the results, this study gives important epidemiologic data to plan prevention and treatment of maxillofacial trauma of this population at Sao Paulo State, Brazil. References