Valdir Cabral Andrade

Late Mandibular Angle Fracture After Impacted Third Molar Extraction: Case Report and Review of Predisposing Factors

Third molar surgery is the most common surgical procedure in the oral cavity. Whenever extraction is indicated, careful planning based on clinical and radiographic examinations is essential to guard against postoperative complications like: bleeding, alveolitis, infections, injury to adjacent teeth, oroantral communications, or even mandibular fractures. Although rare, the risk of postoperative mandibular fractures after third molar impaction surgery is related to some factors. Our case report a 50-year-old white female patient with a complaint of pain in the region of the left mandibular angle and stated that three weeks before she had the left mandibular third molar extracted, which computerized tomographic confirmed the presence of a fracture in the mandibular angle. However, our report contributes to showing the predisposing factors to cause this injury after a review of the literature, showing the clinician what they should take like consideration when they indicate the extraction of third molars. To avoid this complication, factors like bony impaction, depth of tooth within bone, proximity to the inferior dental canal, tooth position in relation to adjacent teeth, the presence of root dilacerations and others must be taken into account. A case of late mandibular fracture that occurred 21 days after third molar extraction is reported. Conservative treatment was adopted and after six-months of radiographic and clinical follow-up, the patient had fully preserved mandibular function, normal occlusion and no discomfort. ˚

An in vitro comparison between two different designs of sagittal split ramus osteotomy.

Objectives To evaluate the influence of the type of osteotomy in the inferior aspect of the mandible on the mechanical performance. Materials and Methods The study was performed on 20 polyurethane hemimandibles. A sagittal split ramus osteotomy (SSRO) was designed in 10 hemimandibles (group 1) with a vertical osteotomy in the buccal side (second molar level) and final osteotomy was performed horizontally on the lingual aspect, while the mandible body osteotomy was finalized as a straight osteotomy in the basilar area, perpendicular to the body. For group 2, the same osteotomy technique was used, but an oblique osteotomy was done in the basilar aspect of the mandibular body, forming continuity with the sagittal cut in the basilar area. Using a surgical guide, osteosynthesis was performed with bicortical screws using an inverted L scheme. In both groups vertical compression tests were performed with a linear load of 1 mm/min on the central fossa of the first molar and tests were done with models made from photoelastic resin. Data were analyzed using Students t-test, establishing a statistical significance when P <0.05. Results A statistical difference was not observed in the maximum displacements obtained in the two osteotomies (P <0.05). In the extensiometric analysis, statistically significant differences were identified only in the middle screw of the fixation. The photoelastic resin models showed force dissipation towards the inferior aspect of the mandible in both SSRO models. Conclusion We found that osteotomy of the inferior aspect did not influence the mechanical performance for osteosynthesis with an inverted L system.

Osteotomía Sagital de Rama Mandibular con Osteosíntesis en L Invertido: Estudio Mecánico con Fotoelasticidad

El objetivo de esta investigacion es identificar las tensiones presentes en tornillos de osteosintesis utilizados en la fijacion de la osteotomia sagital de rama mandibular (OSRM). Se utilizaron dos modelos de OSRM realizados con resina fotoelastica donde el grupo 1 presentaba una osteotomia basilar recta mientras que el grupo 2 presentaba una osteotomia basilar angulada; en ambos se utilizo el sistema de L invertido para la osteosintesis con tornillos 2.0 de 13 mm de longitud. Posteriormente el sistema fue instalado en un pilar sobre la maquina Instrom, donde se aplico una carga vertical de 1 mm/minuto hasta conseguir el desplazamiento de 3 mm; el punto de carga estuvo en la fosa central del primer molar. La distribucion de franjas mostro mayor tension en el tornillo mas proximo de la osteotomia en ambos grupos; en el grupo 2 se produjo una diseminacion de fuerzas levemente hacia la basilar y en el grupo 1 se mantuvo la diseminacion a traves de la linea oblicua. Se puede concluir que ambas osteotomias mandibulares son eficientes en la distribucion de cargas y que no se observan diferencias cualitativas entre tornillos en terminos de cantidad de diseminacion de energia.