RESUMO
La osteotomía sagital de rama mandibular bilateral, es un procedimiento que se considera seguro, predecible y estable utilizado para corregir las anomalías dentofaciales de origen esquelético únicas o en combinación con otras osteotomías faciales. La fijación de los segmentos osteotomizados se realiza mediante el uso de material de osteosíntesis no reabsorbible de material tipo titanio, en su mayoría con tornillos bicorticales de longitudes mayores con respecto a los tornillos convencionales utilizados para fijación rígida ósea facial, sin embargo en algunos casos, la oclusión definitiva posterior a la cirugía ortognatica no es similar al planeamiento prequirúrgico planeado, debido a factores asociados a la fijación rígida con tornillos bicorticales, Se ha observado en una amplia cantidad de osteotomías sagitales bilaterales de rama mandibular durante la fijación con tornillos bicorticales, movimientos de tipo indeseado por el operador, a menudo observando máxima intercuspidacion en la zona posterior derecha y leve mordida abierta en la zona posterior izquierda; de acuerdo a la biomecánica mandibular dichos movimientos ocurren por la presencia del eje de la rosca de los tornillos bicorticales utilizados para la fijación rígida que en su mayoría están dirigidos en sentido de las agujas del reloj. El propósito de este artículo es proponer el uso de tornillos bicorticales de rosca invertida para la fijación de la osteotomía sagital mandibular contrarrestando el efecto indeseado observado en la oclusión definitiva de pacientes sometidos a osteotomías sagitales bilaterales de rama mandibular, en paciente sometidos a cirugía ortognatica monomaxilar y bimaxilar para la corrección de anomalías dentofaciales.
The bilateral sagittal ramus osteotomy is a procedure that is considered safe, predictable and stable dentofacial used to correct skeletal abnormalities unique origin or in combination with other facial osteotomies. Osteotomized fixing segments is performed using non-resorbable osteosynthesis material type titanium material, mostly bicortical screws with longer lengths compared to conventional screws used for rigid fixation facial bone, however in some cases, the subsequent final occlusion orthognathic surgery is not similar to preoperative planning planned due to factors associated with rigid fixation with bicortical screws, it has been observed in a wide number of bilateral sagittal osteotomy of ramus during fixation with bicortical screws movements unwanted by the operator type, often observing maximum intercuspation in the right posterior open bite and mild in the left rear area; according to the mandibular biomechanics such movements occur by the presence of the thread axis of the bicortical screws used for rigid fixation which mostly are directed in the direction of clockwise. It is the purpose of this review article, proposing the use of bicortical screws reverse threaded for fixing the mandibular sagittal osteotomy counteracting the undesirable effect observed in the final occlusion patients undergoing bilateral sagittal osteotomy of ramus in patients undergoing surgery monomaxilar bimaxillary orthognathic and for the correction of dentofacial anomalies.
RESUMO
A modified pendulum appliance with 2 endosseus screws for anchorage in the palatal area was used for maxillary molar distalization in each of 15 patients (average age, 13 +/- 2.1 years). Study models and lateral and panoramic x-rays were taken at the beginning and end of the movement to record the dental and skeletal changes. The mean treatment time was 7.8 +/- 1.7 months, the average distal movement of the maxillary molars was 6 mm, and the inclination was 11.3 degrees +/- 6.2 degrees. The second premolars were distalized an average of 4.85 +/- 1.96 mm with inclinations of 8.6 degrees +/- 5 degrees. The maxillary anterior teeth were retruded 0.5 +/- 1.33 mm and palatally inclined 2.5 degrees +/- 2.98 degrees. The mandibular plane rotated posteriorly 1.27 degrees +/- 1.1 degrees. No loss of dental anchorage was observed during the distal movement.