Position of Mandibular Canal and Ramus Morphology Before and After Sagittal Split Ramus Osteotomy

Abstract

Purpose. The purpose of this study was to evaluate changes in the mandibular canal and ramus morphology before and after a sagittal split ramus osteotomy (SSRO). Results. Postoperative ramus width, lateral distance, lateral marrow distance and canal length were significantly larger than the pre-operative values, at the foramen, 1cm lower and 2 cm lower levels. The mandibular canal completely contacted the lateral cortex without lateral bone marrow in 6 sides (10%) in level A and B, and 4 sides (6.7%) in level C pre-operatively and 6 sides (10%) in level C post-operatively. Subjects andConclusion. This study suggested that postoperative mandibular canal position was located more posteriorly and the postoperative lateral bone marrow became thicker compared to the pre-operative state.

Postoperative Positional and Dimensional Changes of Mandibular Canal after Bilateral Sagittal Split Set-Back Osteotomy

“…SimPlant Pro Standalone 13.0 soft- ware used in this study and the other visualization programs allow us to perform measurements on cross-sectional slices, which have been described as the most reliable slices (19). These slices are reported be uninfluenced by the obliquity in the images (15,17).…”

“…Although we found similar results, personal variations and slicing variation may affect millimetric measurements. Thus, millimetric measurements are not reliable, except when choosing the correct size of the fixation screws in order to prevent IAN injury (17).…”

“…Because of this limitation, many authors used 3D imaging techniques despite high doses and prices. (6,8,11,(15)(16)(17)(18). Yamamoto et al (15) determined the location of MC on predefined slices and showed an increased risk of IAND when MC is in contact with external cortical bone of the mandible.…”

Position of mandibular canal and ramus morphology after sagittal split ramus osteotomy

“…Ueki [18] conducted a study on 30 patients (60 sides) with mandibular prognathism for locating the MC position and ramus morphology before and after BSSO; they used computed tomographic scan, and the position of the canal and ramus morphology were measured at three horizontal planes: at the mandibular foramen level (level A), 1 cm lower than level A (level B), and 2 cm lower than level A (level C). Thereafter, the MC and ramus morphology were measured preoperatively and postoperatively.…”

Osteossíntese no Tratamento Cirúrgico dos Prognatismos: Estado da Arte

“…Os parafusos monocorticais também não são isentos de risco, porque a anatomia do canal mandibular é variável, havendo uma percentagem significativa de indivíduos, entre 6% -25%, que apresenta uma distância diminuta entre o nervo e o córtex bucal. 23,[26][27][28][29] A incidência desta complicação na OSR, seja para recuo ou avanço mandibular, é muito variável, 21 o que se deve possivelmente à falta de um método padronizado de avaliação da função sensitiva do nervo. 30 Por via de um questionário, mas sem avaliação objetiva concomitante, um grupo verificou uma prevalência de alterações sensitivas de 40% aos quatro a nove anos após OSR de recuo estabilizada com três parafusos bicorticais.…”