Aim of the study: The aim of the study was to evaluate the change in position of mandibular canal (MC) and ramus morphology before and after bilateral sagittal split ramus osteotomy.
Patients and methods: This study was conducted on six patients (12 sides) with either retrognathism or prognathism using cone beam computed tomograms to evaluate the change in position of MC after sagittal split ramus osteotomy for either mandibular advancement or setback at three levels of coronal cuts – namely lateral orbital rim (level 1), lateral malar bone (level 2), and anterior rim of the ramus (level 3) – at 6 months postoperatively. Evaluation of ramus morphology was carried out using axial cuts after fusion between the preoperative and postoperative radiographs at three levels after dividing the skull from the roof of the orbit to the inferior border of the chin into 14 cuts to choose cut number 4 as level 4, cut number 5 as level 5 and cut number 6 as level 6.
Results: In class II, the MC was located more superiorly and there was an increase in ramus width postoperatively, whereas in class III the MC was located more inferiorly postoperatively.
Conclusion: The MC in class II was moved superiorly postoperatively with an increase in ramus width, whereas it was moved inferiorly in class III without changes in ramus morphology postoperatively.