Aim of the study was to evaluate the change in position of mandibular canal and ramus morphology before and after bilateral sagittal split ramus osteotomy. Patients and methods This study was conducted on 6 patients (12 sides) with either retrognathism or prognathism using CBCT to evaluate the change in position of mandibular canal (MC), after sagittal split ramus osteotomy for either mandibular advancement or set back, in 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 done using axial cuts after fusion between the pre- and post-operative radiographs at three levels after dividing the skull from the roof of the orbit till the inferior border of the chin to 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 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 increasing of ramus width, while it moved inferiorly in class III without changes in ramus morphology postoperatively.