Medial cortex fracture patterns after sagittal split osteotomy using short versus long medial cuts: can we obviate bad splits?

The aim of the present study was to evaluate the lingual fracture patterns after sagittal split osteotomy (SSO) using short and long medial osteotomy cuts, via three-dimensional (3D) cone beam computed tomography (CBCT). Forty-six subjects participated in this prospective study. Two types of medial osteotomy line were made: for type I, the medial osteotomy line was finished just before the lingula; for type II, the medial osteotomy line was extended 3-4mm beyond the lingula. Three fracture patterns were observed after SSOs. There were no significant differences in the medial fracture patterns between the two medial osteotomy types (P=0.16). The buccolingual thickness of the ramus was lower in fractures with pattern 3 (bad split) than in the two other fracture patterns. The length of the medial osteotomy line - short or long - did not alter the prevalence of a bad split. The bone thickness of the ramus may affect the type of fracture pattern on the medial side of the ramus.