Perioperative Unfavorable Fracture in the Sagittal Splitting Ramus Osteotomy and its Management.

Sagittal splitting ramus osteotomy is widely performed for correction of mandibular skeletal dentofacial deformities. W e retrospectively studied 325 patients treated with bilateral sagittal splitting ramus osteotomies in order to investigate perioperative unfavorable fracture, and found eight episodes of fracture in eight patients (2.4% of incidence). The most predominant fracture site was the distal segment with vertical and horizontal fracture line. All fractured segments were sufficiently repositioned and fixed in appropriate positions. Slight extension of the intermaxillary fixation period was noted, however, no severe postoperative complication was found.It was considered that incomplete osteotomy, misdirection of horizontal medial osteotomy, and violent bone split caused unfavorable fractures.