Minimizing displacement of the proximal segment after bilateral sagittal split ramus osteotomy in asymmetric cases

Purpose: This study evaluated a modified sagittal split ramus osteotomy designed to minimize displacement of the proximal segmentation asymmetric cases. Patients and Methods: Nine patients with facial asymmetry were corrected with modified bilateral sagittal split ramus osteotomy from November 1992 to February 1999. Preoperative and 3-month postoperative anteroposterior (AP) radiographs were traced and compared. The angle of mandibular rotation of the proximal segments was obtained by measuring the intersection of lines passing through the upper rim of the orbit and the lateral border of the proximal segment. The condition of the temporomandibular joint (TMJ) was evaluated clinically by measuring the interincisal distance and looking for any untoward symptoms. Results: The data showed an average 1.94 degrees +/- 1.18 degrees difference between the preoperative and postoperative condition and no clinical signs of TMJ symptoms. These findings support the use of this procedure for treating asymmetric mandibles. (C) 2001 American Association of Oral and Maxillofacial Surgeons.