Changes in condylar position after BSSRO with and without Le Fort I osteotomy via surgery-first approach in mandibular prognathism with facial asymmetry

Abstract

This study aimed to evaluate changes in condylar position after bilateral sagittal split ramus osteotomy (BSSRO) with and without Le Fort I osteotomy via the surgery-first approach (SFA) in patients with facial asymmetry. Eighteen patients (36 condyles) who received surgical-orthodontic treatment using the SFA were included and divided into 2 groups depending on the extent of surgery: BSSRO-only group (n=12) and BSSRO with Le Fort I osteotomy group (n=6). Using computed tomography images taken preoperatively, immediately postoperatively, and 6months postoperatively, surgical and postoperative changes of the condylar position were analyzed 3-dimensionally. Both groups showed mainly inferolateral displacement with inward rotation immediately after surgery, and superomedial returning movement with outward rotation 6months after surgery. There was no statistical difference in time-course changes of the condylar position between the 2 groups. In comparing the deviated and nondeviated sides, the deviated side showed significantly greater amount of bodily shift and rotational movement after surgery compared with the nondeviated side in both groups. These results suggest that BSSRO via the SFA, either with or without Le Fort I osteotomy, may cause condylar displacement after surgery and that the displaced condyles return to their original position on both the deviated and the nondeviated sides.