Condylar Positional Changes Following Manual Proximal Segment Positioning During Bilateral Sagittal Split Ramus...

Background and Objectives: Maintenance of condylar position during bilateral sagittal split ramus osteotomy (BSSRO) is important for preserving temporomandibular joint biomechanics and skeletal stability. During surgery, loss of muscle tone under general anesthesia may alter the condyle-fossa relationship, making accurate repositioning of the proximal segment challenging. Although manual positioning remains the most commonly used intraoperative approach, evidence regarding its ability to preserve the preoperative condyle-fossa relationship remains limited. This study evaluated changes in the condyle-fossa relationship following BSSRO performed with manual proximal segment positioning. Materials and Methods: This single-center retrospective study included lateral cephalometric radiographs of 14 patients (8 females, 6 males; aged 19-29 years) with skeletal Class III malocclusion treated with combined orthodontic treatment and BSSRO. Radiographs were obtained preoperatively (T0), immediately postoperatively (T1), and at the final follow-up examination (T2). Condylar position was assessed using a Cartesian coordinate system, joint space measurements, and the Condyle Position Index (CPI). Statistical analyses were performed using the Friedman and Wilcoxon signed-rank tests (p < 0.05). Results: Significant differences were observed in CPI and anterior joint space measurements across the observation periods. Interval analysis demonstrated increased CPI values and decreased anterior joint space measurements between T1 and T2, whereas no significant immediate postoperative changes were observed. Intra-observer reliability was excellent, with intraclass correlation coefficients exceeding 0.90 for all variables. Conclusions: Manual positioning of the proximal segment during BSSRO may provide acceptable immediate postoperative condyle-fossa stability but may not completely maintain the preoperative condyle-fossa relationship over time. Although no significant immediate postoperative changes were observed, significant changes in the condyle-fossa relationship were identified at the final follow-up examination. These findings support the need for further prospective studies incorporating clinical temporomandibular joint assessment and three-dimensional imaging.