How stable is condylar position after bimaxillary orthognathic surgery? A longitudinal CBCT study.

OBJECTIVES: To evaluate tomographic changes in preoperative and postoperative condylar position in patients undergoing orthognathic surgery by analyzing anterior (AJS), superior (SJS), and posterior (PJS) joint spaces. METHODS: This retrospective, longitudinal study analyzed preoperative and postoperative cone-beam computed tomography scans from 20 patients (40 temporomandibular joints) who underwent bimaxillary orthognathic surgery. The AJS, SJS, and PJS were measured bilaterally, and changes over time were assessed using linear mixed-effects models. RESULTS: The sample comprised 10 men and 10 women, with a mean age of 33.3 ± 8.0 years (range: 24-50 years). No statistically significant effect of time was observed for the AJS (β = -0.022 mm; 95% CI: -0.169 to 0.125; p = 0.769) or the SJS (β = 0.070 mm; 95% CI: -0.055 to 0.195; p = 0.274). In contrast, the PJS showed a statistically significant effect of time (β = 0.176 mm; 95% CI: 0.012 to 0.339; p = 0.035), indicating a small postoperative increase. Side and the time × side interaction were not significant for any joint space (p > 0.05). CONCLUSION: Orthognathic surgery did not produce significant changes in the AJS or SJS. However, it was associated with a statistically significant increase in the PJS during the postoperative period. These findings demonstrate the importance of postoperative monitoring of condylar position in patients undergoing orthognathic surgery.