Three-Dimensional Analysis of Perioperative Condylar Displacement After Mandibular Setback Surgery With Intended Manual Condylar Positioning.

Purpose: The purpose of this study is to investigate the effect of orthognathic surgery with intended manual condylar positioning on condyle by examining a change in its position.

Method: About 18 patients with mandibular prognathism who underwent orthognathic surgery with intentional manual condyle positioning were included. Condyle displacement was analyzed through 3D cone-beam computed tomography before and after operation. The patients were categorized into 2 experimental groups: group A (1-jaw) and group B (2-jaw). The experimental groups were examined before surgery (T0), 3 days (T1), and 6 months (T2) after surgery. Condylar displacement direction was investigated in terms of bodily shift and rotational movement.

Results: Downward bodily shift of condyle after surgery was significantly apparent from all of the patients. Condylar bodily shift in other directions was statistically insignificant. Gross bodily shift of condyle right after surgery was anterolateral-inferior direction. In perspective of rotational movement, condyle rotated in infero-medial direction right after operation, but no significant change was presented afterwards. In addition, no significant difference in the amounts of condylar shift and pattern existed between groups A and B.

Conclusion: Intended manual condylar positioning may minimize postoperative displacement of condyle while accomplishing skeletal stability.