Evaluation of stability after orthognathic surgery with minimal orthodontic preparation: comparison according to 3 types of fixation.

This study was performed to evaluate the patterns and amount of postsurgical relapse after mandibular setback surgery with minimal orthodontic preparation. We also compared the stability of plate according to types. From January 2009 to February 2012, 26 patients (13 males, 13 females) at Seoul National University Bundang Hospital were identified. All patients underwent presurgical orthodontic treatment in less than 6 months and had mandibular setback surgery. Lateral cephalograms were taken presurgically (T0), immediately after surgery (T1), and 6 months after surgery (T2). To evaluate surgical change and surgical relapse, linear and angular measurements were performed, and results were analyzed. Comparison of the vertical and horizontal relapses between groups (group 1: sliding plate, group 2: conventional metal plate, group 3: resorbable plate) was also performed. The overall mandibular relapse was 2.80 (SD, 3.86) mm (pogonion) and 3.85 (SD, 4.44) mm (menton) anteriorly, and 1.2 (SD, 3.39) (pogonion) and 1.47 (SD, 3.48) mm (menton) superiorly. There was no significant difference among the 3 groups, however (P > 0.05). When mandibular setback surgery was performed, surgical relapse would occur anteriorly and superiorly. Significant difference can hardly be found among the 3 groups in terms of the amount of vertical and horizontal relapses.