Effect of fixation method on intergonial width stability after mandibular setback via bilateral sagittal split osteotomy.

Q4: Horizontal changes occur following bilateral sagittal split osteotomy (BSSO) in skeletal class III patients. The aim of this study was to assess the ostoperative changes in intergonial (IG) width and compare them between the positional screw and miniplate fixation methods in BSSO. This study evaluated patients who had mandibular prognathism and underwent BSSO for mandibular setback. Internal fixation was performed bilaterally, either with positional screws in the lateral ramus or with a miniplate. Postero-anterior cephalograms were obtained preoperatively (T1), at 1 month postoperative (T2), and at 6 months postoperative (T3). The IG widths and the alterations in IG width postoperative (T2-T1, T3-T2) were measured. No correlations were observed between the amount of setback and changes at T2 -T1 or T3-T2. The IG width values decreased after mandibular setback and internal fixation with both methods. Statistical analyses showed a significant difference between T3 and T1 in the miniplate group (P=0.045). No significant difference in the postoperative change in IG width (T2-T1 and T3-T2) was found between the two fixation groups. The magnitude of this change was smaller for positional screws when compared to miniplates for fixation. The amount of mandibular setback showed no correlation with postoperative changes in IG width..