Stability of sagittal split osteotomies

The objective of this study was to retrospectively evaluate stability of mandibular advancement after bilateral sagittal split osteotomies were performed. Three different fixation and immobilization protocols were examined. Thirty-three patients were evaluated with preoperative, immediate postoperative, and long-term (mean, 13 months) lateral cephalometric radiographs. The patients were divided into three groups: group 1 (n = 10) had nonrigid internal fixation and 6 weeks of maxillomandibular fixation, group 2 (n = 12) had rigid internal fixation and immediate postoperative function, and group 3 (n = 11) had rigid internal fixation with maxillomandibular fixation for a mean of 14 days. Group 3 had the least amount of sagittal and vertical relapse. Differences in sagittal relapse were statistically significant between groups 1 and 3. Group 2 demonstrated greater sagittal relapse than did group 3, although the result was not statistically significant. This study suggests that the use of rigid internal fixation with a period of maxillomandibular fixation appears to be more stable than nonrigid internal fixation with maxillomandibular fixation or rigid internal fixation without maxillomandibular fixation.