Skeletal stability following miniplate fixation after bilateral sagittal split osteotomy for mandibular advancement

Skeletal stability after monocortical miniplate fixation of bilateral sagittal split osteotomies to advance the mandible was evaluated in 20 patients. Three angles and four linear measurements were analyzed on lateral cephalometric radiographs before surgery, immediately after surgery, and at least 6 months after surgery. The mean horizontal advancement at pogonion was 5.0 mm; 6 months after surgery the advancement increased 0.3 mm because of occlusal settling. The mean lengthening of the distance gonion to menton was 5.8 mm and a relapse of 0.3 mm (5.2%) was found. The mean increase of anterior facial height measured at long-term follow-up was 3.6 mm. This study shows that fixation of the advanced mandible with intraorally applied monocortical miniplates after the bilateral sagittal split osteotomy is a stable procedure.