Stability after Surgical Correction of Mandibular Prognathism Using Bilateral Sagittal Split Ramus Osteotomy with Rigid Fixation

ABSTRACT

Sagittal split ramus osteotomy(SSRO) has become one of the most popular procedure for correction of mandibular prognathism. Rigid fixation is favored for its stability and patient comfort. But there were few data presented about skeletal stability and factors contributing to relapse for sagittal split ramus osteotomy with rigid fixation. From August 1997 to August 2002, eleven patients, who underwent sagittal split osteotomy with rigid fixation, were studied. Patients with genioplasty or any other orthognatic surgical procedures were excluded from sample. Lateral cephalograms were analyzed before surgery, 1 month after surgery, and 12 months after surgery. The mean amount of surgical setback was 6.29 mm at pogonion and the mean amount of skeletal relapse was 1.29 mm at pogonion. The mean postoperative horizontal change of soft tissue pogonion was 5.66 mm posteriorly, vertical change of menton was 1.83 mm superiorly, and angular change of ramus inclination was 5.88 degree increased. The mean amount of postoperative movement was 1.9 mm anteriorly at soft tissue pogonion, 2.13 mm superiorly at menton, 0.8 degree was decreases at ramus inclination. The amount of skeletal relapse is related to the amount of setback. The results of this study present that the bilateral sagittal split osteotomy with rigid fixation has many advantages and stable procedure for the correction of mandibular prognathism.