Five-year skeletal and dental stability following bilateral sagittal split osteotomy for mandibular advancement in Class 2 malocclusion

Abstract

Background Bilateral sagittal split osteotomy (BSSO) is widely used for mandibular advancement in patients with skeletal Class 2 malocclusion; however, long-term postoperative stability remains an important clinical concern. Purpose To evaluate long-term skeletal, dentoalveolar, and soft tissue stability following mandibular advancement with BSSO and rigid fixation. Methods A retrospective cohort study was conducted in 32 patients undergoing mandibular advancement with BSSO and rigid fixation. Cephalometric measurements were obtained at four time points: preoperative, immediate postoperative, 12 months, and long-term follow-up (>3 years). Changes were analyzed using the Wilcoxon signed-rank test. Results The mean mandibular advancement was 5.42 ± 1.71 mm. Immediately after surgery, significant skeletal correction was achieved, with increased SNB and decreased ANB (both p < 0.001), accompanied by significant improvements in occlusal and soft tissue profile measurements. Most skeletal and occlusal parameters remained stable during the first postoperative year and throughout long-term follow-up, with no statistically significant changes observed between one year and the final evaluation. Soft tissue remodeling continued during follow-up, whereas overall skeletal and dental stability was maintained. Conclusion Bilateral sagittal split osteotomy with rigid fixation effectively corrected skeletal Class 2 malocclusion and demonstrated favorable long-term skeletal, dental, and soft tissue stability.