Influence of different sagittal split osteotomy techniques on bone contact in mandibular advancement: a double-blind randomized clinical trial

This randomized, double-blind, single-center controlled clinical trial compared sagittal split osteotomy (SSO, Dal Pont modification as refined by Epker) and anterior oblique osteotomy (AOO) in terms of lingual split patterns and bone contact area (BCA) following mandibular advancement. The study included 52 patients (104 osteotomies) with skeletal class II facial and occlusal patterns who underwent orthognathic surgery. Fracture patterns were classified according to Plooij (2009) into four types using Lingual Split Scale (LSS). The magnitude of point B advancement and BCA between proximal and distal segments were measured using Dolphin Imaging software. The SSO group demonstrated a significantly greater BCA compared to the AOO group ( P < 0.001). The magnitude of mandibular advancement ( P = 0.14) and execution time ( P = 0.081) were similar between groups. However, the distribution of lingual cortical split patterns differed significantly ( P < 0.001). In the SSO group, LSS3 fractures predominated, followed by LSS1, whereas the AOO group showed a higher prevalence of LSS1 fractures, followed by LSS2 and LSS3. Although no absolute superiority of either technique was observed, SSO resulted in greater BCA and may therefore be considered the preferred technique for large mandibular advancements.