Stability After Bilateral Sagittal Split Osteotomy With Rigid Internal Fixation in Surgery-First Approach

The purpose of this study was to evaluate the stability of bilateral sagittal split ramus osteotomy (BSSO) setback with rigid internal fixation in a surgery-first approach (SFA) for patients with skeletal Class III malocclusion.

Twenty-seven consecutive patients with skeletal Class III malocclusion treated with BSSO with the SFA were included in the study. Lateral cephalograms were taken and traced before surgery and 1 and 6 months after surgery. Cephalometric measurements were compared using repeated-measures analysis of variance. A P value less than or equal to .05 was considered significant.

The study included 9 men (age, 25.7 ± 2.9 yr) and 18 women (age, 26.6 ± 4.2 yr). Treatment time was 8.4 ± 1.5 months. Horizontally, there were no meaningful anteroposterior changes of the pogonion and B point during the postsurgical period (0.9 and 0.6 mm, respectively). Vertically, the pogonion showed superior movement after surgery (2.4 mm) without major postsurgical change (0.6 mm). The B point showed major superior movement after surgery (2.3 mm) and during the postsurgical period (1.2 mm). The inclination of the lower incisor was increased labially during the postsurgical period (2.4°), although this was not statistically important.

In the present study, there was no major horizontal relapse for any variable (<1 mm). Vertically, all variables showed no meaningful changes during the postsurgical period except the B point showed 1.2 mm of superior displacement. BSSO with rigid fixation using the SFA seems to be an effective and predictable procedure in patients with skeletal Class III malocclusion.