Is symphyseal split osteotomy a stable method in the treatment of transverse mandibular width discrepancies?

Mandibular symphyseal split osteotomy is an orthognathic procedure used to correct transverse mandibular deficiencies. Limited data exist regarding the stability of transverse mandibular widening achieved with this technique. We set out to evaluate the stability of transverse mandibular widening following symphyseal split osteotomy and report outcomes when combined with genioplasty.

This retrospective cohort study included patients who underwent symphyseal split osteotomy for mandibular transverse discrepancies between September 2021 and January 2023. The predictor variable was planned transverse widening determined by virtual surgical planning. The primary outcome was transverse mandibular stability, defined as the difference between planned dimensions and postoperative cone-beam CT measurements at the intercanine and intermolar levels. Changes in mandibular first molar mesiolingual cusp distance were also evaluated.

Five of 7 patients met inclusion criteria. Mean intercanine and intermolar differences between planned and postoperative measurements were -0.17 ± 1.06 mm (P = .74) and 0.56 ± 1.92 mm (P = .55), respectively. Mean mesiolingual cusp distance increased from 35.32 ± 2.66 mm to 37.70 ± 2.28 mm, with a mean increase of 2.38 ± 2.03 mm (P = 0.058).

Mandibular symphyseal split osteotomy provides stable transverse widening with low morbidity. Virtual surgical planning, rigid fixation, and postoperative splinting produced predictable outcomes.