Comparable aesthetic outcomes of a hybrid modified intraoral vertico-sagittal ramus osteotomy technique and conventional bilateral sagittal split ramus osteotomy for asymmetric mandibular prognathism in a youthful population.

Conventional bilateral sagittal split ramus osteotomy (BSSRO) for asymmetric mandibular prognathism carries risks to the temporomandibular joints and inferior alveolar nerve. A hybrid technique, combining a modified L-shaped intraoral vertico-sagittal ramus osteotomy (mIVSRO) with a contralateral SSRO, may mitigate these risks, but its aesthetic outcomes are unproven. The aim of this study was to compare the aesthetic efficacy of the hybrid versus conventional BSSRO techniques, adjusting for baseline asymmetry. This retrospective cohort study compared 30 patients with asymmetric mandibular prognathism treated with either the hybrid technique (n = 15) or conventional BSSRO (n = 15). Soft and hard tissue changes were assessed using frontal photographs and cephalograms. Postoperative aesthetic outcomes were compared using analysis of covariance (ANCOVA) to adjust for baseline differences. After ANCOVA adjustment, no significant differences were found in the correction of soft or hard tissue chin deviation between the groups. There was greater residual gonial angle asymmetry (P = 0.054) and soft tissue face plane cant (P = 0.065) in the hybrid group when compared to the BSSRO group, although neither comparison reached statistical significance. Notably, all postoperative neurosensory disturbances in the hybrid cohort occurred on the SSRO-treated side. The hybrid osteotomy technique provides aesthetic correction of chin deviation with no significant difference detected when compared to conventional BSSRO. Given its functional advantages, particularly the confinement of neurosensory risk to the SSRO side as demonstrated in this study, the hybrid approach is a valuable alternative for managing asymmetric mandibular prognathism, especially in high-risk patients.