Changes of Transverse Mandibular Width in Set-Back Mandibular Surgery: Sagittal Split versus Intraoral Verticosagittal Osteotomy

Aim: This study was performed to evaluate the movement of the proximal segment following different methods of ramus osteotomy that is one of the side effects of orthognathic surgery. Theoretically, with intraoral verticosagittal ramus osteotomy, it can minimize the movement of the proximal segment. The changes in the intergonal distance of mandible and the angle of the ramus flaring in two methods of osteotomy have been compared in this study. Materials and Methods: In this randomized clinical trial, included 60 patients (32 males) with mandibular prognathism and without any asymmetry were selected and divided into two groups (n = 30). One group underwent bilateral sagittal split ramus osteotomy technique to achieve mandibular setback and the other by the intraoral verticosagittal ramus osteotomy technique. Intergonial width and inner-ramal angle in the transverse plane were measured on radiographs preoperatively and 1 and 12 weeks postoperatively. Data were analyzed using covariance test with the significance level set at P < 0.05. Results: Changes of intergonial width and inter-ramal angle was significant in both the 1 and 12-week radiographies taken post-operative in both groups. But no statistically significant difference was observed in the intergonial width and ramus flaring at the mentioned time points between the two groups (P > 0.1). Conclusion: Considering our findings, there was no significant difference between two ramus osteotomy techniques regarding changes in mandibular width and inter-ramal flaring angle.