Abstract
Orthodontic surgery improves stomatognathic functions such as mastication, swallowing, and pronunciation in patients with jaw deformity, as well as improving esthetics in facial features and dentition. It also contributes to the improvement of patients’ psychosocial problems and QOL. Among jaw deformity, 87％ are diagnosed with mandibular protrusion or mandibular retrusion, and most of them require mandibular surgery. Sagittal split ramus osteotomy （SSRO） and intraoral vertical ramus osteotomy （IVRO） are typical mandibular surgeries. However, intraoperative complications such as abnormal fractures and massive bleeding have been reported during these surgeries. Preoperative imaging diagnosis and planning are important for safety. Recently, preoperative evaluation using CT （computed tomography） has become common, in addition to conventional diagnosis and analysis using X-ray images such as cephalometric prediction. Further, preoperative surgical planning using 3D models and 3D simulation of orthognathic surgery using software are becoming popular. In the present review, we describe the key points of preoperative diagnostic imaging for safety and reliability during SSRO and IVRO.
