Evaluation of mandibular anatomy related to sagittal split ramus osteotomy using 3-dimensional computed tomography scan images.

Sagittal split ramus osteotomy (SSRO) of the mandible is one of the most common surgical techniques to correct mandibular deformities. Measurement of nerve position using conventional methods has been reported in the literature, but surgeons have found that further investigation of the anatomical relationship is needed. The aim of this study was to attempt to increase the accuracy of treatment by using 3-dimensional computed tomography scan measurements. From the normal population, 20 females and 20 males were enrolled during planning of denture implants in Taiwan. The mean age was 28+/-6, ranging from 20 to 39 years old. Using 3D tomography data, nerve position at osteotomy sites was measured and the geometric relationship examined between the antilingula and mandibular foramen. The results gave the mean distance from buccal plate to mandibular canal at the second molar, from mandibular canal to inferior border of the mandibular body, from the mandibular foramen to the highest tip of the lingula, and from the mandibular foramen to the anterior margin of the oblique ridge. When applied to SSRO operations, the anatomic data provided by this study may help surgeons gain more understanding of nerve position during surgery.