The purpose of this study was to explore the incidence of
injuries to the teeth at the vertical
osteotomy line after segmental Le Fort I
osteotomy by examination of postoperative cone beam computed tomography (CBCT) images. Data for this retrospective case study were collected using CBCT images of 132 patients with an indication for Le Fort I
osteotomy with three-piece segmentation of the maxilla. Twenty-two patients (17%, 95% confidence interval 10-23%) had dental
injuries. No patient had more than one dental injury. Thirty-three patients (25%, 95% confidence interval 18-32%) had bone dehiscence of the teeth (defined as the
osteotomy line passing through the periodontal ligament). Six patients had bone dehiscence involving two teeth and one patient had bone dehiscence involving three teeth. In the group in which dental
injuries occurred, the preoperative interdental distance at the vertical
osteotomy line was significantly shorter than the interdental distance in the group without dental
injuries. In conclusion, this study demonstrated that a preoperative interdental distance of more than 2.5mm significantly reduced the possibility of
tooth injuries adjacent to the vertical
osteotomy line during Le Fort I
osteotomy with three-piece segmentation of the maxilla.