Extended Maxillary Osteotomy Guide: A Design That Allows Manipulation of the Osteotomy Direction on the Posterior and Inner Walls of the Maxilla.

PURPOSE: Design an extended osteotomy guide (EOG) for Le Fort I osteotomy to improve the safety of surgery. MATERIALS AND METHODS: The digital Le Fort I osteotomy guide was designed in MIMICS 23.0. Twenty-eight patients were randomized into 2 groups. Patients in the experimental group used EOG, and patients in the control group used a traditional osteotomy guide (TOG). Virtual designs and actual postoperative outcomes were compared by cone-beam computed tomography. The safety of the operation was confirmed by the accuracy of the osteotomy direction and depth on the inner and posterior walls of the maxilla. RESULTS: All positioning deviations of both osteotomy guides were <0.3 mm (P>0.05). The osteotomy depths on the inner and posterior walls with the EOG and TOG deviated by 0.789+/-1.179 and 1.811+/-1.345 mm (P=0.004) and 0.648+/-0.999 and 1.262+/-0.942 mm (P=0.030), respectively. The angles of deviation of the osteotomy direction on the inner and posterior walls by the EOG and TOG were 2.025+/-2.434 and 5.069+/-2.391 degrees (P<0.001) and 2.772+/-2.979 and 8.653+/-4.690 degrees (P<0.001), respectively. CONCLUSIONS: The EOG was more accurate than TOG for manipulating osteotomy direction and depth on the inner and posterior maxillary walls. Thus, EOG could ensure higher surgical safety than TOG.