抄録
Orthognathic surgery is performed to establish functional occlusion and to make esthetic improvements. The most common surgical procedures are Le FortⅠosteotomy and sagittal split ramus osteotomy（SSRO）. Generally, their postoperative course is uneventful. In many facilities in Japan, the plates are removed approximately one to two years after osteotomy. We report a case of refixed non-unioned maxilla caused by a fractured plate, 15 months after a Le FortⅠosteotomy, which has not been reported previously.
A 43-year-old man visited our hospital with a chief complaint of concave profile and malocclusion. Subsequently he underwent Le FortⅠosteotomy and SSRO. Facial findings were symmetric from the frontal view and a concave profile from the lateral view. Intraoral findings revealed an overjet of−8 mm and an overbite of＋5 mm, showing ClassⅢmolarization. Cephalometric analysis revealed ANB:−13.4°, U1 to SN: 108.1°, L1 to mandible: 69.0°, FMA: 19.0° and gonial angle: 121.3°. He was diagnosed as SkeletalⅢand Dental ClassⅢwith a low mandible and short face. Intraoperatively, the maxillary segments were rigidly fixed by 5 titanium plates in the piriformis margin and zygomatic buttress after the maxilla advanced 5 mm. They were not filled with an autogenous bone graft after the Le FortⅠosteotomy because we confirmed immobilization of the maxilla. The patient was satisfied with the results of the operation. The postoperative course has been uneventful since then. However, mobility of the maxilla was found 15 months after the Le FortⅠosteotomy. We diagnosed this as a non-unioned maxilla, and performed surgery to refix the non-unioned maxilla. One of the titanium plates in the piriformis margin on the right side had completely fractured, and the other titanium plates had become loose. Therefore, the fractured plate and another plate were replaced by new ones. In addition, a bone graft harvested from the mandibular ramus was placed with screws in the gap between the maxillary segments. At present, the postoperative course has been uneventful without complications to date. We need to take into account the possibility of plate fractures for patients with short faces, due to the overload coming from the occlusal force and the necessity of a larger movement
