The effects of fixation methods on relapse after sagittal split ramus osteotomy

Orthognathic surgery is a surgical technique performed to correct skeletal deformities in the jaw and facial region. It is planned in coordination with orthodontic treatment to correct various functional and structural disorders such as positional disorders of the upper and lower jaw, anomalies in chewing and biting functions, airway problems and aesthetic concerns. In orthognathic surgery operations, it is of great importance not only to achieve a successful result but also to maintain this result. Unexpected changes in skeletal, dental and soft tissue after surgery are called relapse. Skeletal relapse is affected by many factors and is observed more frequently. This study included 40 patients who applied to Suleyman Demirel University Faculty of Dentistry, Department of Oral and Maxillofacial Surgery between 2015 and 2024 and who were indicated for bimaxillary surgery based on clinical and radiologic evaluation. All patients underwent sagittal split ramus osteotomy and were divided into two groups based on the fixation method. 20 patients in the first group were fixed with bicortical screws, while 20 patients in the second group were fixed with monocortical screws and plates. The evaluation of the patients was based on lateral cephalometric radiographs taken preoperatively (T0), 1 week postoperatively (T1) and 6 months postoperatively (T2). The data were analyzed using WebCeph cephalometric analysis software and compared in terms of postoperative change (T1-T0) and postoperative recurrence (T1-T2). There were no significant differences between the groups in skeletal, dental and soft tissue measurements in patients with bicortical screw and monocortical screw plates. Therefore, considering its advantages such as ease of application, lower risk of nerve damage and no excessive force on the condyle, monocortical screw-plate system may be a safer and more effective fixation method. Keywords: Orthognathic surgery, Fixation, Relapse