Assessing the Effects of 2 Different Bone Fixation Modalities on Late Recurrence in Surgical Treatment of Patients With Angle Class 2 Malocclusion

Malocclusion disorders affecting the alignment between the upper (maxilla) and lower (mandible) jaws can lead to both aesthetic and functional problems. In Angle Class 2 malocclusion, the mandible is positioned relatively backward. Treatment typically involves orthodontic preparation followed by orthognathic surgery to advance the mandible. However, a common issue following such procedures is postoperative recurrence, where the mandible tends to revert toward its original position. One significant factor influencing recurrence is the method of bone fixation during surgery. This study aimed to compare 2 fixation techniques-3 bicortical screws (classic method) versus a combination of 1 bicortical screw and 4 monocortical screws on a plate (mixed method) in terms of long-term postoperative stability. Patients who underwent mandibular advancement through bilateral sagittal split ramus osteotomy between January 2019 and June 2023 were divided into 2 groups based on the fixation method used. Group 1 received the mixed method, while group 2 underwent the classic method. SNB angles were measured preoperatively, on the first postoperative day, and at 1-year postsurgery using CT imaging. Thirty patients (15 males, 15 females; mean age: 24.7) were followed for an average of 19 months. Results showed that group 1 had more stable SNB angles over time, with statistically significant improvements from baseline and less recurrence at 1 year. In contrast, group 2 showed greater recurrence. The mixed fixation method demonstrated superior long-term stability compared with the classic method, suggesting it may be more effective in reducing recurrence after mandibular advancement in Angle Class 2 malocclusion cases.