Reza Tabrizi1, Fereydoun Pourdanesh1, Hassan Mirmohammad Sadeghi2, Sholeh Shahidi3, Behnaz Poorian4. 1. Associate Professor, Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2. Assistant Professor, Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 3. Professor, Department of Oral and Maxillofacial Radiology, Biomaterial Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. 4. Senior Resident, Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: Behnazpooriang@gmail.com.
Abstract
PURPOSE: Fixation methods are important for condylar position and stability in sagittal split osteotomy (SSO) procedures. The aim of the present study was to compare the changes in the condylar position and stability after SSO for mandibular setback in plate fixation with monocortical screws and bicortical screws. PATIENTS AND METHODS: In the present retrospective cohort study, patients who had undergone mandibular setback were studied in 2 groups. In group 1, fixation was performed using a miniplate with 4 monocortical screws. In group 2, fixation was performed using 3 bicortical screws. Cone beam computed tomography scans were taken before and immediately after the SSOs and 1 year later. The condylar position was evaluated linearly (mediolateral movement in the coronal view) and angularly (condylar axis with Frankfort plane in the coronal view). The stability of the mandible was determined at the B point horizontally and vertically. RESULTS: A total of 50 patients were studied in 2 equal groups; however, 2 patients were lost to follow-up in group 2. A significant difference in the mediolateral changes of the condyle before and after osteotomy was detected between the 2 groups (P = .003). No difference was found between the 2 groups in the angular changes of the condyle before and after SSO in the coronal view (P = .45). Analysis of the data did not reveal any differences for vertical relapse at the B point (P = .47) or horizontal relapse between the 2 groups (P = .21). CONCLUSIONS: According to our results, bicortical screw fixation might be associated with more condylar displacement. However, we could not find significant differences in surgical stability between miniplate fixation with monocortical screws and bicortical screw fixation after 1 year of follow-up.
PURPOSE: Fixation methods are important for condylar position and stability in sagittal split osteotomy (SSO) procedures. The aim of the present study was to compare the changes in the condylar position and stability after SSO for mandibular setback in plate fixation with monocortical screws and bicortical screws. PATIENTS AND METHODS: In the present retrospective cohort study, patients who had undergone mandibular setback were studied in 2 groups. In group 1, fixation was performed using a miniplate with 4 monocortical screws. In group 2, fixation was performed using 3 bicortical screws. Cone beam computed tomography scans were taken before and immediately after the SSOs and 1 year later. The condylar position was evaluated linearly (mediolateral movement in the coronal view) and angularly (condylar axis with Frankfort plane in the coronal view). The stability of the mandible was determined at the B point horizontally and vertically. RESULTS: A total of 50 patients were studied in 2 equal groups; however, 2 patients were lost to follow-up in group 2. A significant difference in the mediolateral changes of the condyle before and after osteotomy was detected between the 2 groups (P = .003). No difference was found between the 2 groups in the angular changes of the condyle before and after SSO in the coronal view (P = .45). Analysis of the data did not reveal any differences for vertical relapse at the B point (P = .47) or horizontal relapse between the 2 groups (P = .21). CONCLUSIONS: According to our results, bicortical screw fixation might be associated with more condylar displacement. However, we could not find significant differences in surgical stability between miniplate fixation with monocortical screws and bicortical screw fixation after 1 year of follow-up.