Tabrizi Reza, Pourdanesh Fereydoun, Sadeghi Hassan Mirmohammad, Shahidi Sholeh, Poorian Behnaz
Associate Professor, Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Assistant Professor, Department of Oral and Maxillofacial Surgery, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
J Oral Maxillofac Surg. 2017 Dec;75(12):2668.e1-2668.e6. doi: 10.1016/j.joms.2017.08.031. Epub 2017 Aug 31.
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.
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.
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).
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.
在矢状劈开截骨术（SSO）中，固定方法对于髁突位置和稳定性至关重要。本研究的目的是比较单皮质螺钉和双皮质螺钉钢板固定下颌后缩SSO术后髁突位置和稳定性的变化。
在本回顾性队列研究中，对两组接受下颌后缩手术的患者进行了研究。第1组使用带有4枚单皮质螺钉的微型钢板进行固定。第2组使用3枚双皮质螺钉进行固定。在SSO术前、术后即刻及1年后进行锥形束计算机断层扫描。通过线性（冠状位视图中外侧移位）和角度（冠状位视图中髁突轴线与法兰克福平面）评估髁突位置。在下颌骨B点水平和垂直方向测定下颌骨的稳定性。
两组共研究了50例患者；然而，第2组有2例患者失访。两组之间截骨术前、后髁突外侧移位变化存在显著差异（P = 0.003）。在冠状位视图中，两组之间SSO术前、后髁突角度变化无差异（P = 0.45）。数据分析未显示两组在B点垂直复发（P = 0.47）或水平复发方面存在任何差异（P = 0.21）。
根据我们的结果，双皮质螺钉固定可能与更多的髁突移位有关。然而，随访1年后，我们未发现单皮质螺钉微型钢板固定和双皮质螺钉固定在手术稳定性方面存在显著差异。
