Ueki Koichiro, Marukawa Kohei, Moroi Akinori, Sotobori Megumi, Ishihara Yuri, Iguchi Ran, Kosaka Akihiko, Nakano Yoshio, Higuchi Masatoshi, Nakazawa Ryuichi, Ikawa Hiroumi
Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
Department of Oral and Maxillofacial Surgery, Division of Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3893, Japan.
J Craniomaxillofac Surg. 2014 Jul;42(5):e210-6. doi: 10.1016/j.jcms.2013.08.009. Epub 2013 Sep 14.
The purpose of this study was to evaluate bony change in an overlapped cortical bone area at the anterior site of the proximal segment after modified plate fixation with a bent plate in sagittal split ramus osteotomy (SSRO).
The subjects were 66 patients (132 sides) who underwent bilateral SSRO setback surgery. After the surgery in SSRO, an overlapped area of cortical bone at the anterior site of the proximal segment was not removed to keep the contact area between the proximal and distal segments intact, and was fixed with a bent plate and 4 screws in each side of the mandible. At the posterior site, a 3-7 mm gap was maintained between the proximal and distal segments to prevent inward-rotation of the condylar long axis. Ramus width, lateral cortex width and lateral cortex step angle were assessed in a coronal image immediately after the surgery, and 1-year postoperative by computed tomography (CT).
Ramus width after 1-year was significantly larger than that before surgery and smaller than that immediately after surgery in both sides (P < 0.0001). Lateral cortex width after 1-year was significantly larger than the preoperative value and smaller than that immediately after surgery in both sides (P < 0.0001). Lateral cortex angle after 1-year was significantly larger than the preoperative value in both sides (P < 0.0001).
The above findings suggested that the overlapped cortical bone decreased thickness and the cortical bone step disappeared following favourable bone remodelling after 1-year, even though the cortical bone was not removed at the anterior site of the proximal segment.
本研究的目的是评估矢状劈开下颌支截骨术（SSRO）中使用弯曲接骨板进行改良接骨板固定后，近端节段前部重叠皮质骨区域的骨质变化。
研究对象为66例（132侧）接受双侧SSRO后退手术的患者。在SSRO手术后，近端节段前部的皮质骨重叠区域未被切除，以保持近端和远端节段之间的接触区域完整，并在下颌骨的每一侧用弯曲接骨板和4枚螺钉进行固定。在后部位置，近端和远端节段之间保持3 - 7毫米的间隙，以防止髁突长轴向内旋转。在手术后即刻以及术后1年通过计算机断层扫描（CT）在冠状位图像上评估下颌支宽度、外侧皮质骨宽度和外侧皮质骨台阶角。
两侧术后1年的下颌支宽度均显著大于术前且小于术后即刻（P < 0.0001）。两侧术后1年的外侧皮质骨宽度均显著大于术前值且小于术后即刻（P < 0.0001）。两侧术后1年的外侧皮质骨角度均显著大于术前值（P < 0.0001）。
上述结果表明，尽管近端节段前部的皮质骨未被切除，但经过1年良好的骨质重塑后，重叠皮质骨厚度减小且皮质骨台阶消失。
