Hanaue Kenichi, Katakura Akira, Kasahara Kiyohiro, Kamiyama Isao, Takaki Takashi, Shibahara Takahiko, Abe Shinichi, Ide Yoshinobu
Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Chiba, Japan.
Bull Tokyo Dent Coll. 2007 Nov;48(4):163-70. doi: 10.2209/tdcpublication.48.163.
We performed sagittal splitting osteotomy using fresh, unfixed cadavers. Observation was carried out macroscopically and with light microscopy and 3-dimensionally reconstructed images. The aim of this study was to clarify the relationship between the fracture line and the Haversian canal and Haversian lamellae. Macroscopic observation revealed that the fracture line run through the mandibular angle from the inferior rim of the mandibular ramus towards the posterior rim, passing almost through the center of the ridgeline. Histological observation showed that the fracture line tended to run along the curve of the lamellar structure. The incidence of the fracture line running along the lamellar structure of the Haversian lamellae was approximately 65% (21 cases), and the incidence of the fracture line also cutting across the Haversian canal without passing along the lamellar structure of the Haversian lamellae was approximately 35% (11 cases). Observation of 3-dimensional reconstruction images revealed that the section of Haversian canal near the mandibular angle essentially runs from the mandibular head to the inferior rim of the mandible, and that the fracture plane ran similarly. The direction of an impact-associated bone fracture line is influenced by the structures that constitute the lamellar bone such as Haversian canals, Haversian lamellae and interstitial lamellae, with fracture lines tending to run through those parts of the bone that have a low physical bond strength. This suggests that the ideal direction of action of the bone chisel in sagittal splitting surgery is the one in which no resistance to the path of the Haversian canal is encountered.
我们使用新鲜、未固定的尸体进行矢状劈开截骨术。通过宏观观察、光学显微镜观察以及三维重建图像进行研究。本研究的目的是阐明骨折线与哈弗斯管和哈弗斯骨板之间的关系。宏观观察显示，骨折线从下颌支下缘向后方边缘穿过下颌角，几乎经过嵴线的中心。组织学观察表明，骨折线倾向于沿着板层结构的曲线走行。沿着哈弗斯骨板的板层结构走行的骨折线发生率约为65%（21例），而骨折线也横穿哈弗斯管且不沿着哈弗斯骨板的板层结构走行的发生率约为35%（11例）。三维重建图像观察显示，下颌角附近的哈弗斯管截面基本上从下颌头延伸至下颌骨下缘，骨折平面的走行与之相似。与撞击相关的骨折线方向受构成板层骨的结构（如哈弗斯管、哈弗斯骨板和骨间板）影响，骨折线倾向于穿过骨中物理结合强度较低的部位。这表明矢状劈开手术中骨凿的理想作用方向是不遇到哈弗斯管走行阻力的方向。
