犬下颌单侧牵张成骨位移趋势有限元分析

Canine mandibular displacement analysis by means of finite element method on partial-cortical-cutting distraction osteogenesis

目的:利用犬不完全截骨牵张成骨的有限元模型观察牵张过程中下颌骨特定点位移趋势。方法:有限元模型模拟不完全截骨(截骨处剩1mm舌侧皮质骨),观察下颌骨一些特定标志点在牵张过程中空间三维的位移趋势。结果:在牵张过程中牵张侧下颌骨标志点位移趋势为在内外(左右或X轴)方向上第五臼齿、喙突、髁状突前斜面前缘中点的位移趋势是向外的,而下颌角、髁状突后斜面后缘中点的位移趋势是向内的;在前后(Y轴)方向上第五臼齿、喙突的位移趋势是向后的,而下颌角的位移趋势是向前的;在上下(Z轴)方向上第五臼齿的位移趋势是向上的。结论:牵张侧下颌骨在矢状平面上有使下颌骨体前端拉高后端压低的倾向,在冠状平面上有使下颌骨体上缘外翻下缘内收的倾向。

Abstract Objective：To observe the displacement of every mandibular part duing distraction osteogenesis by means of the finite element model of canine partial-cortical-cutting distraction osteogenesis.Methods：The method of finite element analysis was used to simulate partial-cortical-cutting the distraction osteogenesis.The displacement trend of some points marked in the mandible were observed in ＂cut＂ situation when lmm wide of slice was retained during distraction osteogenesis with the force of 12 newton.Results：When the slide seg- ment was retained lmm width,the fifth cheek tooth and anterior edge midpoint of condyle process anterior slope and coracoid process showed negative displacement and the angle of mandible and the posterior edge midpoint of condyle process posterior slope showed positive displacement on X axes.The fifth cheek tooth and the coracoid process showed positive displacement and the angle of mandible showed negative displacement on Y axes.The fifth cheek tooth showed positive displacement on Z axes.Conclusion：At the side of distraction the mandible body has the trend of anterior extremity boosted and posterior extremity depressed in the sagittal plane and has the trend of superior border everted and inferior border adducted in the coronal plane.