上颌复合体横向牵张的应力分布和位移的研究

Stress distribution and displacement of transpalatal distraction osteogenesis on a three-dimensional finite element model of the craniofacial complex

目的:模拟横向牵张成骨术,分析上颌骨应力分布与位移趋势。方法:在力学相似性较高的上颌骨复合体三维有限元模型上,模拟上颌第一前磨牙处牵张成骨术,计算各标志点的应力及位移。结果:第一前磨牙处加载时第一前磨牙点、尖牙点、上牙槽座点处产生较大张应力。X轴方向的最大位移在第一前磨牙基骨;Y轴方向的位移:鼻腔整体轻微后移,颧骨整体前移;Z轴方向的位移:腭平面在下降的同时伴前上旋转趋势,鼻腔整体向下移动,颧骨向上移动。结论:第一前磨牙处加载时,在牙弓前中段产生明显的骨牵张作用,牙弓中段增宽明显;鼻腔向后下移动,腭平面下降并伴前上旋转。

Objective： To simulate the state of transpalatal distraction osteogenesis on a three-dimensional finite element model of the craniofacial complex with better biomechanical similarity, and to evaluate the stress distribution and displacement. Methods： Simulated the state of maxillary transpalatal distraction osteogenesis at the first premolar region, the stress and the displacement of loading were measured at different points. Results ： When loading on the first premolar region, higher tensile stress was produced in alveolus of the first premolar and canine, and the region of ANS. Displacements of X axis ： the maximum lateral displacements were in the distraction area. Displacements of Y axis： displacement in the anteroposterior plane has been showed that the nasal cavity moved backward and the zygomatic bone moved forward. Displacements of Z axis ： on the vertical direction the palate has moved downward accompany with rotated with forward and upward. The nasal cavity has moved downward and the zygomatic bone has moved upward. Conclusion： Obvious osteogenesis can be seen in anterior and middle part of maxilla under loading. The greatest expansion is in the middle maxilla region. The nasal moves backward and downward. The palatal moves downward and rotates forward and upward.