解剖[牙合]型与舌侧集中[牙合]型对下颌Ⅳ类无牙颌的牙槽骨和黏膜影响的三维有限元分析

Three-dimensional finite element analysis of the effects of anatomical occlusion and lingualized occlusion on alveolar bone and mucosa of ClassⅣedentulous jaw

目的研究解剖[牙合]型、舌侧集中[牙合]型在正中及侧方咬合时对下颌Ⅳ类无牙颌的黏膜与下方牙槽骨的生物力学特性变化。方法创建下颌Ⅳ类无牙颌下颌骨有限元模型,在下颌骨上使用解剖[牙合]型、舌侧集中[牙合]型,人工牙分别进行正中咬合、侧方咬合仿真模拟,分析黏膜及牙槽骨的生物力学变化。结果正中咬合时,黏膜压应力舌侧集中[牙合]型比解剖[牙合]型降低0.6%~31.2%;牙槽骨表面压应力,左侧磨牙区和前牙区牙舌侧集中[牙合]型比解剖[牙合]型下降19.0%~35.1%,而右侧磨牙区舌侧集中[牙合]型比解剖[牙合]型上调53.3%;左侧侧方咬合状态下黏膜及牙槽骨应力分布:舌侧集中[牙合]型较解剖[牙合]型下降41.1%~70.2%;右侧侧方咬合状态下黏膜及牙槽骨应力分布:舌侧集中[牙合]型较解剖[牙合]型下降24.4%~63.8%。结论下颌Ⅳ类牙槽骨无牙颌修复在正中咬合时,舌侧集中[牙合]型比解剖[牙合]型降低左侧及前牙区低平牙槽骨上的黏膜与牙槽骨压应力;在侧方咬合时,降低前牙区及两侧磨牙区黏膜与牙槽骨压应力,为临床下颌牙槽骨吸收严重患者选择合适人工[牙合]型提供理论参考。

Objective To compare the changes of biomechanical properties of mucosa and inferior alveolar bone of ClassⅣedentulous jaw of complete denture corresponding to anatomical occlusion and lingualized occlusion under two different load conditions of median occlusion and lateral occlusion.Methods The finite element model of the ClassⅣedentulous mandible was established,anatomical occlusion and lingualized occlusion were supplemented to the mandible,to simulate the median occlusion and lateral occlusion respectively.The biomechanical changes of the mucosa and alveolar bone were analyzed.Results Under the condition of median occlusion,the mucosal compressive stress of lingualized occlusion was smaller than of anatomic occlusion,and the decrease of mucosal compressive stress was about 0.6%-31.2%.The compressive stress on the upper surface of alveolar bone in the left molar area and anterior tooth area of lingualized occlusion was smaller than that of anatomic occlusion,and the decrease of alveolar bone stress was about 35.1%-19.0%,On the contrary,the alveolar bone compressive stress in the right molar area was 53.3%higher than that of anatomic occlusion.In the left lateral occlusal state,the compressive stress of lingualized occlusal on mucosa and alveolar bone decreased by 70.2%-41.1%.In the right lateral occlusal state,the compressive stress of lingualized occlusal on mucosa and alveolar bone decreased by 63.8%-24.4%.Conclusion In the restoration of ClassⅣedentulous jaw,the lingualized occlusion reduces the mucosal and alveolar bone compressive stress in the anterior tooth area and left molar area of the low flat alveolar bone of median bite compared with the anatomic occlusion type.And it is reduced in the anterior tooth area and bilateral molar area in the lateral bite,so as to provide a theoretical reference for clinical patients with severe mandibular alveolar bone resorption.