隐形矫治器中尖牙移动设计的三维有限元分析

Three-dimensional Finite Element Analysis of Different Intrusion Mechanics Designs for Canines in Clear Aligners

目的:研究隐形矫治器前牙内收过程中尖牙的最佳力学设计。方法:本研究选取1名成年患者的CBCT影像学数据构建出上颌牙列以及隐形矫治器的有限元仿真模型,并根据内收角度的差异从0°~90°分别设计出19组载荷,依照隐形矫治器的最大移动步幅将相应的力学分配设计加载到模型上,比较分析其力学结果的差异性。结果:尖牙牙体各部分在不同力学设计下冠根呈现不同的移动现象,并随着矢状向分力减小与垂直向分力的增加呈现不同平面上移动量的衰减或递增。结论:隐形矫治器前牙内收角度区间设计在40°~50°对于尖牙来说是最佳的力学分配设计,但在此基础上还需要添加额外设计来控制轴倾和转矩的表达。

Objective:To investigate the optimal mechanical design for canines during anterior teeth intrusion with Clear Aligners.Methods:CBCT imaging data from an adult patient was selected and constructed physical models of the maxillary dental arch and invisible aligners through in vitro simulation.Nineteen sets of loads were designed based on different degrees of intrusion angles from 0 to 90 degrees.These mechanical distributions were loaded onto the models according to the maximum movement stride of the invisible aligners,and the differences in mechanical results were compared and analyzed.Results:The various parts of the canines showed different movement phenomena under different mechanical designs for the crown and root,and showed attenuation and incremental movement in different planes as the sagittal component force decreased and the vertical component force increased.Conclusion:The optimal mechanical distribution design for canines is in the range of 40 to 50 degrees for anterior teeth intrusion angle of clear aligners.However,additional design elements are required to control tooth axis and torque expression.