扭转上颌第一前磨牙的三维有限元应力分析

Three dimensional finite element stress analysis on rotating maxillary first premolar

目的研究对上颌第一前磨牙施加不同大小及方向的矫治力时,牙体的受力及位移变化规律,为临床扭转牙齿的矫治提供相关的理论依据。方法建立上颌第一前磨牙及其周围组织的三维有限元模型,研究仿真模拟于牙冠的颊、舌面临床冠中心施加一对大小相等方向相反的力偶情况下牙体的受力状况。结果在不同的加载条件下,扭转上颌第一前磨牙的牙颈部均为应力集中区。随着牵引力的增大,牙体的位移及应力值均增大。牵引力与X轴间的角度越大,牙体的应力及位移越小。结论临床中应尽量采用轻力,施力方向与X轴应尽量平行,在使牙体有效移动的同时尽量减少或避免牙体吸收。

Objective To study the variation law of the stress and displacement of teeth while exerting correctional forces of different magnitudes and directions, to provide relevant theoretical basis for the clinical treatment of the rotated teeth. Methods To estab- lish a three-dimensional finite element model of the maxillary first premolar as well as its surrounding tissues, and to study the stress distribution in the clinical crown centers of the huccal and lingual face exerting a pair of equal size but opposite direction forces. Results Under different loading conditions,the stress concentrations were observed at the neck of the rotated maxillary first premolar tooth . With the increase of the force, the tooth displacement and the maximum stress value increased. Tooth displacement was larger when the angle between the force and the X axis was smaller. Conclusions The force should be lighter,and the force direction and the X axis should he in parallel to prevent tooth from absorbing.