球面托槽和传统托槽作用下口腔黏膜的生物力学研究

Biomechanical Study of Oral Mucosa under the Effect of Spherical and Conventional Brackets

目的通过三维有限元分析在球面托槽以及传统托槽的作用下口腔黏膜的力学反应。方法建立上唇组织-中切牙-托槽的三维有限元模型。根据中切牙不同排列情况设计4个模拟案例,分析滑动的上唇组织分别在球面托槽以及传统托槽作用下的应力、应变情况。结果牙齿平齐时,球面托槽对口腔黏膜的最大应力较传统托槽大;切牙发生近中扭转15°、30°以及唇侧倾斜15°时,传统托槽情况下口腔黏膜最大应力均大于球面托槽最大应力。结论具有圆滑外形的球面托槽比方形传统托槽更契合牙列不齐正畸患者口腔软组织的功能运动,建议改善方形托槽的外形设计以降低口腔黏膜组织的力学反应。

Objective To explore the biomechanical responses of oral mucosa under the effect of spherical bracket and conventional bracket by three-dimensional(3D)finite element analysis.Methods The 3D finite element model of lip-incisor-bracket was established.Four simulated cases were designed according to different arrangements of central incisors,and the stress and strain of the moving upper lip under the effect of spherical bracket and conventional bracket were analyzed numerically.Results The maximum stress of spherical bracket on oral mucosa was higher than that of conventional bracket when the tooth was aligned.The maximum stress of conventional bracket on oral mucosa was higher than that of spherical bracket,when the incisor was mesially rotated by 15°and 30°,as well as labially misaligned by 15°,respectively.Conclusions Compared with square conventional bracket,spherical bracket with smooth shape is more suitable for the functional movement of oral soft tissues in orthodontic patients with misaligned teeth.It is suggested that shape design of conventional brackets should be improved to reduce mechanical response of oral mucosal tissues.