目的 通过三维有限元分析探索在球面托槽以及传统托槽的作用下口腔粘膜的力学反应。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值较传统托槽的大；切牙发生近中扭转15°、30°以及唇侧倾斜15°时,传统托槽情况下的口腔黏膜最大应力均大于球面托槽的最大应力。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 Finite element analysis was carried out to explore the biomechanics of mucosal responses to mechanical stimulation from the spherical self-ligating bracket and conventional bracket. Methods A three-dimensional finite element model of lip-incisor-bracket was established. Four simulated cases were designed and analyzed numerically according to different arrangements of central incisors, and the stress and strain of the moving upper lip under the spherical bracket and the conventional bracket was explored individually. Results The maximum stress of spherical bracket on mucosa was higher than that of conventional bracket when tooth was aligned. The maximum stress of conventional bracket on oral mucosa was higher than that of spherical bracket concerning that the incisor had a mesial torsion of 15° and 30°, as well as labially misaligned by 15° respectively. Conclusions Compared with the square conventional brackets, the spherical brackets with smooth shape are more suitable for the functional movement of oral soft tissue in orthodontic patients with irregular dentition. It is suggested to improve the shape design of the conventional brackets to reduce the mechanical response of oral mucosal tissue.