个性化舌侧托槽长度对改中切牙扭转效能的三维有限元分析

A 3D-FEM study of effect of individualized lingual bracket with different slot lengths to the central incisor rotation performance

目的:通过构建舌侧矫治技术纠正扭转中切牙的三维有限元模型,比较具有不同槽沟长度的个性化舌侧托槽对扭转中切牙的矫正效能。方法:对符合纳入标准的牙及支持组织进行CBCT扫描,建立三维有限元模型。模型包含近舌扭转10°的右上中切牙及其2颗邻牙、牙周膜、牙槽骨、e-Brace个性化舌侧托槽及弓丝,运用有限元法分析不同槽沟设计的托槽对扭转中切牙的矫正效能。结果:建立了包含牙、牙周膜、牙槽骨、e-Brace托槽及弓丝在内的4组三维有限元模型。随舌侧托槽槽沟长度的增加,右上中切牙的整体位移变化及牙周膜总体等效应力值均增大。结论:在不损伤牙周组织的安全范围内,槽沟长度为牙冠宽度的3/4(6.3 mm)的舌侧托槽,对纠正扭转的右上中切牙效能最显著。

Objective： To compare the performances correcting the rotational upper right central incisor when use the individualized lingual brackets with different slot lengths by constructing a lingual 3 D finite element method（ FEM） with rotational upper right central incisor. Methods： After scanning the standard dentition and its periodontal tissues,a 3-D FEM,including the 10 degree medially and lingual rotational upper right central incisor and its adjacent teeth,periodontal ligament（ PDL）,alveolar bone,e-Brace brackets,and lingual wire,was constructed,and then to analysis the rotation performances with them,using finite element method. Results： Four 3-D FEM models were constructed,including dentition,PDL,alveolar bone,e-Brace brackets,and lingual wire. With the lingual bracket slot lengths increasing,the total deformation and periodontal ligament stress of upper right central incisor increase. Conclusion： Within safe levels of periodontal ligament stress,the lingual bracket with 3/4 crown wide（ 6. 3 mm） slots length got the greatest therapeutic effect for correcting the rotational upper right central incisor.