不同Ⅱ类牵引模式对无托槽隐形矫治磨牙远移作用的比较:三维有限元研究  

Comparison of the effects of two types of Class Ⅱ elastics on the molar distalization with clear aligners:a three-dimensional finite element research

作　　者：雷鹤 陶洪[1] 罗晶 张楠[1] 陈江浩 邓春妮 陈曦[1] Lei He;Tao Hong;Luo Jing;Zhang Ncm;Chen Jianghao;Deng Chunni;Chen Xi(Department of Stomatology,The First Affiliated Hospital,College of Medicine,Xi'an Jiaotong University,Shannxi 710000,China)

机构地区：[1]西安交通大学第一附属医院口腔科,710000

出　　处：《中华口腔正畸学杂志》2021年第3期152-156,共5页Chinese Journal of Orthodontics

摘　　要：目的构建隐形矫治器上颌磨牙远移中两种Ⅱ类牵引的生物力学研究模型,分析矫治体系在不同加力模式、不同牵引力大小作用下的初始位移及应力分布特点,为该技术的临床应用提供参考.方法建立隐形矫治推上颌磨牙向远中及两种Ⅱ类牵引模式(牙套加力组与牙齿加力组)的三维有限元模型,采用非线性有限元法分析2种不同加力方式及5种不同载荷(100 g、150 g、200 g、250 g、300 g)下的牙齿移动方式、牙套形变、牙周膜应力分布等,比较其增强前牙支抗效果的异同.结果不同力值不同加力方法下所有组Ⅱ类牵引均可以使前牙内收,抵抗磨牙远中移动过程造成的前牙支抗丧失,但其牙齿应力分布、牙套形变效果不同:牙齿加力组集中在直接受力的尖牙上,分布不均匀;牙套加力组分布更均匀,随距尖牙距离由近到远逐渐减小,但总体大小较牙齿加力组大.牙周膜等效应力除300 g牙套加力组[(2.87×10^(-2))MPa]过大外,其余各组均在牙周膜可承受范围内.结论100 g的Ⅱ类牵引即可抵抗磨牙远移反作用力造成的前牙支抗丧失,300 g牙套加力作用下的牙周膜受力过大,尽量避免使用.Objective To establish a biomechanical model of maxillary molar distalization with clear aligners and two modes of Class Ⅱ elastics,and to analyze the initial displacement and stress distribution of the orthodontic system under different force environments to provide reference for the clinical application.Methods A 3D finite element(FE)model of maxillary molars distalization with two modes of Class Ⅱ elastics(on aligners and on teeth)was conducted.Nonlinear analysis was used to evaluate tooth movement pattern,aligner distortion and stress distribution among periodontal ligament under five force environments(100 g,150 g,200 g,250 g,300 g)with two kinds of Class Ⅱ elastics.The effects of elastics on anchorage enhancement were compared between the two modes.Results All the anterior teeth retracted in each group of Class H elastics,while preserved the anterior anchorage.However,the stress distribution and aligner distortion were different:In teeth group,the stress was mainly loaded on the canines,and is not uniformly distributed;In aligner group,the stress was more uniformly distributed with bigger loading where closer to the canine.The stress in aligner group was bigger than in teeth group.Only the periodontal ligament stress distribution under 300g force was too large(2.87×10^(-2) MPa).All the other force magnitude was under healthy stress load for the periodontal ligament.Conclusions The Class U elastic of lOOg is sufficient to resist the loss of anterior anchorage and 300g loading on the aligners should be avoided as much as possible since too much pressure may cause damage to the periodontal tissue.

关 键 词：三维有限元 磨牙远移 Ⅱ类牵引 牙周膜等效应力 支抗 

分 类 号：R783.5[医药卫生—口腔医学]