无托槽隐形矫治技术生物力学效应的有限元法研究  

Biomechanical effects of bracketless appliance technology:a finite element method study

作　　者：唐娜[1] 赵志河[1] 王军[1] 刘展[2] 田杰[3] 

机构地区：[1]四川大学华西口腔医院正畸科口腔疾病研究国家重点实验室,成都610041 [2]四川大学生物力学工程实验室,成都610041 [3]北京时代天使生物科技有限公司上海分公司,上海200135

出　　处：《医用生物力学》2010年第6期399-405,共7页Journal of Medical Biomechanics

摘　　要：目的初步构建无托槽隐形矫治技术的生物力学基础研究模型,分析该矫治体系的应力分布情况,为优化该技术的临床应用提供依据。方法基于CT扫描1例成人干颅标本的影像数据,运用Mimics及ABAQUS软件建立上颌牙列前牙段的无托槽矫治技术三维有限元模型,包括牙颌组织模型、无托槽矫治器模型以及两者的装配,采用非线性有限元法分析牙体牙周组织及矫治器本身的应力分布情况,并与传统固定矫治加载相比较。结果无托槽矫治器作用下,牙周组织瞬时应力约为固定矫治加载时的50～500倍;矫治牙互相影响,矫治牙的移动趋势与预先设计之间相比有差异,拟近远中向平移的尖牙表现为倾斜移动趋势;矫治器本身有应力集中现象,但是最大应力峰值小于材料的弹性极限53.1 MPa。结论无托槽矫治器作用下牙周瞬时应力很大,矫治器在正畸牙近远中移动过程中的三维控制能力有限,不能完全代替传统固定矫治器,建议临床上使用该技术时通过应用附件、改进矫治器材料力学性能等手段,来加强对正畸牙移动的控制。Objective To develop an initial numerical model for bracketless appliance technology,and to analyze the biomechanical effects.To provide the fundamental basis to optimize the clinical application of bracketless ap-pliance technology.Method A 3D numerical model of a dry skull was developed from sequential computed tomography（CT） scan images taken at 0.5-mm intervals by using Mimics and ABAQUS software.This model consisted of three parts： a dento-maxillary model of upper anterior section,a matching bracketless appliance model,and their assembly to simulate orthodontic force stressed by bracketless appliance.The nonlinear finite el-ement method（FEM） was used to analyze the instant biomechanical effects.As the control group,the same dento-maxillary model was loaded to simulate fixed appliance working pattern.Results The instant dento-perio-dontal stress with bracketless appliance loading was much higher than that with fixed appliance working pattern by 50 ～ 500 times.With bracketless appliance loading,the tendency of tooth movement wasn’t exactly performed as planned with orthodontic teeth tending to affect each other.The canine designed to do mesiodistal translation ten-ded to do tipping movement rather than bodily movement.Bracketless appliance itself performed stress concen-tration mainly in places of great deformation,but the maximal stress was less than its elastic limit of 53.1 MPa.Conclusions In this study,bracketless appliance loading performed unexpected high instant stress on dento-periodontal tissue,with limit in controlling tooth movements.The bracketless appliance is not suggested to re-place the traditional fixed appliance.This study suggested bracketless appliances should be designed more rea-sonable,and the material of Anglealignappliances used should be further improved,to enhance the control oforthodontic tooth movement.An ideal material for the bracketless appliance was expected to perform smaller e-lastic modulus,higher elastic limit and better stress relaxation.

关 键 词：隐形矫治器 有限元方法 生物力学 弹性模量 应力分布 

分 类 号：R318.01[医药卫生—生物医学工程]