摘要
目的研究无托槽隐形矫治联合Ⅱ类牵引内收上前牙的生物力学特征,比较两种牵引方式的差异。方法基于1个磨牙远中关系、拔除4颗第一前磨牙的病例,建立三维有限元模型,模拟前牙整体内收0.2 mm时的牙位移、受力及牙周膜应力分布。工况1:无牵引;工况2:120 gⅡ类牵引,上尖牙、下第一磨牙矫治器切割牵引钩;工况3:120 gⅡ类牵引,矫治器开窗配合粘接牵引扣于相同牙位。结果Ⅱ类牵引显著增强上前牙舌向及下后牙近移趋势,减少上后牙近移及下前牙舌移。水平向牙受力小。矢状方向,工况2平均有效减少上后牙近移力0.13 N,平均增加下后牙近移力0.31 N,工况3显著增加上尖牙远移力0.40 N和下第一磨牙近移力1.14 N。垂直方向,工况2增加上前牙伸长力平均0.22 N及下第二磨牙伸长力0.20 N;工况3增加上尖牙伸长力0.91 N,减少下第一磨牙压低力0.27 N,减少第二磨牙伸长力0.25 N。3组牙周膜应力分布总体相似,工况3下第一磨牙最大主应力分布范围增大,数值未显著升高。结论工况2更有利于保护上后牙支抗、实现下后牙整体近中移动,工况3显著增加上尖牙伸长力和远移力、下第一磨牙近移力,但未显著增加牙周风险。
Objective To investigate the biomechanical characteristics of clear aligners combined with ClassⅡelastics during retraction of upper anterior teeth,and compare the differences between two traction methods.Methods A case with a molar distal relationship and extraction of four first premolars was selected.The finite element method was applied to analyze tooth displacement,force distribution,and periodontal ligament(PDL)stress during 0.2 mm en-masse retraction of the anterior teeth.Three working conditions were defined:en-masse retraction without elastics(Condition 1),120 g ClassⅡelastics with aligner-cut hooks on upper canines and lower first molars(Condition 2),120 g ClassⅡelastics with aligner windows and bonded buttons on upper canines and lower first molars(Condition 3).Results ClassⅡelastics significantly enhanced lingual movement of the upper anterior teeth and mesial movement of the lower posterior teeth,while reducing mesial movement of the upper posterior teeth and lingual movement of the lower anterior teeth.In the transverse direction,the forces exerted on the teeth in all three conditions were minimal.In the sagittal direction,in Condition 2,the mesial force of the upper posterior teeth was effectively reduced by an average of 0.13 N,and the mesial force of the lower posterior teeth was increased by an average of 0.31 N.In Condition 3,the distal force of the upper canine teeth and the mesial force of the lower first molar were significantly increased by 0.40 N and 1.14 N,respectively.In the vertical direction,In condition 2,the average extrusive force of the upper teeth and the extrusive force of the lower molars were increased by 0.22 N and 0.20 N,respectively.In Condition 3,the upper canine extrusive force was increased by 0.91 N,while the lower molar intrusive force and the second molar extrusive force were reduced by 0.27 N and 0.25 N,respectively.The PDL stress distribution in the three conditions was generally similar.In Condition 3,the maximum principal stress distribution area on the lower first molars expanded slightly,but the magnitude did not increase significantly.Conclusions Condition 2 optimized the lower posterior teeth mesialization through balanced force distribution and protected the upper posterior teeth anchorage.Condition 3 significantly increased extrusive and distal forces on the upper canines and mesial forces on the lower first molars but did not substantially elevate periodontal risks for these teeth.
作者
李振霞
付亦蛟
黄兴太
郑轶刊
侯俊祥
刘超
LI Zhenxia;FU Yijiao;HUANG Xingtai;ZHENG Yikan;HOU Junxiang;LIU Chao(Department of Orthodontics,Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine,College of Stomatology,Shanghai Jiao Tong University,National Center for Stomatology,National Clinical Research Center for Oral Diseases,Shanghai Key Laboratory of Stomatology,Shanghai Research Institute of Stomatology,Shanghai 200011,China;Wuxi EA Medical Instruments Technologies Ltd.,Wuxi 214111,Jiangsu,China)
出处
《医用生物力学》
北大核心
2025年第4期828-835,共8页
Journal of Medical Biomechanics
基金
上海交通大学医学院附属第九人民医院生物样本库项目(YBKA202202)
2022年上海交通大学医学院附属第九人民医院优秀研究型医师培育项目(2022YXYJXYS-LC)。
关键词
无托槽隐形矫治
Ⅱ类牵引
前牙内收
有限元分析
生物力学
clear aligners
classⅡelastics
anterior teeth retraction
finite element analysis
biomechanics
