正畸滑动关闭牙间隙两种方法的三维有限元分析  

Comparison between one-step and two-step space closing methods of sliding mechanics using three-dimensional finite element

作　　者：韩耀辉[1] 牟兰[1] 徐庚池[1] 杨艺强[2] 葛振林[1] 

机构地区：[1]兰州大学口腔医学院正畸科,730030 [2]宁夏医科大学附属口腔医院正畸科

出　　处：《中华口腔医学杂志》2015年第3期182-185,共4页Chinese Journal of Stomatology

摘　　要：目的 通过三维有限元方法分析一步法与两步法滑动关闭牙间隙时前牙的移动趋势,探索组牙控根移动方法,为正畸临床提供参考.方法 采用锥形束CT扫描1名个别正常（牙合）志愿者,获得包括上颌骨、牙齿在内的图像数据,导入Mimics软件分离牙齿、牙周膜、上颌骨,导入Pro/Engineer 软件进行实体化处理,获得包含6颗前牙的一步法模型和包含4颗前牙的两步法模型.应用Abaqus 有限元分析软件模拟滑动法,分别在牵引钩加力高度为2、4、6、8、10、12、14 mm时加载1.47 N力,对比两种模型上颌前牙的唇舌向初始位移,分析组牙控根平移的牵引钩加力高度,比较两种模型滑动法关闭牙间隙时牙齿初始位移.结果 当牙齿控根平移时,两步法中切牙和侧切牙的初始位移分别为29.26×10^-6和46.76×10^-6mm,一步法中切牙和侧切牙的初始位移分别为15.75×10^-6和23.18×10^-6 mm,即相同加力条件下两步法的前牙初始位移约为一步法同名前牙的2倍;一步法尖牙冠根无法获得相同的位移.结论 两步法滑动关闭牙间隙时前牙更易控根移动;与一步法相比,两步法滑动关闭牙间隙产生的初始位移更多.To construct a three-dimensional finite element model comparing between one-step and two-step methods in torque control of anterior teeth during space closure.Methods Dicom image data including maxilla and upper teeth were obtained though cone-beam CT.A three-dimensional model was set up and the maxilla,upper teeth and periodontium were separated using Mimics software.The models were instantiated using Pro/Engineer software,and Abaqus finite element analysis software was used to simulate the sliding mechanics by loading 1.47 Nforce on traction hooks with different heights（2,4,6,8,10,12 and 14 mm,respectively） in order to compare the initial displacement between six maxillary anterior teeth （one-step method） and four maxillary anterior teeth（two-step method）.Results When moving anterior teeth bodily,initial displacements of central incisors in two-step method and in one-step method were 29.26× 10^-6 mm and 15.75× 10^-6 mm,respectively.The initial displacements of lateral incisors in two-step method and in one-step method were 46.76× 10^-6 mm and 23.18× 10^-6 mm,respectively.Under the same amount of light force,the initial displacement of anterior teeth in two-step method was doubled compared with that in onestep method.The root and crown of the canine couldn＇t obtain the same amount of displacement in one-step method.Conclusions Two-step method could produce more initial displacement than one-step method.Therefore,two-step method was easier to achieve torque control of the anterior teeth during space closure.

关 键 词：有限元分析 正畸缺隙闭合 牙正畸牵引 

分 类 号：R783.5[医药卫生—口腔医学]