改良型Ⅱ类颌间牵引致下颌支抗牙受力变化分析  

Stress analysis of mutated Class Ⅱ intermaxillary traction system to mandibular anchorage teeth

作　　者：程自力[1] 刘长庚[1] 莫业跃[1] 赵殿才[1] 尹高权[1] 黄小芳[1] 

机构地区：[1]佛山市南海区第二人民医院口腔科,广东佛山528251

出　　处：《广东牙病防治》2012年第5期264-268,共5页Journal of Dental Prevention and Treatment

基　　金：佛山市卫生局医学科研立项(2010269)

摘　　要：目的研究改良型Ⅱ类颌间牵引的支抗磨牙受力情况及移动特点,分析其相关影响因素。方法参考Typodont模型原理,设计制作出结构简化的实验牙受力、移位测量装置。实验对象依受力点、受力大小及受力角度不同分为4个实验组,每组3颗样本牙。1组:受力点位于下颌实验牙近中舌侧尖,力值150 g;2组:受力点位于下颌实验牙远中舌侧尖,力值150 g;3组:受力点位于下颌实验牙近中舌侧尖,力值100 g;以上3组上颌受力点均位于上颌尖牙,施力角度约30°。4组:受力点位于下颌实验牙近中舌侧尖,力值100 g,上颌受力点位于上颌双尖牙,施力角度约60°。选取实验牙近中颊尖、远中尖、近中舌尖、远中舌尖最高点为固定标志点,以测量装置上的基准点线为参照点线,测量实验前后下颌实验牙标志点与基准点线间的距离,对所得数据进行t检验分析。结果 4组下颌实验牙在牵引力作用下均有明显的近中向及颊向移位,同时伴牙合向伸长。近中向位移值范围为0.50～3.33 mm,颊向位移值范围为2.67～6.17 mm,垂直向位移值范围为0.22～4.00 mm。位移大小与牵引力大小有关,1组和3组差异有统计学意义(P<0.05)。牵引力角度的变化可影响实验牙移动模式,角度增加,实验牙以颊向及牙合向移位为主,同时冠远中向旋转减轻。结论改良型Ⅱ类颌间牵引力引起下颌实验牙三维移动,以近中及颊向移位为主,受力点的位置、牵引力的大小与角度可影响支抗牙的移动模式。Objective To explore the stress and movement feature of anchorage molars result from mutated Class Ⅱ intermaxillary traction,and to analyse the related influencing factors.Methods Refers to the Model Typodont＇s principle and the simplified appliances to measure the experimental teeth mechanical force and movement were designed and made.According to the differences of the loading points,strength and angle of the force,the objective teeth were separated into four experimental groups,and each one had three samples.GroupⅠ： loading points were at the level of mesiolingual cusp;the upper loading points were at the level of maxillary canine teeth;the force was 30 degree and 150 gram.GroupⅡ： loading points were at the level of distolingual cusp,upper loading points were at the level of maxillary canine teeth;the force was 30 degree and 150 gram.Group Ⅲ： loading points were at the level of mesiolingual cusp,upper loading points were at the level of maxillary canine teeth;the force was 30 degree and 100 gram.Group Ⅳ： loading points were at the level of mesiolingual cusp,upper loading points were at the level of maxillary premolar;the force was 60 degree and 100 gram.The mesiobuccal cusp,mesiolingular cusp,disdal cusp and distolingular cusp＇s highest points of the experimental teeth were chosen as fixed index points,and the benchmark lines of the measure equipment as the reference point lines,and then the distances between index points and benchmark lines before and after the experiments were measured.Results Under the traction force,all the testing teeth showed clear mesial movement（the value of dot a and b,which represents the mesial displacement,was 0.50 mm and 3.33 mm respectively） and buccal movement（the value of dot c and d,which represents the buccal displacement,was 2.67 mm and6.17 mm respectively）,and were occlusally elongated（the value of dot g and h,which represents the vertical displacement,was 0.22 mm and 4.00 mm re-spectively）,the extents of movement depending on the force＇s

关 键 词：Ⅱ类颌间牵引 Ⅱ类牵引力 支抗磨牙 

分 类 号：R782.12[医药卫生—口腔医学]