上颌前方牵引方向的有限元分析  

A three-dimensional 3-D finite element study on direction of maxillary protraction

作　　者：林伟就[1] 邹敏[1] 刘小兰[1] 郑玉莹[1] 

机构地区：[1]西安交通大学口腔医院正畸科,陕西西安710004

出　　处：《上海口腔医学》2010年第5期475-479,共5页Shanghai Journal of Stomatology

摘　　要：目的:建立并使用上颌发育不足三维有限元模型,研究不同前方牵引方向对颅上颌复合体的影响,以期为上颌前方牵引的临床应用提供理论依据。方法:选择1名9岁上颌骨发育不足女性志愿者,采用螺旋CT扫描、数据传输与转录、Mimics10.0软件建立颅上颌复合体的三维有限元模型,利用ANSYS10.0软件,在上颌尖牙处施加与水平面呈-20°～50°的前方牵引力,大小为5N,分析颅上颌复合体的位移变化和内部应力分布。结果:垂直方向上,当牵引角度为-20°～30°时,颅上颌复合体呈逆时针旋转,且随着角度的增加而减小;30°～40°时,垂直向位移为零;≥40°时,颅上颌复合体顺时针旋转,且随角度的增加而增加。水平方向上,牵引角度在-20°～50°时,颅上颌复合体前移,且随着角度增加而减小;0°位移最大。近中方向上:颅上颌复合体及上颌牙弓有向近中位移的趋势,且随牵引角度增大而减小。随着角度的增大,最大主应力呈现递增趋势,范式应力先减后增;当牵引角度大于10°时,最大主应力和范式应力均递增,且递增速度较快。结论:当上颌前方牵引角度与水平面呈30°～40°时,颅上颌复合体平动;大于此范围,可能出现深覆,反之有开的风险。牵引角度越大,颅上颌复合体前移量越小,应力越大。PURPOSE：To offer a scientific basis on the direction of maxillary protraction by establishing and using three-dimensional finite element model （FEM） of cranio-maxillary complex.METHODS：Using thin-slice high resolution CT scanning and digital image transfer and transcription, in combination with Mimics 10.0 software, a three-dimensional FEM of cranio-maxillary complex of Class Ⅲ malocclusion （maxillary retrusion）,whose modeling sample was a 9 years old female, was established.Then 8 directions between-20°and 50° against horizontal plane of anteriorly-directed extraoral forces （5N） were added in the area of maxillary canine.The displacement and stress distribution in the cranio-maxillary complex were analysed by using ANSYS 10.0 software.RESULTS：Vertically, when the protraction angle was less than 30°, the cranio-maxillary complex showed anticlockwise rotation.And the displacement showed decrease with increasing of angle.When 30°to 40°, the perpendicular displacement of any marker point was zero.When the protraction angle was greater than 40°, it showed clockwise rotation.Horizontally：When the protraction angle was between-20° and 50°, the maxillary moved forwards.And the displacement got its top when the angle was zero.Medially, the cranio-maxillary complex and maxillary dental arch had the trend of medial movement.With the angle increasing, the displacement was decreased,and the major principal stress was increased.Von Mises stress was decreased and then increased.When the protraction angle was greater than 10°, these stresses showed increase.CONCLUSIONS：When the protraction angle is between 30° and 40°, the cranio-maxillary complex shows movement without any rotation.The risk of deep-bite may be present while the angle diminished.On the other hand,there is the risk of open-bite.The greater the protraction angle, the less of the craniomaxillary complex advances, but the stress increases.With increase of the protraction angle, the antedisplacement of cranio-maxillary complex decr

关 键 词：颅上颌复合体 上颌发育不足 三维有限元 上颌前牵引 

分 类 号：R783.5[医药卫生—口腔医学]