后牵引恒河猴上颌骨矫形实验中螺旋CT三维重建技术的应用

The Application of Spiral CT Three-demensional Reconstruction for Backward Traction of Maxilla Orthopedic Experiment on Rhesus Monkeys

目的探讨螺旋CT三维重建技术在后牵引恒河猴上颌骨矫形实验研究中的应用及测量三维坐标系的建立.方法采用颧骨种植体支抗后牵引上颌骨的动物模型,行螺旋CT扫描及三维重建,以鼻额缝的前上部中点(N点),蝶鞍前壁上后缘中点(S’点),枕骨大孔前缘下后中点(Ba点)为基准点建立以S’点为原点的测量三维坐标系.用MIMICS软件生成SSD三维模型,分别用Unisight软件在MPR相下、MIMICS在SSD相下获得各点原始三维坐标值,通过数学计算得到各测量点在测量三维坐标系下的坐标值.结果建立了后牵引上颌骨矫形实验中动物头颅的测量三维坐标系,MIMICS软件能精确、快捷地重建CT扫描后的三维图象,使矫治前后的头颅数据模型可以在此坐标系下重叠,进行对比研究.结论测量三维坐标系的建立能准确反映实验动物在矫形力作用下颅面结构三维向的改变,也为CT进一步用于动物基础研究提供一种方法.

Objective To discuss the application of spiral CT three-demensional reconstruction for backward traction of maxilla orthopedic experiment on rhesus monkeys and establish the three-demensiona] reference frame. Methods We used an animal model of backward traction and set up a three-dimensional reference frame, which is based on point ＂S＇ ＂ （the media point of the upper rear brim of the anterior wall of pituitary fossa） , point ＂N＂ and point ＂Ba＂ and of which point ＂S＇＂ is origin. The SSD model was made by MIMICS and datas of all points were got by MPR and SSD through Unisight and MIMICS respectively. The value of the reference frame was transfered by mathematic calculating. Results The three-demensional reference frame more suitble for monkeys under orthopedic forces was established and the three-demensional model was accurately reconstructed by MIMICS. Conclusion The cranioficial three-dimensional changes of monkeys can be measured and a new way can be provided for animal reaserch by this method using spiral CT.