螺旋CT测量快速扩弓后上颌骨位置三维变化

Three-dimensional changes of maxilla after rapid maxillary expansion

目的观察快速扩弓(RME)治疗前后上颌骨位置三维方向的变化。方法使用螺旋CT,测量10例恒牙患者RME治疗前后上颌骨各测量点的位置和角度改变。使用配对符号秩检验对比分析各项数据结果。结果RME治疗后上颌骨各测量点均向前、向下移位。代表硬腭的PNS′-ANS连线在正中矢状平面上的投影顺时针旋转0·9°,而代表上颌骨腭突的PNS′-ANS在正中矢状平面上投影的角度变化不明显。冠状平面观,两侧上颌骨下部扩开量较上部大,二者相互向外侧呈楔形倾斜。腭中缝呈前后较小中间稍大的纺锤形扩大。结论RME治疗前后上颌骨位置在矢状向、垂直向和水平向上均发生了相应的改变。应用螺旋CT可以对这种三维位置变化进行详细研究。

Objective To investigate three-dimensional changes of maxilla after rapid maxillary expansion（RME）. Methods Ten patients treated with RME were included in the study. Spiral CT images were used to evaluate three-dimensional changes of the maxilla. A three-dimensional reference frame was set up. Results ①ANS, PNS＇and PNS displaced downward and forward. ANS-PNS plane rotated clockwise in the mid-sagittal plane. ANS-PNS＇plane, which represents the real position of maxilla, was not changed in the mid-sagittal plane. The palatal suture was expanded in taper shape and two halves of the maxilla rotated in the frontal plane. ②The maxillary suture was opened wider in the middle and narrower at both ends, which was like a spindle. Conclusions Three-dimensional changes were found after RME treatment. Spiral CT was useful in the three-dimensional evaluation of maxilla.