螺旋CT测量快速扩弓后上颌骨位置三维变化

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。

Three-dimensional changes of maxilla after rapid maxillary expansion

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: (1) ANS, 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. (2) The 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.