[摘要]目的研究磁力扩弓(MPE)后上颌牙列三维方向的位置变化。方法选取15例经MPE的患者，应用螺旋CT获得治疗前后的三维数据模型，测量上颌牙列各标志点的三维位置和角度的改变，并采用配对符号秩检验对比分析各项数据。结果MPE治疗前后上颌牙列位置在矢状向、垂直向和水平向上均发生了改变。第一磨牙和第一前磨牙发生了颊倾和整体移动；上颌最大扩宽位置是在第一前磨牙区；上颌中切牙发生了向下和向前的移动。结论螺旋CT能够详细测量上颌牙列在MPE前后的位置变化，为进一步研究MPE的机制和特点提供了依据。

    [关键词]磁力扩弓；三维测量；螺旋CT

    [中图分类号]R 783.5[文献标志码]A[doi]10.3969/j.issn.1673-5749.2012.04.004

    Three-dimensional measurement of upper arch after magnetic palatal expansion using spiral CTMa Qiaoling1, Li Huang1, Wang Tiemei2, Huang Gang3.(1. Dept. of Orthodontics, The Affiliated Stomatological Hospital of Medical College, Nanjing University, Nanjing 210008, China; 2. Dept. of Oral Radiology, The Affiliated Stomatological Hospital of Medical College, Nanjing University, Nanjing 210008, China; 3. Center of Laboratory Technology, The Af-filiated Stomatological Hospital of Medical College, Nanjing University, Nanjing 210008, China)

    [Abstract]ObjectiveTo investigate upper arch changes after magnetic palatal expansion(MPE)in three-dimensional direction. Methods15 patients treated with MPE were included in the study. Spiral CT images were used to evaluate three-dimensional changes of upper arch, and the changes of upper arch points were measured. The results were analyzed based on pairs signed rank test method. ResultsUpper arch and teeth move in three-dimensional changed after MPE. Upper first molars and first premolars had buccal inclination and bodily movement. The maximum expansion was observed between upper first premolars, and upper central incisors moved downward and forward. ConclusionSpiral CT is useful in the three-dimensional evaluation of maxilla after MPE and provided the first evidence to study mechanism of MPE. ......