上颌埋伏尖牙CT影像分型系统的建立和分析

目的 利用螺旋CT三维重建技术建立适合上颌埋伏尖牙的影像学分型系统。方法 选择102例上颌埋伏尖牙患者为研究对象，共121颗上颌埋伏尖牙。所有患者均接受标准的螺旋CT扫描，数据均导入MIMICS 10.01软件采用表面遮盖成像法进行三维重建。通过对121颗上颌埋伏尖牙的三维空间位置进行分析建立上颌埋伏尖牙的影像学分型系统。结果 本研究建立了一个上颌埋伏尖牙的三维CT影像学数据库。研究结果显示在X轴方向上，最常见的分型是牙尖近中伴根尖正常。在Y轴方向上，样本中所有埋伏尖牙只存在3种分型即根尖均处于高位，牙尖分别处于高、中、低位。在Z轴方向上，最常见的分型是牙尖和根尖均处于唇侧，约占总数的三分之一。结论 本研究利用螺旋CT建立了一个适合上颌埋伏尖牙的三维影像学分型系统，具有一定的临床诊断价值。

Establishment and analysis of a spiral CT-based classification system for maxillary canine impactions

Objective To establish a 3D image classification system for maxillary canine impactions based on spiral CT.Methods A retrospective sample of 102 subjects with maxillary canine impaction （121 impacted canines） were selected.All subjects received standard CT scans and all data （DICOM files） were reconstructed through MIMICS10.01 by the means of Surface Shaded Display （SSD） to show the 3D position of the impacted canines.Based on the analysis of 121 impacted canines,a 3D CT image classification system for maxillary canine impactions was established.Results A database for 3D CT images of different maxillary canine impactions was established.The data showed that the type of mesial cusp tip with normal root apex of maxillary canine was most common on the X axis while there were only three types on the Y axis which were high root apex with high,middle or low cusp tip of maxillary canine.And the type of buccal cusp tip with buccal root apex of maxillary canine （about 1/3） was most common on the Z axis.Conclusions A 3D image classification system for maxillary canine impactions based on spiral CT was established with certain diagnostic value.