锥束CT多方式三维重建在上颌埋伏前牙定位中的应用

Comprehensive application of multi-pattern three-dimensional surface reconstruction of cone-beam CT in localizing impacted teeth of anterior maxilla

目的评价锥束CT三维重建在上颌埋伏前牙定位中的应用价值。方法对48例常规拍摄全颌曲面断层片和根尖片后不能准确判断埋伏牙的形态、位置及与邻牙关系的患者应用锥束CT进行扫描,再采用最大密度投影法(MIP)、多平面重建(MPR)、容积再现法(VR)获得立体三维图像,显示上颌埋伏前牙的形态、位置及与邻牙关系。运用正畸开辟间隙和外科暴露联合正畸牵引导萌术,结合直丝弓矫治技术,直接粘贴托槽牵引导萌上颌埋伏牙。结果经三种方式重建处理后,48例病例均清晰显示上颌埋伏前牙的形态、位置及与邻牙关系。结论锥束CT多方式三维重建为上颌埋伏前牙定位诊断提供更为客观的依据。

Objective To evaluate the clinical value of three-dimensional surface reconstruction of Cone-beam CT in localizing impacted teeth of anterior maxilla. Methods CBCT was performed in 48 cases whose anterior maxillary im- pacted teeth couldn＇ t be judged clearly through the panoramic radiograph or periapical films. Three-dimensional surface re- construction, including MIP（ maximum intensity projection）, MPR（ multi planar reconstruction）, VR（ volume rendering） was made to display the impacted teeth＇ s shape, location and their relationship with adjacent teeth. Use of orthodontic open gap and surgical exposure together with orthodontics leads and guides impacted teeth, combined with the straight wire technique of direct bond brackets guiding impacted maxillary teeth eruption. Results In 48 cases, the reconstruction im- age including the crown, root, neck and root bifurcation in a three-dimensional form, location and relation with dentition in anterior maxilla. Conclusions Application of multi-pattern three-dimensional surface reconstruction of cone-beam CT is an accurate and effective method to examine impacted teeth of anterior maxilla.