螺旋CT在埋伏多生牙定位诊断和拔除中的作用

The Role of Spiral CT in Diagnoses and Localization of Embedded Supernumerary Tooth

目的:探讨螺旋CT在埋伏多生牙定位诊断中的作用。方法:对9例常规口腔全景片不能清楚判断上颌骨内埋伏牙位置患者行西门子公司Sensation 16 CT检查,取层厚0.75mm,重建层厚0.75mm,螺距1.0。所得数据经工作站处理,采用多平面重建(multiplane reconstruction,MPR),最大密度投影(maximum intensity projection,MIP),三维表面成像(surface shading display,SSD)。根据取得的CT三维图像顺利拔除埋伏多生牙。结果:9例经螺旋CT扫描取得的图像检查能够清楚地显示埋伏牙多生牙的形态、大小、空间位置及与邻牙的关系。由于手术进路选择正确,平均手术时间30min。所有病例都没有发生牙根和根尖血管损伤的并发症。结论:螺旋CT与全景片和定位片相比较能够更直接、明确地反映埋伏多生牙的位置,为手术治疗提供可靠的依据。

Objective：To explore the role of dental CT in the diagnosis and localization of embedded supernumerary tooth. Methods：Nine patients whose embedded supernumerary tooth＇s location couldn＇t be judged clearly through the orthopantomography were scanned by Siemens Sensation 16, with 0.75 mm collimation, reconstruction interval 0.75mm and pitch of 1.0. Original data was transferred to workstation and processed with multiplane reconstruction （MPR）, maximum intensity projection （MIP） and surface shading display （SSD）. With the help of these three-dimensional images of spiral CT, all of the embedded teeth were extracted smoothly. Results：The images of spiral CT could clearly demonstrate the shape, size, location, eruption o- rientation and relation with adjacent teeth of the embedded supernumerary tooth in all cases. Because of the appropriate opening location, average of operation time was half an hour. Conclusion： Compare with panorama, spiral CT can provide more direct and accurate images of the location of embeded tooth, with the help of these image.