锥束CT、螺旋CT和曲面断层片诊断埋伏牙的对比性研究

Contrastive Investigation on the Diagnosis of the Impacted Teeth of the Cone-Beam CT,Helical CT,and the Panoram- ic Radiograph

目的:比较锥束CT、螺旋CT与传统曲面断层片对埋伏牙诊断的精确性,评价锥束CT和螺旋CT在埋伏牙拔除手术中的诊断价值。方法:选取93名患者的93个完全骨埋伏牙作为研究对象,其中37名患者下颌完全骨埋伏牙,56名患者上颌完全骨埋伏牙。拍摄曲面断层片后,均诊断需要拔除埋伏牙,其中31位患者单纯拍摄曲面断层片,31位患者增加拍摄螺旋CT,31位患者增加拍摄锥束CT。在3组影像上测量埋伏牙大小,及其与预备开窗处骨面距离,根据测量数据进行埋伏牙拔除,手术过程中测量埋伏牙与开窗处骨板距离,埋伏牙拔除后测量牙体大小。对3组患者的各项测量数据进行比较。结果:拍摄螺旋CT和锥束CT的患者离体牙与影片测量的差值显著小于拍摄曲面断层片的患者(P<0.01),拍摄锥束CT的患者离体牙和影片测量的差值小于拍摄螺旋CT的患者(P<0.01)。结论:与二维影像相比,螺旋CT和锥束CT是一种更有效的检查埋伏牙的方法,能更精确埋伏牙在复杂颌骨结构中的位置,有利于埋伏牙的诊断和治疗。

Objective： To investigate and evaluate the difference of the accuracy of the diagnosis of impacted teeth of the Cone--Beam CT, Helical CT, and the Panoramic radiograph. To estimate the technique of Cone--Beam CT and Helical CT for the extraction of the impacted teeth. Methods： Ninety--three patients with thirty--seven im- pacted teeth in maxillary and fifty-- six impacted teeth in mandibular were examined by Panoramic radiograph. Thirty--one impacted teeth were only examined by Panoramic radiograph, thirty--one impacted teeth were exam- ined by Panoramic radiograph and Helical CT, thirty--one impacted teeth were examined by Panoramic radiograph and Cone--Beam CT. The distance between the impacted teeth and the surface, the length and the breadth of the impacted teeth were measured and the data of Cone--Beam CT, Helical CT, and the Panoramic radiograph were compared. Results： With the measurable index, the data between the teeth and the helical CT and Cone--Beam CT were significantly smaller than that of between the teeth and the Panoramic radiograph （P〈0.01）. The data be- tween the teeth and the Cone--Beam CT were significantly smaller than that of between the teeth and the helical CT （P〈0.01）. Conclusion： Comparing with the Panoramic radiograph, helical CT and Cone--Beam CT could be used as an efficient method for the diagnosis of impacted teeth. The accurate positions of impacted teeth can be demon- strated clearly by helical CT and Cone--Bean CT. They might play an important role in the diagnosis and treatment of buried teeth.