三维CT定位在上颌阻生尖牙拔除中的应用

Application of 3-D computerized tomography in the management of impacted cuspid extraction

目的:应用CT对拔除上颌埋伏阻生尖牙进行准确定位,以减少拔除时的盲目性,避免对邻牙及周围组织的损伤。方法:对30例临床上拔除较为困难的埋伏阻生尖牙,拍摄X线全景片和定位片进行分析,并对其中22例较难判断的病例加摄三维CT进行定位,判断埋伏阻生尖牙是否位于唇侧或腭侧,或穿行于唇、腭侧间。结果:30例尖牙埋伏阻生病例,仅8例通过全景片加定位片能较准确地判断其位于唇侧或腭侧,其余22例因移动不明显而难以判断,在通过加摄三维CT后才能准确判断尖牙阻生的位置及与邻牙间的位置关系。结论:三维CT定位准确性高,可避免全景片和定位片因重叠及平面效果而造成的判断错误,减少手术进路的盲目性,缩短手术时间,避免手术中对周围骨组织和邻牙的损伤。

PURPOSE： Computerized tomography was applied in the management of impacted cuspid extraction with the purpose of reducing the surgical risk and protecting the adjacent teeth as well as the surrounding tissues from injury. METHODS： Preoperative panoramic and localization radiographs were performed in 30 patients with impacted cuspids, and further computerized tomography was added in 22 out of the 30 patients to localize the difficult impacted cuspids and their impacted direction. RESULTS： The exact location and impacted direction of the impacted cuspids were determined only using panoramic radiograph and localization radiograph in 8 patients. In the remaining 22 patients ,the panoramic and periapical films were not enough ; with 3-D computerized tomography, the exact location and impacted direction of the difficult impacted cuspids and their relationship with the adjacent teeth and surrounding tissues were determined. CONCLUSIONS： The 3-D computerized tomography can be used to locate the impacted cuspid exactly, especially for the difficult impacted cuspids. The preoperative application of 3-D computerized tomography is useful to reduce the surgical risk and protect the adjacent teeth and surrounding tissues from injury. Supported by Shanghai Leading Academic Discipline Project（Grant No. Y0203）.