目的探讨正常恒牙及牙槽突的多层螺旋CT(MSCT)表现。方法30例正常牙恒牙与牙槽突应用多层螺旋CT扫描,窗宽3000~5000HU、窗位1200~1500HU进行观察。所有图像数据均进行多平面重建、齿科软件全景重建及三维表面遮盖重建。结果牙各部分无机物含量不同而在MSCT图像上显示为密度不同的多层结构,由高到低分别为牙釉质、髓周牙本质、外周牙本质与牙骨质、牙髓。牙周膜位于牙周呈低密度影,厚度均匀。牙槽突骨皮质连续,骨小梁走行呈线状及网状。结论MSCT检查可以清晰显示恒牙及牙槽突的结构,多平面重建及齿科软件全景重建及三维表面重建有助于其相邻关系的判断。 Objective To investigate the multi-slice spiral CT (MSCT) findings of normal permanent teeth and alveolar processes. Methods Thirty patients with normal dentition and alveolar process were examined by multislice spiral CT with window width of 3000-5000HU and window level of 1200-1500HU. All image data were reconstructed with multiplanar reconstruction, panoramic reconstruction of dentistry software and reconstruction of 3D surface coverings. Results The results showed that the content of inorganic components in different parts of the teeth showed different densities on the MSCT images, ranging from enamel, periapical dentin, peripheral dentin, cementum and dental pulp. Periodontal ligament in the periodontal showed a low density, uniform thickness. Alveolar bone cortical continuity, trabecular tracts were linear and reticular. Conclusion MSCT can clearly show the structure of permanent teeth and alveolar process, multiplanar reconstruction and panoramic reconstruction of dental software and 3D surface reconstruction contribute to the judgment of the adjacent relationship.