上颌第二磨牙根管解剖形态的初步研究

目的: 利用透明牙技术和锥形束CT(cone-beam computed tomography, CBCT)体层扫描技术对上颌第二磨牙根管解剖形态进行研究, 比较CBCT对根管形态的识别与透明牙有无一致性。方法: 对50颗离体牙进行CBCT扫描, 数据导入用计算机软件, 根据Vertucci根管分型, 记录每颗离体牙每个牙根的根管分型。用改良根管染色技术对离体牙进行透明牙制作, 根据Vertucci分类, 将离体牙按每个牙根进行根管类型统计。采用SPSS17.0软件包对所得数据进行统计学处理。结果: 经过对透明牙的观察, 上颌第二磨牙远中颊根和腭根根管形态以Ⅰ型(1-1)为主, 发现新的根管分型(3-2-2)。近颊根的变异比较复杂, 主要以Ⅰ型居多(54.4%), Ⅱ型(2-1)、Ⅳ型(2-2)、Ⅴ型(1-2)和Ⅵ型(2-1-2)均有发生。近颊第二根管发生率为41.3%;经一致性检验, CBCT与透明牙在根管分型上具有一致性(P<0.001)。结论: 上颌第二磨牙根管解剖形态复杂, 尤其近颊根根管类型多变。CBCT与透明牙对根管的识别具有一致性, 其提供的三维影像技术对临床工作具有指导意义。

Preliminary study on root canal morphology of maxillary second molars

PURPOSE: To investigate the root canal morphology and anatomy of maxillary second molars using transparent tooth technique and cone-beam computed tomography (CBCT), and explore the consistency of 2 methods in identifying root canal configurations and morphology. METHODS: Fifty extracted maxillary second molars were scanned by CBCT and analyzed using assistant software. Root canal configurations of each root were identified based on Vertucci's classification and recorded. All transparent teeth samples were made with modified root canal staining technique, and the root canal configurations of each root were classified based on Vertucci's classification. The results were analyzed statistically with SPSS17.0 software package. RESULTS: According to transparent tooth technique, typeⅠ was the most common configuration in distobuccal root and palatal root. An additional configuration type 3-2-2 was found in the present study, which was not included in Vertucci’s classification. The wide variety of canal systems was seen in the mesiobuccal root. TypeⅠconfiguration was most prevalent(54.4%), followed by TypeⅡ, Ⅳ, Ⅴ, Ⅵ. The prevalence of second canal in mesiobuccal root (MB2) was 41.3%. The results of canal morphology and configuration were consistent between transparent tooth technique and CBCT. CONCLUSIONS: Maxillary second molars have the most complex root and canal morphology, especially for the mesiobuccal root. For identifying root canal and root anatomy, CBCT can be used as an alternative to transparent tooth technique in clinical practice. The application of 3D reconstruction based on CBCT helps us to visualize the root canal anatomy.