上颌磨牙牙根及根管解剖形态的锥形束CT研究

Cone-beam computed tomography was used for study of root and canal morphology of maxillary first and second molars

目的：通过锥形束CT（cone-beam computed tomography,CBCT）图像分析上颌恒磨牙牙根和根管的解剖形态.方法：对2012年5～9月因牙体牙周疾病行CBCT检查的患者资料进行回顾性分析.健康、未经过治疗、发育良好的630颗上颌第一磨牙、519颗上颌第二磨牙被纳入本研究,分析每颗磨牙的牙根数目、根管数目及根管形态,采用Venucci分类法对根管构型进行分类描述.将Vertucci Ⅰ型计为常规形态,其他类型计为变异形态,计算变异率.结果：上颌第一磨牙中,2.38％有2个独立牙根,97.14％有3个牙根,0.48％有4个牙根.上颌第二磨牙中,10.41％为单根牙,15.22％有2个牙根,73.60％有3个牙根,0.77％有4个牙根.存在3个牙根的612颗上颌第一磨牙中,近中颊根变异率为30.88％;存在3个牙根的382颗上颌第二磨牙中,近中颊根变异率为13.87％.结论：CBCT精确地显示了关于牙根及根管数目与形态的三维图像,这为疑难根管治疗提供了直观而准确的信息.

Objective：To investigate the root and canal morphology of maxillary first and second molars by using cone-beam computed tomography （CBCT）.Methods：The data of patients who underwent the CBCT scan for dental or periodontal diseases between May and September 2012 were analyzed retrospectively.In the study,630 maxillary first molars,519 maxillary second molars which were well-developed and without treatment were included.The number of roots,the number of root canals,and the canal configuration according to Vertucci＇ s classification were determined.The vertucci type Ⅰ was regarded as the conventional form.Other types were the variation forms and the mutation rate was calculated.Results：2.38％ of the maxillary first molars and 15.22％ of the maxillary second molars had 2 separated roots; 97.14％ of the maxillary first molars and 73.60％ of the maxillary second molars had 3 roots; 10.41％ of the maxillary second molars had one single root ; 0.77 ％ of the maxillary second molars had 4 roots.In 612 3-rooted maxillary first molars,additional canals were found in 30.88％ of the mesiobuccal （MB） roots.In 519 3-rooted maxillary second molars,additional canals were found in 13.87％ of the MB roots.Conclusion：CBCT scans show the root and canal anatomy accurately,with the potential of improving the outcome of endodontic treatment.