上颌第一、第二恒磨牙牙根和根管系统的锥形束CT研究

目的：运用锥形束CT（CBCT）观察中国人群双侧上颌第一、第二磨牙的牙根和根管系统的解剖形态,为临床根管治疗提供依据。方法：选择200名患者的双侧上颌第一、第二恒磨牙（上颌第一恒磨牙354颗、上颌第二恒磨牙360颗）的CBCT扫描数据,使用NNT软件分析上颌第一、第二恒磨牙的牙根数、根管数、根管分型以及双侧对称情况。结果：上颌第一、第二磨牙主要为三根（99.44%和84.44%）。上颌第二磨牙的单根和双根较多见（15.28%）,其根管系统形态复杂,在根尖区有融合趋势。上颌第一磨牙的根管系统主要为3根四根管（78.97%）。上颌第二磨牙的三根管和四根管发现率接近（分别为47.37%和51.64%）。上颌第一磨牙的近颊根管系统主要根管分型为：Ⅳ型（57.79%）、Ⅱ型（19.83%）和Ⅰ型（15.58%）。上颌第二磨牙的近颊根管系统主要根管分型为：Ⅰ型（48.14%）、Ⅳ型（30.43%）和Ⅱ型（17.39%）。上颌第一、第二磨牙的远颊根和腭根主要为单根单根管,存在少量和罕见的变异。上颌第一、第二磨牙近颊根的根管数目和根管分型左右对称。结论：上颌第一磨牙近颊根管系统变异普遍存在,MB2根管为其主要的变异形式。上颌第二磨牙牙根数目和根管形态变异类型多,单根牙和双根牙的根管走向复杂多变。CBCT可以为识别根管形态提供准确依据。

Study of Root and Canal Morphology of Maxillary First And Second Molars Evaluated By Cone Beam Computed Tomography

Objective：To investigate variations in root canal configuration of the maxillary first and second molar teeth using cone-beam computed tomography（CBCT）.Methods：A total of 200patients with healthy,untreated,well-developed maxillary first and second molars were envolled.Radiographic examined by CBCT was conducted as part of their routine examination.Over all,354maxillary first and 360maxillary second molar teeth were examined in vivo by CBCT.The number of roots,the number of canals per root,the canal configuration and symmetry of bilateral canal classification were recorded.Results：99.44%of maxillary first molar teeth had three separate roots,Most of them had four canals.When the MB2canal was present,57.69% and 19.83% of MB roots had Type IV andⅡcanal configurations,respectively.Most of distobuccal and palatal roots had Vertucci Type I canal configurations.Of 360maxillary second molars,3.8% had one root,11.39%two roots and 84.44%three roots.47.37%and 51.64%of these three-root-teeth had three or four canals,respectively.Of the MB roots,48.14%had one canals.When the MB2canal was present,30.43%,and 17.39%of MB roots had type IV and II canal configurations,respectively.80%and 63.01% of maxillary first and second molars had bilateral canal sysmmetry in configuration of MB root canal,respectively.The symmetry rate of maxillary first molar was higher than maxillary second molar.Conclusion：Mesiobucccal roots of maxillary molar teeth had more variation in their canal system than the distobuccal or palatal roots.The most common form of the variety was MB2canal.The root canal configuration of the maxillary second molars was more variable than that of the first molars.CBCT could enhance the understanding of root canal anatomy,with the potential of improving the outcome of endodontic treatment.