川渝地区人群下颌磨牙牙根及根管解剖形态的锥形束CT分析

Cone Beam CT Analysis of Anatomical Morphology of Root and Root Canals of Mandibular Molars in Sichuan and Chongqing Area

目的采用锥形束CT分析研究川渝地区人群下颌第一磨牙和第二磨牙的牙根与根管解剖形态,以为临床根管治疗提供参考。方法调取乐山市人民医院口腔科和重庆医科大学附属口腔医院放射科因治疗需要而拍摄的下颌磨牙CBCT影像从中选择根尖孔发育完全、未行牙髓治疗、无桩或冠修复的下颌恒磨牙影像资料数据,详细记录下颌磨牙的牙根数目与形态,并采用Vertucci分类法统计分析其根管形态。结果本研究纳入845例患者共1370颗下颌第一磨牙和1412颗下颌第二磨牙。其中,下颌第一磨牙的近中根均为单根,远中舌根的发生率为23.50%;其近中根常见根管构型为VertucciⅣ型(64.31%)和Ⅱ型(25.33%);远中单根的下颌第一磨牙以Ⅰ型(54.48%)和Ⅳ型(27.96%)根管为主,而对于远中双根的下颌第一磨牙,94.10%的远颊根和所有的远舌根为Ⅰ型单根管。在下颌第二磨牙中,36.69%为不完全融合的C型牙根,仅0.42%的下颌第二磨牙拥有三个牙根。下颌第二磨牙C型根管的发生率为33.85%,两侧C型根管的发生率差异无统计学意义(P>0.05)。结论川渝地区人群下颌磨牙牙根及根管形态多样,变异性较大;锥形束CT较其他影像检查方法在研究牙根和根管形态方面具有明显优势,能够为根管治疗提供参考。

Objective To study the anatomy of root and root canal of mandibular first and second molars in Sichuan and Chongqing by cone-beam CT to provide reference for clinical root canal treatment.Methods The CBCT images of mandibular molars were taken from the Department of Stomatology of Leshan People’s Hospital and the Department of Radiology of Affiliated Stomatological Hospital of Chongqing Medical University.The image data of mandibular permanent molars with complete apical foramen development,without pulp treatment,without post or crown restoration were selected.Permanent molar image data was used to record the root number and morphology of mandibular molars in detail,and the root canal morphology was statistically analyzed using Vertucci classification.Results A total of 1370 mandibular first molars and 1412 mandibular second molars were included in this study.Among them,the mesial roots of the mandibular first molars were all single roots,and the incidence rate of the distal and middle tongue roots was 23.50%.The common root canal configurations of the mesial roots are Vertucci type Ⅳ(64.31%) and typeⅡ(25.33%).The mandibular first molars of the roots are mainly type Ⅰ(54.48%) and type IV(27.96%) root canals,while for the mandibular first molars of the double middle roots,94.10% of the distal buccal roots and all the distal tongues are Ⅰ Type single canal.Among the mandibular second molars,36.69% were incompletely fused C-type roots,and only 0.42% of the mandibular second molars had three roots.The incidence of C-type root canals in mandibular second molars was 33.85%,and there was no significant difference in the incidence of C-type root canals on both sides(P>0.05).Conclusion The root and root canal morphology of mandibular molars in Sichuan and Chongqing are diverse and variability.Cone beam CT has obvious advantages over other imaging methods in studying root and root canal morphology,which could provide a reference for root canal treatment.