Study on root and root canal morphology of 792 mandibular first premolars

CHEN Jiajing; CHEN Xiaohua; ZHANG Yan; ZHENG Airong

doi:10.15956/j.cnki.chin.j.conserv.dent.2025.10.005

Abstract：Objective To investigate the root and root canal morphology of mandibular first premolars(MnFPs)using cone-beam computed tomography(CBCT).Methods The CBCT images of 792 MnFPs from 396 patients were reviewed.For each tooth,the number of roots,root canal configurations(Vertucci classification;C-shaped canals reported separately),the position of root canal bifurcation(coronal,middle,or apical third),and the location of radicular grooves were recorded.The differences in root canal configurations between different genders were compared.The symmetry of root canal configurations of left and right teeth and the relationship between the incidence of radicular grooves and root canal configurations were analyzed.Results Among 792 MnFPs,5 teeth had two roots,226 teeth exhibited complex root canal configurations(Vertucci type Ⅱ:n=2;type Ⅲ:n=63;type Ⅴ:n=105;other types:n=7;C-shaped canals:n=49).Among single-rooted teeth with complex root canal configurations,80.54％had canal bifurcations in the middle third of the root.219 single-rooted teeth had radicular grooves,and 97.72％of the radicular grooves were located on the mesial surface or mesial-lingual side of the root.Complex canal configurations were more frequent in males than females(P<0.05).The symmetry rate of root canal configuration of left and right teeth was 88.35％.The prevalence of radicular grooves was related to root canal configurations.Radicular grooves were more prevalent in teeth with complex root canal than in single root canal teeth(P<0.05).Conclusion The morphology of the root and root canal of MnFPs show morphological diversity with substantial bilateral symmetry.Complex canal configurations are more common in males and are associated with radicular grooves.These findings can inform endodontic access design and improve treatment success.