Cone-beam computed tomographic study of root morphology, canal configuration, and bilateral symmetry of mandibular first and second molars in a Qatari population

Introduction: Identifying root and canal morphology are essential for successful endodontic treatment. The study aimed to identify the anatomical variation and the bilateral symmetry of mandibular first and second molars among the Qatari population using cone-beam computed tomography (CBCT). Materials and Methods: Two endodontists reviewed 544 CBCT images of Qatari patients. Age, gender, root morphology, and canal configuration according to Vertucci classification, were recorded. A descriptive analysis was implemented to provide a detailed characterization of the root morphology, root canal configuration, and symmetry between right and left teeth. Kappa agreement analysis was performed to assess the intra- and inter-examiner agreement. Results: A total of 195 mandibular first molar (MFM) and 255 mandibular second molar (MSM) were included in this study. The most commonly observed number of roots in both molars was two in 96.4% of MFMs and 92.9% of MSMs. The majority of MFMs and MSMs had three canals, 79% and 74.2%, respectively. The most common root canal configuration of the mesial root was type IV, found in 66.5% of MFM and 57.8% of MSM. Type I was the most common root canal configuration of the distal roots in 56.9% of MFM and 87.3% of MSM. The symmetrical analysis revealed a high symmetry in the number of the roots. However, the symmetry of the number of canals per root drops to around 75%. Conclusions: Mandibular first and second molars had predominantly two roots with three canals. Variations such as single, three, or four roots and C-shaped canal morphology were also detected and were associated mainly with mandibular second molars.