Investigation of correlation between root morphology of mandibular second molars in panoramic images and cone beam computed tomography

Abstract

Abstract Background: Knowing the shape of the root and the root canal system is essential for the success of the surgical and non-surgical treatment of the root canal, however; it is difficult to judge root and root canal anatomy from two-dimensional radiographs . The aim of this study is to investigate correlation between root morphology of the mandibular second molars in panoramic view and the root type of these teeth based on Cone Beam Computed Tomography (CBCT) images. Methods: In this study, 1231 CBCT scans of the second mandible molars were selected from archives of a private radiology clinic from October 2018 to March 2021, and panoramic images reconstructed from CBCT images. The root morphology of the second mandible molar was classified on panoramic image in type 1,2,3,4,5. Root pattern in cross-section of CBCT image was classified into three types of single, double and c-shape.Correlation between root morphology in panoramic image and CBCT was analyzed with Chi-Square test and significance level was 0.05. Results: 62.7% of the second mandibular molars were type1, 97.3% of them had double pattern in cross-section of CBCT.28.6% of the samples were type2, which showed 92.6% double pattern. 3.9% of them were type3, 47.9% had c-shape pattern.0.9% of them were type4, 45.5% of them showed single pattern.3.8% of teeth were type5, 76.6% had single pattern. The prevalence of c-shape canals was higher in women and most c-shape canals showed C3 pattern. Conclusion: There was a strong correlation between the root morphology in panoramic image and root canal pattern in the axial section of the CBCT images. According to this study, if the second mandibular molar has a type3 morphology in the panoramic image, it may have a c-shape canal with a high probability.