Anatomical variations and bilateral symmetry of roots and root canal systems of mandibular first permanent molars in a Saudi Arabian population utilizing cone beam computed tomography

Abstract

<h3>Objective</h3> To evaluate the anatomical variations of the roots and root canal systems and to determine the symmetry between right and left mandibular first permanent molars in a Saudi Arabian population using images derived from cone beam computed tomography (CBCT) scans. <h3>Methods</h3> CBCT scans (with exposure parameters 90 kVp, 5–8 mA, 17.5 s exposure time, and 0.25 mm voxel size with a 170 × 120 mm FOV) were retrieved from the database and axial, coronal, and sagittal sections of the mandibular first molars were examined. The number of roots, number of canals, and type of canal configuration based on Vertucci's classification were recorded. Bilateral symmetry between right and left sides of the same individuals and differences between genders were investigated. <h3>Results</h3> Out of 174 mandibular first molars, 97.1% were two rooted and 2.9% were three rooted (with a distolingual root). In regards to the number of canals, 73% had three, 25.3% had four and 1.7% had two root canals. In teeth with four root canals, 90.9% of the extra canals were in the distal root, while 9.1% were in the extra distolingual root. The most common canal configurations in the mesial and distal roots were type IV (64.9%) and type I (77%), respectively. Symmetrical analysis revealed 100% symmetry in number of roots and 56.4% in number of canals between right and left teeth in the same individual. <h3>Conclusion</h3> An extra root was seen in few cases of mandibular first molars of the studied population. A wide range of canal configurations was noted, with high prevalence of type IV in the mesial root and type I in the distal root. No associations between gender and root anatomy and canal morphology were discovered. Although high bilateral symmetry was found in numbers of roots, it varied with regards to numbers of canals and canal configurations in the same individuals. <b>Statement of Ethical Review</b> Human/Animal subjects were used and this study was approved by an institutional ethics panel