Evaluation of the Frequency and Anatomy of Radix Entomolaris and Paramolaris in Lower Molars by Cone Beam Computed Tomography (CBCT) in Northern Iran, 2020-2021: A Retrospective Study

Introduction and objective: The presence of an additional root, known as a radix, in the lower molars is of significant importance in the context of root canal therapy since it has the potential to contribute to treatment failure. Furthermore, it is imperative to take this circumstance into consideration when doing tooth extraction using a radix. The present study investigated the anatomical characteristics and prevalence rates of radix entomolaris and paramolaris in mandibular molars using cone beam computed tomography. Materials and methods: Cone beam computed tomography scans of the lower molars of 376 patients were processed through Newtom’s NNT viewer software. Radix type, radix root canal length, radix root curvature, Vertucci's classification of the canal, and gender of patients were recorded. The results of the research were analyzed with chi-squared. Results: The prevalence of radix was found to be 0.74%, with entomolaris and paramolaris present in 54.54% and 45.46% of cases, respectively. There was no statistically significant difference between the two variables of radix type and gender, as indicated by a p-value of 0.08. The mean curvature and length of the radix root were measured to be 56.63° and 15.09 mm, respectively. The average root curvature in individuals diagnosed with radix entomolaris and paramolaris was found to be 62.33° and 49.80°, respectively. The study found that the root curvature of entomolaris exhibited a statistically significant difference compared to paramolaris (P=0.031). The mean length of the radix entomolaris and paramolaris roots was found to be 15.50 and 14.60 mm, respectively. There was no statistically significant difference observed in the mean root lengths of the various radix types (P=0.37). According to Vertucci's classification, all radixes were classified as type 1. Conclusion: The investigated population had a low incidence of radix. The curvature of radix entomolaris exhibited a statistically significant increase compared to radix paramolaris. There was no observed correlation between gender and the length of radix roots in relation to the type of radix root.