Evaluation of the Prevalence of Radix Entomolaris in First and Second Mandibular Molars in Yazd Population Using Cone-Beam Computed Tomography

The third root of mandibular molar teeth is the most important normal anatomical variation in these teeth. Failure to recognize the presence of this root is one of the most common reasons for treatment failure in these teeth. Therefore, the aim of this study was to investigate the prevalence of Radix Entomolaris in the mandibular first and second molars in the population of Yazd City using CBCT imaging.

In this study, 217 CBCT images prepared in an oral and maxillofacial radiology clinic were examined. The presence of the third root in the first and second molar teeth of the mandible was investigated according to the gender of the patients and the side of the tooth placement. Data were analyzed using SPSS16 software and Chi-Square statistical test. 

The prevalence of Radix Entomolaris in the present study in first molar and second molar teeth was recorded 5.1% and 1.8%, respectively. It was reported that its bilateral prevalence was 1.4%. In unilateral cases it was observed more on the right side. The occurrence of Radix Entomolaris had no statistically significant relationship with gender (P>0.05).

The overall frequency of Radix Entomolaris in the population of Yazd City is 6.9%. Its frequency is more likely to be unilateral, mostly in the first molar and without the influence of gender.