# Prevalence of Middle Mesial Canal in Mandibular First Permanent Molars in a Persian Population: An In Vivo Cone‐Beam Computed Tomography Study

## TL;DR

This study found that only 8.7% of Persian mandibular first molars have a middle mesial canal, with no gender or age differences but a link to an additional distal canal.

## Contribution

The study provides new prevalence data for the middle mesial canal in a Persian population using CBCT imaging.

## Key findings

- The prevalence of the middle mesial canal in mandibular first molars was 8.7%.
- There was no significant difference in canal prevalence between genders or age groups.
- The presence of a middle mesial canal was significantly associated with an additional distal canal.

## Abstract

This study aimed to identify the prevalence of the middle mesial canal (MMC) in mandibular first permanent molars in a Persian subpopulation sample using cone‐beam computed tomography (CBCT). The secondary aim was to correlate the incidence of MMC with variables such as gender, age, and the presence of an additional distal canal.

A total of 390 mandibular first molars from 314 CBCT images were retrospectively evaluated. The presence of the MMC was recorded while considering related factors such as additional distal canal and demographic information of the patients (age and gender). Fisher's exact tests and independent‐samples t‐test were used for the statistical comparisons with a significance level of 0.05.

Among 390 mandibular first molars, 34 teeth contained an MMC (8.7%). The number of teeth with the MMC in women was equal to that of men. There was no significant difference between the two genders in the prevalence of the MMC (p > 0.05). The prevalence of patients' MMC had no significant relationship with their age (p > 0.05). However, there was a significant association between the presence of the MMC and an additional distal canal (p < 0.05).

The incidence of an additional distal canal in teeth with a diagnosed MMC was statistically significant. The prevalence of the MMC in mandibular first molars in the study population was low; however, accurate knowledge of root canal morphology in terms of the presence of an additional root canal in these teeth should be considered.