{Reference Type}: Journal Article {Title}: Comparative study of Vertucci and Ahmed classifications to evaluate the main root canal configuration of mandibular incisors in a Brazilian population. {Author}: Villa N;Weissheimer T;Vier-Pelisser FV;Alcalde MP;Vivan RR;Duarte MAH;da Rosa RA;Só MVR; {Journal}: Aust Endod J {Volume}: 48 {Issue}: 3 {Year}: Dec 2022 {Factor}: 1.719 {DOI}: 10.1111/aej.12576 {Abstract}: This study aimed to compare the main root canal configurations of mandibular incisors (MI) in a Brazilian population using Vertucci and Ahmed et al. classifications. One hundred and sixty-five human permanent MI were scanned using a micro-CT. Two examiners classified the samples according to Vertucci and Ahmed et al. classification. Kappa coefficient was employed. The majority of MI had a single root canal (52.1%). Type III Vertucci and 1 MI1-2-1 Ahmed et al. was the most common 2-canal MI (20%). In the apical third, the presence of one, two and three canals was found in 81.8%, 15.2% and 3% respectively. In the cervical and middle thirds, one, two and three canals were found in 86%, 12.2% and 1.8% respectively. Ahmed et al. classification was able to classify the entire sample studied, whereas 11 teeth (6.66%) did not fit Vertucci's classification.