The present study aimed to evaluate the internal configuration of the maxillary molars of a population from the Northeast region of Brazil. Cone-beam computed tomography (CBCT) exams from 512 patients (1501 teeth) were evaluated regarding the anatomical configuration of the root canal system, according to Vertucci's classification. The images were obtained using a Prexion 3D scanner operating at 90 kVp and 4 mA. The voxel size was 0.125 mm and the cut thickness was 1 mm. The images were then analyzed in the Prexion 3D Viewer software. The data were analyzed statistically by Pearson's chi-square test, with 5% of significance. The first and second molars presented three roots in 99.14% and 87.27% of the cases, respectively. In relation to the number of canals, the first and second molars had a significantly higher frequency of three and four root canals respectively, presenting a higher prevalence of types I and II (p < 0.001). The second mesiobuccal canal (MB2) was observed in 48.21% and 22.72% of the first and second molars, respectively (p < 0.001). The identification of the MB2 canal was greater in young and adult patients (p < 0.001), presenting a higher prevalence in male patients (p < 0.001). The internal configuration of the MB root was influenced by gender and by age, presenting a higher prevalence of the MB2 in male patients younger than 50 years of age.