RESUMEN
AIM: To assess the prevalence of C-shaped canal systems in mandibular second molars, in samples of modern and pre-Hispanic Mayan individuals in Yucatán, Mexico, and to analyse the trait through time and attempt to find new evidence of ethnical bonds between populations. METHODOLOGY: Three hundred and forty-one randomly selected patients were treated in the Endodontic Clinic at the Dental school of the Universidad Autónoma de Yucatán, and 48 mandibular second molars from pre-Hispanic Mayan collections were macroscopically and radiographically inspected. Statistical analysis was performed with a Fisher's exact test to compare the prevalence of C-shaped canal systems in modern and archaeological samples. RESULTS: In the clinical observation, 118 of 341 (35%) patients treated endodontically had C-shaped mandibular second molars. In the radiographical evaluation, 17 of 48 (35%) archaeological molars had fused roots and pulp chamber morphology categorized as C-shaped. There were no significant differences between the frequencies in both samples. CONCLUSION: This study highlighted that a one-rooted mandibular molar was likely to have a C-shaped canal. The similarity between ancient and modern samples indicates that the genetic make-up since the European conquest has not affected the expression of this trait. This study supports the theory that the Mayan population has a relationship with the Northeast Asian population.