The C-shaped canal molar: an Endodontic-Archaeological study of the relationships between Mayan pre-Hispanic and contemporary population of Yucatán.

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.

Linear enamel hypoplasia at Xcambó, Yucatán, during the Maya Classic period: An evaluation of coastal marshland impact on ancient human populations.

Non-specific stress markers such as linear enamel hypoplasia (LEH) have been associated in the literature with a large number of possible conditions disrupting the individual's homeostasis, though metabolic strain originating synergistically by disease and malnutrition has been held to be the main cause behind enamel disruption. The analysis of LEH in the Maya Classic period site of Xcambó, located along the northern coast of the Yucatán peninsula, reveals high exposure to stressful conditions during infancy regardless of age and sex. Yet, the inhabitants of the site were of a medium to high social and economic status, with access to balanced and protein-rich nutritional resources, which should have functioned as a cultural buffer to the impact of stress. In the light of this apparent contradiction, this paper discusses the impact of environmental conditions on the record of metabolic stress. Our conclusions pose a cautionary caveat for inferring nutrition and status in ancient pre-antibiotic populations solely from the occurrence of linear enamel hypoplasia.