title: Relationship of tooth wear to chronological age among indigenous Amazon populations.
abstract: In indigenous populations, age can be estimated based on family structure and physical examination. However, the accuracy of such methods is questionable. The aim of this cross-sectional study was to evaluate occlusal tooth wear related to estimated age in the remote indigenous populations of the Xingu River, Amazon. Two hundred and twenty three semi-isolated indigenous subjects with permanent dentition from the Arara (n = 117), Xicrin-Kayapó (n = 60) and Assurini (n = 46) villages were examined. The control group consisted of 40 non-indigenous individuals living in an urban area in the Amazon basin (Belem). A modified tooth wear index was applied and then associated with chronological age by linear regression analysis. A strong association was found between tooth wear and chronological age in the indigenous populations (p <0.001). Tooth wear measurements were able to explain 86% of the variation in the ages of the Arara sample, 70% of the Xicrin-Kaiapó sample and 65% of the Assurini sample. In the urban control sample, only 12% of ages could be determined by tooth wear. These findings suggest that tooth wear is a poor estimator of chronological age in the urban population; however, it has a strong association with age for the more remote indigenous populations. Consequently, these findings suggest that a simple tooth wear evaluation method, as described and applied in this study, can be used to provide a straightforward and efficient means to assist in age determination of newly contacted indigenous groups.
authors.affiliation: Dental School, Department of Orthodontics, Federal University of Pará-UFPA, Faculty of Dentistry, Belém, Brazil.
authors.forename: Elma Pinto
authors.initials: EP
authors.lastname: Vieira
authors.affiliation: Dental School, Department of Orthodontics, State University of Rio de Janeiro-UERJ, Rio de Janeiro, Brazil.
authors.forename: Mayara Silva
authors.initials: MS
authors.lastname: Barbosa
authors.affiliation: Department of Orthodontics, State University of Rio de Janeiro-UERJ, Rio de Janeiro, Brazil.
authors.forename: Cátia Cardoso Abdo
authors.initials: CC
authors.lastname: Quintão
authors.affiliation: Department of Orthodontics, Federal University of Pará-UFPA, Faculty of Dentistry, Belém, Brazil.
authors.forename: David
authors.initials: D
authors.lastname: Normando
mesh_terms: D000367:Age Factors; D001938:Brazil / Q000453:epidemiology / Q000208:ethnology; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male; D057085:Tooth Wear / Q000453:epidemiology*