title: Facial biometry of Amazon indigenous people of the Xingu River - Perspectives on genetic and environmental contributions to variation in human facial morphology.
abstract: OBJECTIVE
  To evaluate facial morphology of non-mixed indigenous people living in the Xingu region. Studies on these populations report that the total genetic diversity is as high as that observed for other continental populations. On the other hand, eating habits are different between indigenous and urban population, as indigenous people still have traditional habits.
  
  
  METHODS
  The sample consisted of 106 indigenous subjects, in permanent dentition stage, belonging to four groups: Arara-Laranjal (n = 35), Arara-Iriri (n = 20), Xikrin-Kaiapó (n = 24), and Assurini (n = 27).
  
  
  METHODS
  Standardized facial photographs were obtained, and fourteen measurements were analyzed. Intra- and intergroup homogeneities were examined by discriminant analysis, followed by anova and Kruskal-Wallis tests. Sexual dimorphism to each village was analyzed by Student's t-test or Mann-Whitney test, at p < 0.05.
  
  
  RESULTS
  Significant facial differences were found between male and female, indicating that sex data should not be grouped for intergroup comparison. Discriminant analysis showed a large intergroup heterogeneity, while an intragroup homogeneity was found, especially for females. It was also observed that some morphological features of the face are specific to some villages, regardless of ethnicity.
  
  
  CONCLUSIONS
  Facial morphological characteristics were strongly different among groups, even comparing villages from the same ethnicity. Furthermore, a low diversity within groups was observed. Our findings, supported by previous reports on genetics and eating habits in these populations, reinforce the role of the genetic determination on craniofacial morphology.
authors.affiliation: Federal University of Pará, Belém, PA, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Barbosa
authors.affiliation: Federal University of Pará, Belém, PA, Brazil.
authors.forename: E P
authors.initials: EP
authors.lastname: Vieira
authors.affiliation: Federal University of Pará, Belém, PA, Brazil.
authors.forename: C C A
authors.initials: CC
authors.lastname: Quintão
authors.affiliation: Federal University of Pará, Belém, PA, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Normando
mesh_terms: D000328:Adult; D001699:Biometry; D001938:Brazil / Q000208:ethnology; D002508:Cephalometry; D005006:Ethnicity / Q000235:genetics; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007199:Indians, South American / Q000208:ethnology* / Q000235:genetics; D008297:Male; D012727:Sex Characteristics; D012737:Sex Factors
keywords: biometry; face; genetics; indigenous population