RESUMO
This study examines levels of fluctuating asymmetry (FA) in Mexican residents, U.S. residents, and undocumented border crossers (UBCs) from Mexico to the United States. Craniofacial structures develop symmetrically under ideal circumstances; however, during periods of developmental stress random deviations from perfect symmetry, or FA, can occur. It is hypothesized that the UBC sample would represent individuals of a lower socioeconomic status (SES) who experienced higher stress levels during development, and that these individuals would consequently have higher levels of FA. Three-dimensional cranial landmarks were collected from 509 individuals representing the three resident groups. Geometric morphometric methods were used to calculate an FA score for each individual. The FA score provides a distance measure that is a scalar measure of the magnitude of FA in each individual. The results show that the difference in the means of the FA scores between UBCs and U.S. residents is 0.43 (pâ¯=â¯0.02), with UBCs showing significantly higher levels of FA compared to U.S. residents. Moreover, Mexican residents' FA levels are intermediate between and not significantly different from the other two samples. These results suggest that levels of FA may prove useful for reconstructing individuals' social and economic circumstances, and that craniofacial asymmetry provides a suitable biological marker for analyzing differences in SES among different groups.
Assuntos
Emigrantes e Imigrantes/estatística & dados numéricos , Assimetria Facial/etnologia , Americanos Mexicanos/estatística & dados numéricos , Crânio/anatomia & histologia , Adulto , Idoso , Biomarcadores , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Imigrantes Indocumentados/estatística & dados numéricos , Estados Unidos/epidemiologiaRESUMO
Entre los pueblos del México prehispánico, la costumbre de modificar la cabeza de los recién nacidos estuvo muy arraigada y difundida. Estas modificaciones producidas por planos compresores desalineados ocasionaron una deformación cultural asimétrica semejante a la que presentan los pacientes con plagiocefalia, con cambios estructurales en las órbitas, los cuales condicionan cuadros estrabológicos bien establecidos. Se estudiaron 18 cráneos del área maya, todos ellos adultos (10 hombre y 8 mujeres) a los cuales se les realizaron medidas directas e indirectas (rayos X y craneogramas). Como resultados del presente estudio podemos sospechar que las deformaciones culturales asimétricas del cráneo causaron una deformación semejante a la plagiocefalia con cambios en las órbitas que condicionan una distopia vertical importante y como consecuencia de la misma, un cuadro estrabológico de hipertropia en bloque