| The purpose of this thesis is to understand the evolution of the epidemiologic pattern of four ear pathologies (i.e. congenital malformations-atresia of the external acoustic meatus; tumours-exostosis; otitis media, and otosclerosis) in Chilean Native populations, based on the possible correlation between palaeopathological findings and the observed prevalences these otologic pathologies have among contemporary Native Americans. Within this framework, the main objectives of this study are: (1) to evaluate the differences and similarities between the otopathologic patterns of prehistoric and historic Chilean Native populations, and establish possible causes of continuities or discontinuities between these models; (2) establish the possible causal agents of these pathologies and their eventual associated effects; to determine, if possible, the relative risk of these pathologies; and (3) to develop a palaeoepidemiological model of otologic pathologies for Chile's Native populations.; The populations examined consider prehistoric and historic groups from different latitudes and altitudes. Three pathologies (congenital disorders, tumours, and otosclerosis) are evaluated directly (i.e. macroscopically) and only otitis media is assessed indirectly (i.e. radiologically). Nonparametric tests are used to evaluate the degree of relationship between diseases and sex, altitude, and latitude.; The results of this study confirm the reported prevalence of tumours-exostosis in northern coastal populations but demonstrate their non-existence in southern coastal groups. The implications of this latter finding are discussed. The absence of otosclerotic cases corroborate what has been observed in other Native American groups. Congenital disorders although absent in our samples seem to have been present in prehistoric and historic times. The lack of findings in the groups studied is evaluated in relation to reported cases from neighboring populations. Traces of infectious middle ear disease (i.e. otitis media) are clearly demonstrated by means of radiology. Incidences of pneumatized temporal bones in coastal and highland populations suggest the existence of both intrinsic and extrensic factors in the high prevalence of otitis in ancient Native Chilean groups. Tentative explanations for these incidences are discussed. However, the lack of modern data hampers comparisons between past and present prevalences. |
