Application of different dental indicators of disruption to assess 'stress' in three prehistoric samples from northeast Iberian Peninsula

Abstract

Stress or disruption indicators observed in teeth have well-determined periods of formation, and hence, are especially useful on determining the presence of adverse conditions during childhood. The third millennium BCE in the northern Iberian Peninsula had deep changes in cultural and subsistence patterns, including less diversified diet patterns and higher population density, which has been related to increased disruptive events in human groups. Here, we compared different disruption indicators in teeth of a minimum of 164 individuals from three prehistoric samples from the northeastern of the peninsula: Cova del Pantà de Foix, Bòbila Madurell and Camí de Can Grau. The collection from Cova del Panta de Foix has previously been reported as having high ratios of disruption indicators. We have analysed the presence of LEH defects and fluctuating asymmetry of dental non-metric traits and compared the results obtained by these two different approaches. Our results showed that at the population level these two traits showed no relationship. Specifically, the Cova del Pantà de Foix sample showed the highest ratio of enamel disruption: 37.5% of teeth and 65% of individuals being affected. In contrast, 80% of the analysed traits in Bòbila Madurell were asymmetric, and 60% of these could be determined as fluctuating asymmetry. Additionally, lower second premolars exhibited asymmetry in the highest number of individuals. Altogether, these results suggest that acute disrupting events were common among all populations, but that the individuals from Cova del Pantà de Foix were more exposed to chronic disruption at least during the period of tooth mineralisation. These two indicators, are determined at different points in dental development. Therefore, the observed differences may have been related to the time at which the disruption occurred in childhood in each population, rather than children from one population being affected by more disrupting factors.