Formative adaptations, diet, and oral health in the Azapa Valley of Northwest Chile

Indicators of oral health were recorded in a sample of 200 Formative period (1500 B. C.-A.D. 500) skeletons from archaeological sites located in the Lower Azapa Valley of northwest Chile. This period represents a major shift in subsistence strategies in the Atacama Desert, as coastal groups adopted agriculture and moved deeper into the valley. Frequencies of caries and antemortem tooth loss were compared between site locations (coast vs. valley) and by archaeological phase (early vs. late) to interpret the degree to which these incipient agriculturalists were reliant on domesticated resources. Overall, frequencies of caries (11.9 percent) and tooth loss (11.6 percent) are somewhat higher than for other prehistoric groups practicing a mixed subsistence strategy. However, residents of the interior valley exhibited significantly more dental decay and tooth loss than those along the coast. Our results identify that although the Formative period residents of the Lower Azapa Valley practiced a mixed subsistence strategy, the degree of reliance on agricultural production differed between the coast and the valley. We propose that these differential patterns in oral health are tied to local investment, adaptive cycles, and niche construction.