Spatial Variation of Dental Caries in Late Holocene Samples of Southern South America: a Geostatistical Study

Abstract

Objective: The spatial variation of dental caries in late Holocene Southern South American populationswill be analyzed using geostatistical methods. The existence of a continuous geographical pattern ofdental caries variation will be tested. Methods: The author recorded dental caries in 400 individuals andcollated this information with published caries data from 666 individuals. Then, a Caries Index (CI) wascalculated. The caries spatial distribution was evaluated by means of 2D maps and scatterplots.Geostatistical analyses were performed by calculating Moran´s I, correlograms and a Procrustes analysis.Results: There is a relatively strong latitudinal continuous gradient of dental caries variation, especiallyin the extremes of the distribution. Moreover, the association between dental caries and geography wasrelatively high (m12=0.6). Although Northern and Southern samples had the highest and lowestfrequencies of dental caries respectively, the central ones had the largest variation and, they had lowerrates of caries than expected. Conclusion: The large variation in frequencies of dental caries of thepopulations located in the center of the distribution could be explained by their subsistence strategies,characterized either by the consumption of wild cariogenic plants or cultigens obtained locally or byexchange, a reliance on fishing or the incorporation of plants rich in starch rather than carbohydrates. Itis suggested that dental caries must be considered a multifactorial disease, which results from theinteraction of cultural practices and environmental factors, and can change how we understandsubsistence strategies and how we interpret dental caries rates.