Dental Reduction and Diet in the Prehistoric Ohio River Valley

Post-Pleistocene dental reduction has been documented around the globe. Dietary change is a common factor in many of the selectionist models explaining this reduction. The current study examines tooth size in the prehistoric Ohio River Valley of Indiana and Kentucky to determine if a dental reduction occurred from the Late Archaic to the Mississippian periods and, if so, to see if dietary shifts are associated with dental reduction. Data from 282 individuals are compiled from 21 sites that span from 5000 BC to AD 1400. These sites represent Late Archaic foragers, Early/Middle Woodland early horticulturalists, Late Woodland mixed-economy horticulturalists, and Mississippian agriculturalists. Previous studies have indicated that the diet became less abrasive through time in this region but became harder from the Late Archaic to the Early/Middle Woodland just to became softer again thereafter. Buccolingual diameters were taken for all suitable permanent teeth. Standard descriptive statistics, ANOVA, percent differences, and rate of change were calculated for each dental measurement to determine the degree of change between the various temporal groups. It was found that a dental reduction occurred in the Ohio River Valley that was more pronounced in females and in the maxillary molars. The general reduction in tooth size mirrors the reduction in dietary abrasiveness. By contrast, it does not seem to follow the course of dietary hardness.