Deciduous dental microwear of prehistoric juveniles from the lower Illinois River valley

Scanning electron microscopy was used to study age-related changes in the dental microwear of 36 prehistoric juveniles ranging from 6 to 27 months of age. Juveniles from horticultural (Middle Woodland) and agricultural (Mississippian) groups were studied to allow an investigation of the impact of diet on deciduous microwear. Inclusion of both molars and incisors in the sample permitted identification of age at earliest appearance of wear and comparisons between the age-related microwear characterizing different tooth types. Data on feature frequency and enamel surface characteristics were analyzed. Microwear feature frequencies generally increase with age and/or exposure to wear. Enamel surface characteristics show consistent qualitative changes associated with both age and exposure to wear. Molars and incisors differ for such surface characteristics in a way that make biomechanical sense, given the relative bite forces characterizing these teeth. Dietary reconstruction based on deciduous microwear is complex because of the effects of both age and exposure to wear on feature frequencies and enamel surface characteristics. Nonetheless, the present analyses suggest that 1) diets differed for younger and older juveniles within each cultural group and 2) the Middle Woodland juvenile diet was both harder and more varied in physical consistency than the Mississippian juvenile diet.