Enamel Hypoplasia and Childhood Stress in Prehistory: New Data from India and Southwest Asia

Abstract

Deficient formation of enamel during the development of deciduous teeth results in defects known as enamel hypoplasia. Prior analysis of the prevalence of deciduous enamel hypoplasias (DEH) at the prehistoric site of Inamgaon (1400–700bc, western Maharashtra, India) revealed an association between increasing aridity, semi-nomadic subsistence, and a decrease in prevalence of deciduous enamel defects (Lukacs & Walimbe, 1998, 2000 a). Many questions regarding the prevalence of deciduous enamel hypoplasia in prehistory remain unanswered: Is the presence of Localized Hypoplasia of Primary Canine (LHPC) teeth unique to Inamgaon? Or is this developmental defect typically found in other Jorwe culture sites? If so, how variable is the prevalence of DEH in human skeletal remains from Jorwe Culture archaeological sites? And, what are the implications of variation in LHPC prevalence for understanding childhood health and nutrition in prehistory?The Jorwe Culture comprises a distinctive and widespread group of early farming settlements on the Deccan Plateau of western India. Due to the practice of burying sub-adults in urns, infants and children comprise an unusually large percentage of the human skeletal and dental remains from Jorwe Culture sites. This report presents new data on LHPC prevalence for four sites in India: two large village settlements—Daimabad and Nevasa, and two small satellite farmsteads—Kaothe and Walki. For comparison we include a new data set for the urban centre of Kish in Southwest Asia. All teeth were visually inspected for enamel defects under oblique incandescent light with the aid of a 10 power hand lens. Enamel defects were classified according to recommendations of the Fédération Dentaire International/Dental Defects of Enamel standards (Clarkson, 1989; Fédération Dentaire International, 1982).Tooth count prevalence values for LHPC at Early Jorwe sites and at Kish confirm typical characteristics of defect expression: antimeres display small and non-significant differences, while isomeres exhibit large and statistically significant differences, with mandibular canines more frequently affected than maxillary canines. Among Early Jorwe sites total tooth count prevalences of LHPC range from 22·2% to 42·2%, and individual count prevalences range from 33·3% to 47·4%. These values have parallels among moderately to severely stressed modern humans that are characterized as disadvantaged in regard to their nutritional and health status. We infer that prehistoric people associated with the Jorwe expression of Chalcolithic culture lived in an environment that was sufficiently detrimental to growth and development that disruptions to enamel formation occurred.