Macroscopic dental enamel hypoplasia in deciduous teeth: health conditions and socio-economic status in nineteenth- to twentieth-century Granada, Spain

This study explores the relation between dental enamel hypoplasia and socio-economic status and health conditions in the nineteenth- to twentieth-century Granada, Spain. The Granada osteological collection of infants and young children was analyzed. Macroscopic enamel defects were examined and scored in 1791 deciduous teeth of 177 individuals aged between 6 months of gestation and 85 months postnatal. Detailed information on the last address where the children’s family lived, and the costs and type of coffin used in the burial, facilitated the estimation of the socio-economic status of the families. The prevalence of affected children was relatively high (19.8%) and there were no significant differences in the distribution of enamel defects between municipal districts of the city of Granada and the type of coffin. According to the age at onset of the physiological stressful events, 23.8% of children exhibited enamel hypoplasia during the prenatal period, 19.1% during the perinatal period, and 57.1% in the postnatal period. Analyzing the chronological distribution, two peaks of occurrence of stressful events were observed in the decades of the late 1930s and the mid-1940s, and in the early 1970s. The prevalence of enamel hypoplasia of the individuals analyzed does not seem to be associated with the socio-economic status of their families. However, the chronological distribution showed two peaks of high frequency related to different historical periods of economic and social crisis. The analysis of dental enamel hypoplasia provides an excellent index of developmental stress levels in the past.