Antecedents and correlates of hypoplastic enamel defects of primary incisors.

Four hundred and fifty-five exfoliated primary incisors were obtained from children whose mothers provided information about a wide range of pre-, peri-, and postnatal characteristics of both the mother and child. These teeth then were examined for the presence of hypoplastic enamel defects (HED). The basic form of the null hypothesis tested was that children who had HED of a primary incisor did not differ from those who did not have such a defect. Of the primary incisors examined, 18.5% had HED (25.0% maxillary and 10.1% mandibular). The following items were found to be associated most strongly (P less than 0.003) with an increase in a child's risk of developing HED; 1) maternal antenatal history of smoking, higher prepregnancy weight, and failure to obtain prenatal care during the first trimester; 2) prematurity, low birth-weight and their associated correlates; and 3) postnatal measles infection. Left-handedness, maternal tea and Tylenol (McNeil Consumer Products Co., Fort Washington, PA) consumption, and failure to screen for undue lead burden were associated less prominently (P less than 0.05) with HED prevalence. Season of birth and serum and dentin lead levels were not related to the prevalence of HED. Many of these risk factors are also covariates of low socioeconomic status such as suboptimal nutrition and increased risk of infection. Additional investigation is needed to delineate the associations between specific pre- and perinatal nutritional and infectious factors, socioeconomic status, and HED development.