P124 Atopic dermatitis in infancy and early childhood is not associated with adolescent dental hypomineralization

Abstract Evidence has been previously reported demonstrating an increased risk of primary dentition caries and molar incisor hypomineralization (MIH) in children with atopic dermatitis (AD). We aimed to examine the association between infantile and early-childhood AD and secondary dentition MIH in adolescence, which would point towards possible shared mechanisms of skin barrier and tooth enamel development. The study analysed data from 1920 mother–child pairs from a UK longitudinal cohort following mothers and offspring from preconception, through pregnancy, infancy, childhood and beyond. The UK Working Party diagnostic criteria were used to assess the presence of AD through standardized questionnaires and physical examinations by trained nurses. Children with AD at 6 months, 12 months or 6 years, or documentation of no AD at all three timepoints, were included. MIH was diagnosed in children aged 11–13 years based on dental photographs taken by trained nurses and reviewed by dentists. MIH was defined as hypomineralization of first permanent molars and permanent incisors based on international criteria. We excluded neonatal deaths and those with congenital anomalies, preterm births of < 37 weeks’ gestation and missing data. Confounding variables were identified using a directed acyclic graph; these were maternal age at child’s birth, prepregnancy body mass index, maternal education, parity, smoking during pregnancy, serum 25-hydroxyvitamin D, infant sex, gestational age, birth weight and breastfeeding duration. Logistic regression analyses related AD at each timepoint (6 months, 12 months and 6 years) and at all three timepoints to MIH at age 11–13 years. The prevalences of AD were 11.4% (48 of 422) at 6 months, 11.8% (50 of 422) at 12 months and 15.4% (65 of 421) at 6 years. Maternal and infant characteristics of infants with and without AD were similar. AD at each of 6 months, 12 months and 6 years was not associated with MIH at 11–13 years. The prevalences of MIH in those with and without AD at any age were similar (14.6% and 14.7%, respectively), with few changes after adjusting for potential confounding variables (adjusted odds ratio 1.20, 95% confidence interval 0.56–2.56; P = 0.64). In conclusion, analyses show that having AD in infancy or childhood is not associated with an increased likelihood of developing MIH affecting the secondary dentition in adolescence. This points away from shared mechanisms of skin barrier and tooth enamel development.