Social and biological early life influences on severity of dental caries in children aged 6 years

Objective: To investigate the relationship between social and biological conditions experienced in very early life and dental caries in children aged 6 years. Methosd: The design was a dental caries cross-sectional study nested in a birth cohort study started in Pelotas, Brazil, in 1993. The cross-sectional study was carried out in 1999. A random sample of 400 6-year-old children was selected from among 5249 live births in 1993. The World Health Organization (1997) criteria were used to diagnose dental caries. Results from the oral health study were linked to the data concerning perinatal and childhood health and illnesses and family social conditions collected at birth, 1, 3, 6 and 12 months, and in the sixth year of life. Dental caries was the outcome measured at two levels of severity (very low: dmft less than or equal to 1; high: dmft greater than or equal to 4). Unconditional univariate and multiple logistic regression analysis were performed. Results: Self-employed and employees/unemployed, fathers with <8 years of education at time child was born, child's height deficit for age at 12 months; child who did not attend day care centre in sixth year of life; brushing teeth less than once a day, and children with sweet consumption of at least once a day at 6 years were risk factors for high dental caries after controlling for possible confounders. Conclusions: Harmful social and biological risk factors accumulated in early life contributed to the development of a high level of dental caries in childhood.