Acculturation and 4-year caries increment among children of foreign-born mothers in Sweden: a register-based cohort study

BACKGROUND: To study the association of maternal age upon arrival and length of residence in Sweden with the 4-year caries increment in their children between ages 3 and 7 years in relation to the human development index (HDI) of the maternal country of origin. METHOD: This registry-based cohort study included all children born in 2000–2003 who resided in Stockholm County, Sweden, at age 3 years and who were followed up at age 7 (n = 63,931). Negative binomial regressions were used to analyze different models adjusted for sociodemographic factors. RESULTS: Children of foreign-born mothers, regardless of the HDI of the maternal country of origin, had a higher risk of caries increment between ages 3 and 7 years than children of Swedish-born mothers. Furthermore, children of mothers who had arrived from a low or medium HDI country had a lower caries increment if their mothers arrived before age 7 compared with after age 7. Nearly half (44%) of the children whose mothers arrived in Sweden at age ≥ 20 years from a low HDI country had a caries increment compared to 22% of the children whose mothers had arrived in Sweden before 7 years of age. Furthermore, children whose mothers were born in a low HDI country and had resided in Sweden ≤ 19 years had approximately 1.5 times higher risk of caries increment compared to children of mothers who had resided in Sweden for more than 20 years. CONCLUSIONS: Caries increment in the children of foreign-born mothers was associated with the age of their mother when she arrived in Sweden and was lower when the mother had arrived before age 7 years. This indicates an intergenerational effect that carries over to the children and is greater the longer the mother has participated in Swedish dental healthcare.