Infant growth, development and tooth emergence patterns: A longitudinal study from birth to 6 years of age.

OBJECTIVE: To test the association of child's growth/development status and socioeconomic variables with dental emergence patterns.

DESIGN: A sample of 359 children belonging to a birth cohort of over 5000 children born in 1993 in Pelotas (Brazil) was studied in 1998-1999. Previously trained observers collected birthweight, head circumference at birth, birth height, gestational age, smoking during pregnancy, child's sex and skin colour, height by age at 6 months of age, caries experience in the deciduous teeth, number of emerged teeth at 6 and 12 months of age and emergence stages of the first permanent molars at 6 years of age. Family income, parental educational attainment and anthropometric measurements were collected at children's homes. Poisson regression models were applied in order to select best predictors of pairs of emerged teeth at 6 and 12 months of age and emerged (yes/no) first permanent molars at 6 years of age.

RESULTS: Children shorter than 49cm had, on average, less pairs of emerged teeth at 6 months of age. Twelve-month-old children with birth height < or =49cm, presenting height-for-age deficit at 6 months of age and the females also presented less pairs of emerged teeth. Stunted children at 6 months of age were more likely to have non-emerged first upper left and lower right permanent molars at 6 years of age.

CONCLUSIONS: Important developmental and nutritional variables at birth and throughout the early life may predict the numbers of emerged teeth children have in their oral cavity.