Association of infant growth with emergence of permanent dentition among 12 year-aged southern Chinese school children

BACKGROUND: There is a need to comprehensively investigate the relationship between tooth eruption and infant growth to explain the theory of tooth emergence. This study aimed to investigate the association between infant growth during the first year of life and the emergence of the permanent teeth. METHODS: A random sample of 668, 12-year-old students was recruited from a birth cohort. Erupted permanent tooth number was recorded. The association of infant growth (growth trajectories and growth rates) and permanent tooth emergence was examined through logistic regression analyses. The regression model was adjusted by potential confounders including gender, gestational age, mode of delivery, type of feeding, parental education, and health status. RESULTS: The response rate was 76.9% (n = 514). Two hundred and forty-five (47.7%) children had all 28 permanent teeth erupted. Infants who had higher birth weight z-scores and those who had grown slowly during the first three months of life were more likely to have complete permanent teeth emergence at their 12-year-old in both unadjusted (p < 0.01) and adjusted model (adjusted for gender, gestational age, mode of delivery, type of feeding, parental education, and health status, p < 0.01). However, no significant association was found between the growth trajectories and permanent tooth emergence in either unadjusted or adjusted models (p > 0.05). CONCLUSION: Birth weight and infant growth during the first three months of life might be associated with permanent tooth emergence at their 12 years of age. This association may be applied in the assessment of risk for dental caries or malocclusion.