Abstract
BACKGROUND: Traumatic dental injuries (TDIs) in early childhood exert a negative impact on the quality of life of children and their families. However, there is no evidence from cohort studies on which to base prevention strategies at the beginning of life, when children are entirely dependent upon supervision. The aim of the present study was to estimate the incidence of TDI in the first year of life and explore risk factors in a birth cohort followed up in three major cities in different regions of Brazil. METHODS: A birth cohort study was conducted with children in the cities of Porto Alegre, Salvador, and Manaus. Socioeconomic, demographic, and anthropometric characteristics were collected at baseline. Behavioral characteristics were collected when the children were six and 12 months of age. After the first year of life, clinical examinations were performed by trained, calibrated dentists for the assessment of TDI (Andreasen's criteria). Poisson regression models were used to estimate associations between the independent variables and TDI, with the calculation of crude and adjusted relative risk (RR) and respective 95% confidence intervals (CI). RESULTS: The incidence of TDI in the first year of life (range: 12 to 16 months) was 18.1% (95% CI: 13.6-22.6%). The multivariable analysis revealed a significantly greater risk of TDI in children from non-nuclear families (RR = 1.83; 95% CI: 1.11-3.00) as well as those whose mothers had a higher level of schooling (RR = 2.42; 95% CI: 1.04-5.63) and when tooth eruption began up to six months of age (RR = 2.30; 95% CI: 1.34-3.95). Being the first-born child was a protective factor (RR = 0.48; 95% CI: 0.27-0.87) for the occurrence of the outcome. CONCLUSION: The high incidence of TDI in the first year of life indicates the need for primary prevention strategies with an emphasis on active supervision in the first months of life. Risk factors associated with TDI related to the family, mother and child suggest pathways for the planning of such strategies.