Clinical manifestations of tooth eruption in the first year of life and related risk factors in three regions of Brazil: multicenter birth cohort study

Purpose: Estimate the incidence of teething symptoms and investigate risk factors at three centers in different regions of Brazil. Methods: A prospective cohort study enrolled children at birth in the cities of Manaus (northern region), Porto Alegre (southern region) and Salvador (northeast region). Sociodemographic and anthropometric variables were collected at baseline and 6 months. At 12 months, data were collected on the child's health through structured interviews and dental examinations, including the primary outcome: occurrence of signs and symptoms of tooth eruption reported by parents. Statistical analysis involved Poisson regression with robust variance, with calculation of relative risks (RR). Results: The incidence of teething symptoms was 82.4% (238/289). The multivariate analysis revealed a higher occurrence of the outcome in the city of Salvador (RR = 1.39; 95% CI 1.23-1.58), when mother's education was more than 11 years (RR = 1.31; 95% CI 1.04-1.65), when a larger number of individuals resided in the home (RR = 1.15; 95% CI 1.02-1.29), when a smoker resided in the home (RR = 1.16; 95% CI 1.03-1.31) and when the child presented flu or cold in the first year of life (RR = 1.23; 95% CI 1.09-1.38). The most reported symptoms were fever (50.5%), irritability (42.6%), itching (40.8%) and diarrhea (35.3%). Most parents (82%) took some action to alleviate symptoms, including unprescribed systemic medication, such as analgesic, anti-inflammatory and anti-diarrheic agents. Conclusion: Reports of teething symptoms were associated with the city investigated, socioeconomic factors of the families and characteristics of the child's health. A high rate of administering unprescribed medication was also found.