Birth order - a risk factor for dental trauma?

Background Many character traits are influenced by birth order with greatest differences between first and lastborns. Aim To investigate the influence of birth order on the risk of dental trauma. Methods Five hundred mothers in Switzerland were interviewed personally regarding dental trauma in their children. Inclusion criteria were a family size of at least two children. Data of 1282 children were collected. Results Thirty‐two percent of the children had sustained one or more dental trauma before the age of 16 (57% male, 43% female). In children who had sustained dental trauma twice, the gender ratio moved to 68% male and 32% female (P = 0.003). Regarding birth order, lastborns sustained more second dental traumas. Relative risk of second dental trauma was 2.1 times higher in lastborns than in firstborns (P = 0.02). Moreover, certain character traits in children are influenced by birth order. According to their mothers, lastborns were more curious, less calm and less deliberate than firstborns (P