Traumatic Dental Injuries in the Primary Lower Incisors.

BACKGROUND: Primary lower incisors can also suffer traumatic dental injury (TDI), which may lead to consequences for both primary and permanent dentitions.

AIM: To evaluate the prevalence of traumatic dental injuries (TDI) in the primary lower incisors and the factors associated with their occurrence and with the incidence of sequelae in the successor permanent teeth.

DESIGN: 2926 dental files from patients who attended a reference center for dental trauma in the primary teeth, from 1998 to 2020, were screened. Multilevel Poisson regression analyses were conducted between exploratory variables related to the traumatized teeth and outcome variables: occurrences of severe TDI and sequelae in the permanent successor. Prevalence ratios (PRs), Relative risks (RRs), and respective 95% confidence intervals (95% CIs) were calculated.

RESULTS: 113 (3.9%) children and 208 teeth presented TDI in the primary lower incisors. Children aged >4 years at the time of TDI had lower prevalence of severe TDI (PR=0.43; 95%CI = 0.19-0.94) than children aged up to 2 years of age. Moreover, severe TDI was significantly associated with the occurrence of sequelae in the permanent successors (RR=3.97; 95%CI = 1.72-9.18), when compared to not severe TDI.

CONCLUSIONS: The prevalence of TDI in the primary lower incisors is low, being more prevalent in early-aged children. Older children also present less frequent severe TDI, and the risk of sequelae in permanent teeth is higher when resulting from severe TDI.