Clinical Outcome of Replanted Avulsed Anterior Teeth: A Retrospective Cohort Study

Long-term outcomes after replantation of avulsed anterior teeth remain difficult to predict. This retrospective study evaluated post-replantation tooth survival and assessed the tooth- and patient-level factors associated with tooth loss and ankylosis.

Patients with replanted avulsed anterior teeth treated between 2008 and 2021 were identified from a clinical database. Observation time extended from replantation to tooth failure or last follow-up. Kaplan-Meier analysis was used to estimate the survival probabilities using patient-cluster bootstrap confidence intervals (CIs). Cox and logistic regression models with patient-cluster robust standard errors evaluated the factors associated with tooth loss and ankylosis, respectively.

The cohort included 248 replanted anterior teeth from 180 patients; 19 teeth (7.7%) were lost and 103 teeth (41.5%) had ankylosis. The estimated 1- and 5-year survival probabilities were 96.8% (95% CI, 94.1%-98.8%) and 92.9% (95% CI, 87.7%-97.2%), respectively. In Cox regression analysis, no clinical variables were significantly associated with tooth loss after patient-cluster robust inference. Mandibular location (odds ratio, 0.41; 95% CI, 0.17-0.97) and alveolar bone fracture (odds ratio, 0.45; 95% CI, 0.22-0.89) were associated with lower univariable odds of ankylosis, but neither remained significant in the multivariable model.

Tooth retention and ankylosis should be interpreted as distinct outcomes after replantation of avulsed anterior teeth. Tooth loss was uncommon, but ankylosis was frequent, and independent prognostic factors for failure were not confirmed after accounting for sparse events and patient-level clustering.