Objectives: The aim of this investigation was to assess the currently available evidence concerning the complications and risk factors influencing the outcome of autotransplantation of teeth in humans.
Materials and methods: Electronic searches were conducted to identify randomized controlled and prospective clinical trials. Risk of bias within studies was assessed with the Downs and Black tool. Random-effects meta-analyses were conducted to pool the adverse event rates and relative risks with their 95% confidence intervals. Risk of bias across studies was assessed with the GRADE framework followed by sensitivity analyses.
Results: Thirty-eight studies were included in the analysis. Reported complications included the need for extraction, failure, hypermobility, pulp necrosis, pulp obliteration, and root resorption. Pooled complication event rates varied considerably, with small studies (<100 teeth) reporting greater complication rates. The analysis of risk factors was associated with both the primary outcome (extraction need) and secondary outcomes (failure, hypermobility, pulp necrosis, pulp obliteration, root resorption). The stage of root development seems to influence both the future survival, as well as the success of the transplanted teeth. Teeth with open apex were less likely to be extracted in comparison to teeth with closed apex (3 studies; 413 teeth; relative risk 0.3; 95% confidence interval 0.2-0.6).
Conclusions: Due to the small number of the contributing studies, their methodological limitations, and the heterogeneous results reported, no firm conclusions can be drawn.
Clinical relevance: Root development of the donor teeth has been established as one the most important factor related to the success of tooth autotransplantation.