Clinical and molecular factors associated with external apical root resorption by orthodontics: Umbrella review

The objective of this study was to analyze the available evidence on external apical root resorption (EARR) due to orthodontic movement to identify clinical and molecular factors associated with this condition. An umbrella review that included systematic reviews and meta-analysis was performed. Four databases were used (PubMed, Science Direct, Scopus, and Cochrane), and critical evaluation following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and admeasurement tool to assess systematic reviews (AMSTAR-2) guidelines were carried out. The study protocol was registered in PROSPERO (International prospective register of systematic reviews, CRD42020198971). One hundred and twenty-four papers were eligible for this investigation. After exclusion by title and abstract, 10 papers (four systematic reviews and six meta-analyses) were included in the study. Guideline AMSTAR-2 was applied, and evaluation was performed using the PRISMA guideline. Factors such as female gender, adulthood, conventional fixed orthodontic treatment, heavy, continuous, and prolonged loads, intrusive movements, and anterior superior teeth with abnormal roots increase the risk of developing this condition. At the molecular level, some biomarkers, such as interleukins (IL) I-1B, I-6, I-4, and dentin phosphoprotein, are significant to reach an early diagnosis of external root resorption (ERR), especially the gene of polymorphism IL-1B (+3954), which is the most important predictor of this condition in patients under orthodontic treatment. Clinical and molecular factors respond to individual characteristics that must be identified to define the risk of developing EARR. Cone-beam computed tomography is the most accurate tool to evaluate the dimension of this condition. Prolonged treatments must be avoided, and immunoassays to analyze proteins in the gingival crevicular fluid should be included to reach an early diagnosis.