To what extent are impacted canines associated with root resorption of the adjacent tooth?: A systematic review with meta-analysis.

BACKGROUND: The authors' aim in this systematic review was to evaluate to what extent impacted canines are associated with root resorption (RR) of the adjacent tooth by using cone-beam computed tomography. METHODS: The authors performed an open-ended electronic search of the Cochrane Library, Latin American and Caribbean Health Sciences Literature, PubMed (MEDLINE), Scopus, and Web of Science and a partial gray literature search by using Google Scholar, Open Grey, and ProQuest. The authors included studies in people (adolescents, adults, and older adult) with impacted maxillary permanent canines in which the investigators assessed the incidence of RR in adjacent teeth. The investigators detected RR by using cone-beam computed tomography. Two reviewers independently performed the study selection, data extraction, and risk of bias assessment with no language restrictions. The selection criteria included observational studies. RESULTS: From the 953 studies recorded in databases, the authors included 18 studies. The meta-analysis results revealed that the most frequent position of impacted canines was 56.99% palatal (95% confidence interval [CI], 47.032% to 66.673%); the apical one-third was the most prevalent one-third for RR (56.87%; 95% CI, 38.880% to 73.628%). The intensity of RR was slight (43.2%; 95% CI, 35.229% to 51.352%), although 30.9% (95% CI, 19.007% to 44.261%) of RR was severe. Although the studies had different sample sizes, the main methodological problem was the absence of a control group and follow-up. CONCLUSIONS: RR in maxillary incisors was correlated with their contact with maxillary canines during eruption. Delayed eruption or treatment of impacted canines may lead to resorption of the adjacent lateral and central incisors. All root levels and surfaces of teeth associated with impacted maxillary canines can be resorbed to different levels of severity, but the apical one-third with slight resorption is the most common. PRACTICAL IMPLICATIONS: Knowing to what extent impacted canines are associated with root resorption of the adjacent tooth before starting any intervention, and being able to share this information with the patient, caregivers, or caregivers and patient, allows the choice of the most appropriate treatment.