Impacted Maxillary Canines Increase External Root Resorption Of Adjacent Incisors: Physical Proximity A Predisposing Factor

Background: The maxillary canines are of great importance both aesthetically and functionally. Ectopic eruption of maxillary canines cause various complications among which root resorption of adjacent incisors is most common. Objective: The objectives of this study were to investigate the prevalence, extent of resorption, and predisposing risk factors for incisor root resorption associated with impacted maxillary canines. Methods: Unilaterally and bilaterally impacted canines (n=53) from 42 patients (27 female, 15 male) who visited Department of Orthodontics for treatment were evaluated. CBCT scans were taken with NewTom GiANO NNT Scanner keeping in mind the risks associated with ectopic eruption of maxillary canines and were analyzed with 3D visualization software. Results: Among the studied impactions, 79.2% were impacted palatally and 11.3% buccally. The lateral incisors were the teeth most affected by resorption. 18 incisors were resorbed, which included 16 lateral incisors (30.2 per cent) and 2 central incisors (3.8 per cent). Among lateral incisors, the resorption was slight in 11 cases (20.8 per cent), moderate in 3 cases (5.6 per cent), and severe in 2 cases (3.8 per cent) while among central incisors, the resorption was only slight in 2 cases (3.8 per cent). A correlation was found between the proximity/contact of the impacted canine to the incisors and their resorption. Follicle size did not play a major role in incisor resorption. Conclusion: Canine impaction poses a higher risk for root resorption of adjacent incisors. Physical proximity (<0.5 mm) between impacted canine and adjacent roots of incisors is the most important predictor for root resorption. The width and the shape of the dental follicle of the impacted canines do not correlate with root resorption of maxillary incisors.