The incidence and severity of root resorption following orthodontic treatment using clear aligners

Abstract

Introduction: The aim of this study was to assess the incidence and severity of root resorption in patients who were orthodontically treated by clear aligner therapy. Methods: Linear tooth lengths of maxillary and mandibular teeth from the second molar to second molar were measured from pre-and post-treatment cone beam computed tomography examinations of 25 patients who were treated by a clear aligner system. Results: Mean reductions in tooth length varied according to tooth type, with maxillary central and lateral incisors experiencing the most resorption, of 0.5 ± 0.41 mm and 0.4 ± 0.56 mm respectively. All tooth types had most resorption fall within the <0.25 mm range, with 7% of central and lateral incisors accounting for resorption >1.5 mm. Although the level of resorption identified in this study was less than that reported for fixed appliances, overall, the trends were similar. Conclusions: Orthodontic treatment carried out with clear aligners resulted in root resorption that was largely clinically insignificant. There was a general trend towards more resorption affecting anterior teeth in both the maxilla and mandible. Original tooth length was found to be a predictor of the amount of resorption.