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.