Apical root resorption of maxillary fi rst molars related to headgear use as detected by cone beam computed tomography

Extraoral traction (EOT) by occipital headgear is a widely used anchorage and orthopedic approach for the control of maxillary growth. The aims of this study were: 1) to test the hypothesis that headgear use may increase the risk of apical root resorption, using cone beam computed tomography (CBCT) to detect root resorptions of maxillary fi rst molars, and 2) to assess which roots are more prone to resorption and to which extent. A total of 112 maxillary fi rst molars from 56 patients at 52 to 288 months after orthodontic treatment were evaluated to detect apical root resorption on CBCT images. Patients were divided into two groups: Group 1, patients who used EOT for up to six months; Group 2, patients who did not use EOT. The Levander and Malmgren scoring system was used to classify the root apices of maxillary fi rst molars. Signifi cance was set at 5%. Kappa statistics was used to assess agreement; scores were evaluated twice, according to the study methods. There were no differences in the frequency and severity of apical root resorption of maxillary fi rst permanent molars in the two groups as detected by CBCT. The use of EOT did not show association with frequency and severity of ARR considering a long time of follow up.