Long-term evaluation of apical root resorption after orthodontic treatment using periapical radiography and cone beam computed tomography.

OBJECTIVE To evaluate the frequency of Apical Root Resorption (ARR) after orthodontic treatment at 52-288 months using periapical radiography (PR) and cone beam computed tomography (CBCT). METHODS Radiographic images obtained from 58 patients, before (T1) and after orthodontic treatment (T2), and following 52-288 months of treatment were analyzed by three members of the Brazilian Board of Orthodontics. Apical structures were evaluated by PR images (T2 and T3), using Levander and Malmgren scores. The presence of ARR on CBCT images was detected only at T3. The Kolmogorov-Smirnov test was used for statistical analyses, and the level of significance was set at 5%. Kappa statistics determined interobserver agreement. RESULTS The more frequent ARR were with scores 1 in T2 (51.6%) and T3 (53.1%), when evaluated by PR (p > 0.05). When compared the frequencies of ARR in T3 among PR and CBCT images, the differences were significant for maxillary and mandibular premolar groups, and for mandibular molar group (p > 0.05). The teeth with highest frequency of ARR presence using CBCT images were maxillary lateral incisors (94.5%) and mandibular central incisors (87.7%), while the premolars showed the lowest frequency. The CBCT images showed that the teeth involved in orthodontic treatment with extraction present higher ARR frequency (p < 0.05). CONCLUSIONS PR showed more frequency of ARR in posterior teeth groups when compared with CBCT images. ARR did not change in long-term post treatment.