Assessment of apical root resorptions during orthodontic treatment with digital subtraction and geometric reconstruction

ObjectivesTo assess the severity of external apical root resorptions (EARR) in orthodontic patients by using digital subtraction and image reconstruction.Materials and methodsPeriapical radiographs from 34 individuals were obtained on the beginning (T0), after 6–7 months (T1), and after 12–13 months (T2) of treatment. These individuals had Angle Class I and II malocclusion and were treated with standard edgewise full fixed appliances (0.022 × 0.028-in.). The images were registered and subtracted on Regeemy® Image Registration and Mosaicking v.0.2.43-RCB (DPI-INPE, Sao Jose dos Campos, SP, Brazil). After reconstruction, root loss of the upper central incisors was measured on T1 and T2.ResultsThe difference between T1 and T2 was statistically significant for the left central incisor (P < 0.05). No statistically significant differences were found for the variables of the orthodontic treatment (extraction of first premolars, use of intermaxillary rubber bands, or type of malocclusion; P > 0.05).ConclusionsThe EARR was greater during the first 6–7 months of orthodontic treatment. Extraction of premolars, use of intermaxillary rubber bands, and type of malocclusion did not pose a significant influence to the EARR.