Cone Beam Computed Tomography (CBCT) Aid in the Management of Apical Root Resorption of Impacted Maxillary Canines and Physiologically Erupted Maxillary Canines after Orthodontic Treatment

The aim of this study is to evaluate the effects of orthodontic traction, by means of light and controlled forces, on root length in impacted maxillary canines and physiologically erupted maxillary canines. Disinclusion of impacted maxillary canines is a frequent procedure in orthodontics due to their higher incidence of impaction. The effects of orthodontic traction, by means of light and controlled forces, can lead to a resorption of the root length in impacted and physiologically erupted teeth. Therefore, apical root resorption is a common phenomenon that must be taken into consideration. Apical root resorption measurements were taken using pre-treatment CBCTs and pre-treatment and post-treatment digital panoramic radiographs of 52 patients who underwent fixed-appliance treatment by using light and controlled orthodontic forces. The experimental group consisted of 26 patients with one impacted maxillary canine. The control group consisted of 26 patients without any impaction. Apical root resorption was calculated from root lengths before and after orthodontic treatment. In the experimental group, impacted canines with incomplete apical formation underwent root elongation, while impacted canines with completed root formation went through apical root resorption. The latter showed a slightly greater apical root resorption (0.2 mm) compared to the control group (95% confidence interval; p = 0.04). The extent of root resorption of impacted canines was significantly higher than that of physiologically erupted ones. However, this differential resorption did not compromise the structural and functional integrity of the involved teeth. The orthodontic treatment performed with light and controlled forces is, therefore, a procedure to be considered acceptable and safe.