Occurrence of invasive cervical resorption after the completion of orthodontic treatment

The invasive cervical resorption (ICR) is an irreversible and progressive loss of tooth hard tissues involving coronal and root dentine that usually affects single permanent teeth. The aim of this study was to present the pattern of ICR lesions detected in three patients with no contributory medical and dental anamnesis, at different time periods after orthodontic tooth movements. Conventional radiographs and cone-beam computed tomography (CBCT) images were obtained by X-MindTM (Satelec), respective 3D Accuitomo (Morita). The present clinical study confirmed that orthodontic forces might be a key factor for generating an ICR and the risk of lesion occurrence is increased in long movements of the teeth because the orthodontic forces act continuously an extended time. However, it should not be overlooked the synergistic effect of additional factors such as traumatic injuries, periodontal inflammation, clenching, and grinding. The more advanced ICR lesions found in our study, described as Heithersay Class 3 and Class 4, appeared on conventional radiographs as irregular, diffuse, mottled radiolucencies extended both to the crown and deeply into the tooth root. CBCT proved to have a superior accuracy in detection and assessing the severity of ICR, since the conventional intraoral radiographs cannot afford an early and proper identification of the resorptive defect. Moreover, the CBCT image allows an accurate inspection of all surfaces of tooth due to the slices in sagittal, axial and coronal planes, and to avoid erroneous diagnostic conclusions. Currently, due to CBCT scan, the nature and extension of ICR lesion into the tooth structures can be exactly evaluated.