Spontaneous remission of internal root resorption during orthodontic treatment: A clinical follow-up report

Internal root resorption (IRR) is a pathologic process that occurs because of external stimuli that affect the pulp and result in the loss of dentinal tissue. The occurrence of IRR is considered relatively rare, and the etiology is not fully understood, although trauma is believed to be the main etiologic agent. The current study presented a case report of spontaneous remission of an IRR lesion diagnosed during orthodontic treatment. The lesion was characterized by a circular and delimited radiolucent image, located in the apical third of the root canal of the maxillary right lateral incisor diagnosed during orthodontic treatment. After the diagnosis, clinical and radiographic follow-up was performed without any intervention. The follow-up radiographic images showed loss of contour definition and reduction in the size of the lesion. At the end of orthodontic treatment, 27 months after diagnosis, the space of the lesion had been filled by tissue with similar radiopacity to the adjacent dentin, and the tooth did not change its color and response to mechanical and thermal stimuli. Eight years after the end of the treatment, the maxillary right lateral incisor still presented normal responses to vitality tests and color stability; therefore, it was impossible to notice the root canal space. The reported patient presents a possible behavior of the IRR characterized by spontaneous remission of the lesion. However, nonendodontic treatment after diagnosis should not be the routine therapy adopted for IRR because of the potential risk to the tooth. •Internal root resorption lesions are generally asymptomatic.•They are often detected during routine radiological examinations.•Early diagnosis allowed observation and spontaneous regression of the resorption.•The space gradually filled with less organized tissue.