Can the severity of root resorption be accurately judged by means of radiographs? A case report with histology

Introduction: Root resorption of lateral incisors caused by the pressure of erupting canines is a well-known but relatively rare problem in orthodontics and general dentistry. It is usually diagnosed on radiographs. The purpose of this article is to discuss some difficulties associated with evaluating root resorption from radiographs alone. A case report is presented as an example. Methods: Radiographs showed that an 11-year-old girl had marked root resorption of the maxillary lateral incisors, caused by the impacted permanent canines. The incisors were to be extracted. Several months before the extractions, a canine had been surgically exposed to remove pressure from the incisor root. The lateral incisors were analyzed histologically, and the histologic findings were compared with those of the patient's mandibular first premolars, which had been extracted. Results: The resorption of the lateral incisors was more severe than expected from the radiographs. The resorption extended far into the pulp. Most, although not all, root resorption areas showed histologic evidence of repair, but the amount of repair was far from functional repair levels. The mandibular first premolars had no signs of resorption, thus excluding systemic causes. Conclusions: The severity of root resorption of lateral incisors cannot be accurately judged from radiographs alone.