Concrescence: report of a rare case.

Concrescence represents an uncommon developmental anomaly in which juxtaposed teeth are united in the cementum but not in the dentin. The incidence of concrescent teeth is reported to be highest in the posterior maxilla. The presence of concrescent teeth may influence surgical procedures as well as periodontal, endodontic and even orthodontic diagnoses and treatment. Therefore, consideration should be given to the possible occurrence, recognition, and implications of this anomaly in diagnosis and treatment planning. The purpose of this article is to report a case of concrescence between an impacted third molar and an erupted second molar that was identified postextraction.