Unusual Location of Dens Invaginatus Causing a Difficult-to-Diagnose Pulpal Involvement.

This article reports on an unusual case of dens invaginatus in a maxillary third molar that was causing severe symptoms of irreversible pulpitis. This malformation was not clinically or radiographically identified, and the occurrence of referred pain made the early identification of the responsible tooth difficult. Determination of the tooth that was the source of symptoms was only possible after an observation period and fast aggravation of the pathologic process to cause pulp necrosis and extreme tenderness to percussion. The diagnosis of dens invaginatus was made only after extraction and sectioning. Histopathologic and histobacteriologic features of this case are illustrated.