Radicular Cyst Associated with Type 3B Dens Invaginatus in a Permanent Maxillary Lateral Incisor.

Dens invaginatus (DI) is a developmental abnormality of the tooth resulting in the invagination of the enamel organ into the dental papilla before the calcification of dental tissues. DI is one of the common dental deformities, but its association with the radicular cyst (RC) is still very uncommon. Oehler's Type 3B DI has a deep invagination that extends apically communicating with the apical area. This allows the entry of irritants predisposing for dental caries, periapical lesions, and pulp pathology if there is a communication with pulp. The sequelae of undiagnosed and untreated coronal invaginations include abscess formation, retention of neighboring teeth, displacement of teeth, cysts, and internal resorption. Identifying this anomaly early will prevent further complications. This presentation describes a case of RC associated with Type 3B DI in a permanent maxillary lateral incisor in a 9-year-old girl. A brief review of both pathologies is also discussed.