Dilated odontome in the mandibular third molar region.

The dilated odontome is the most severe form of the dens invaginatus (dens in dente), which is extremely rare in the mandible, especially in the molar region. A case is reported in a 28-year-old female with an unusual ringlike radiopaque appearance of the mandibular third right molar on panoramic x-ray. CT scan findings were suggestive that the intraosseous circular radiopaque formation was a dilated odontome. The alveotomy of the "tooth" was performed, and histopathological analysis of the inner and surrounding soft tissue revealed a diagnosis consistent with a dilated odontome.