Incidental findings on dental radiographs: dentigerous cyst.

Dentigerous cysts are the second-most-common cysts occurring in the jaws. A dentigerous cyst is formed as a result of fluid accumulation in the reduced enamel epithelium surrounding an unerupted tooth. These cysts typically present as well-defined pericoronal radiolucencies either superior or lateral to the unerupted tooth. Dentigerous cysts involving the posterior maxillary teeth tend to grow into and fill the maxillary sinus and, hence, are discovered late. Posterior mandibular dentigerous cysts commonly extend well into the ramus. There are often no clinical symptoms, with the exception of swelling once the cyst reaches a considerable size.