A well-defined coronal radiolucent area involving an impacted third molar.

The dentigerous cyst is the most common developmental odontogenic cyst and appears as an asymptomatic, well-defined radiolucent area surrounding the crown of an impacted tooth. Because of potential serious complications, lesions that are consistent radiographically with a dentigerous cyst should be totally removed and examined microscopically to establish a definitive diagnosis.