Periapical cyst

The periapical cyst (also termed radicular cyst, and to a lesser extent dental cyst) is the most common cyst of the jaw. It is caused by pulpal necrosis secondary to dental caries or trauma. The cyst lining is derived from the cell rests of Malassez. Usually, the periapical cyst is asymptomatic, but a secondary infection can cause pain. On radiographs, it appears a radiolucency (dark area) around the apex of a tooth's root.