A lateral periodontal cyst in association with a follicular cyst

A case is described in which two separate developmental odontogenic cysts were associated with an unerupted lower third molar tooth. Radiological and histological examination showed that these were a lateral periodontal cyst and a follicular (dentigerous) cyst. This unusual occurrence provides substantial evidence that the periodontal cyst may have an origin from the cell rests of Malassez.