[Lateral periodontal cysts]

The lateral periodontal cyst is a rather infrequently reported odontogenic cyst. The cyst seems to develop in direct contact to the periodontal membrane of an erupted vital tooth. This type of cyst should not be confused with a radicular cyst in a lateral position developing as a consequence of inflammation from an infected or necrotic branch of the pulp canal. Several authors do not differentiate between the lateral periodontal cyst and the gingival cyst, but it seems justified to consider the lateral periodontal cysts as a separate entity of odontogenic cysts. In this origin of the lateral periodontal cyst is reviewed and several possibilities are discussed. It is concluded that the epithelial lining of this type of cysts most probably originates from the cell rests of Malassez. Case report of one lateral periodontal cyst is presented.