dentigerous cyst /dentij″ərəs/ [L, dens + gerere, to bear] , one of three kinds of follicular cyst, consisting of an epithelium-lined sac filled with fluid or viscous material that surrounds the crown of an unerupted tooth or odontoma. It is the most common type of developmental odontogenic cyst that develops due to inflammation in contact with remnants of the enamel organ or follicular sac that surrounds an unerupted permanent tooth. Radiographically, it appears as a well-defined radiolucent lesion with a radiopaque border attached to the cervical area of an unerupted tooth. Treatment is excision. Compare primordial cyst.