Cystic and cystlike lesions of the mandible are primarily ellipsoid, radiolucent, and clearly demarcated and may be odontogenic or nonodontogenic. Odontogenic cysts are found in the jaws arising from epithelium involved in tooth formation. They include dentigerous (also known as follicular), lateral periodontal, and radicular cysts. A follicular cyst is a unilocular, osteolytic lesion that classically incorporates the crown of an unerupted tooth; also, it may give rise to ameloblastomas and, in rare cases, undergo malignant transformation. Careful consideration of the patient's history and the location of the lesion within the mandible, as well as the lesion's borders, its internal architecture and structures, and its effects on adjacent structures, generally make it possible to narrow the differential diagnosis.1