Cyclin D1, a G1 cyclin member, regulates the transition of the cell cycle from the G1 phase to the S phase. The uncontrolled and elevated expression of cyclin D1 has been associated with rapid growth, heightened proliferative activity and increased histologic aggressiveness. Unicystic ameloblastoma pertains to cystic lesions that present clinical, radiographic, or gross features akin to jaw cysts. Nevertheless, upon histological scrutiny, these lesions display a distinctive ameloblastomatous epithelium lining the cystic cavity, with or without luminal or mural proliferation. This cystic variant of tumor bears substantial resemblances to dentigerous cysts, and occasionally, both entities can become indistinguishable upon histological examination. The study aimed to investigate whether the immunohistochemical expression of cyclin D1 in unicystic ameloblastoma, odontogenic keratocyst and dentigerous cyst correlates with their known clinical behavior
