PATHOGENESIS OF THE CALCIFYING ODONTOGENIC CYST (GORLIN-CYST)

Four new cases of calcifying odontogenic cyst (COC) were studied by light- and electronmicroscope. The ages of the patients were between 20 and 68 years. Three cysts were located in the maxilla, the other was in the mandible. The history of two patients was followed up for five and ten years respectively. The longer the history the bigger were the cysts. All cysts showed histologically identical alterations of the epithelium with 1) a pronounced cylindrical basal cell layer, 2) cells resembling stellate reticulum, and 3) ghost cells. So called dysplastic dentin was laid down in the connective tissue only in the two cases with a long history. Ultrastructurally the odontogenic epithelium of all cysts showed keratinization similar to the epidermis. Two types of keratinization are known to occur in the epidermis, soft keratinization with keratohyalin granules in ortho- and parakeratosis, and hard keratinization without keratohyalin granules in nails (horn). Both types of keratinization occur in odontogenic epithelium. The COC is an example of hard keratinization. Ghost cells form prekeratin which in turn becomes horn and is found in areas of confluent ghost cells and in the so called dysplastic dentin. We conclude that the alteration of odontogenic epithelium in COC and in special odontogenic tumors is a secondary phenomenon resembling ortho- and parakeratosis. © 1979 Springer-Verlag.