Always been an enigmatic entity Odontogenic Keratocyst (OKC) is an epithelial developmental cyst derived from enamel organ or dental lamina. In the earlier literature OKC was described as a cholesteatoma (Hauer 1926; Kostecka 1929) with the first account of the lesion given by Mikulicz who in 1876 described it as a dermoid cyst. This book attempts to provide a latest comprehensive review of OKC.