The epithelial-mesenchymal transition (EMT) is described as a rapid and reversible process of change of cell phenotype seen during embryonic development, organ fibrosis, and tumor progression. EMT was first described by Gary Greenberg and Elizabeth Hay in 1982. During EMT the epithelial cells alter their cell polarity, reorganize their cytoskeleton thus become isolated and motile. Depending upon the biological context in which they occur, EMT is divided into three types namely EMT type I, II, III. The article describes the process of EMT implicated in the oral cavity as in palate and root development (type I EMT), gingival fibromatosis and oral sub-mucous fibrosis (type II EMT), and oral squamous cell carcinoma (type III EMT). The reverse p...