Cytokeratin intermediate filaments in oral and odontogenic epithelia

With the development of monoclonal antibodies, the intermediate filaments of the cytoskeleton have attracted a great deal of interest in the last twenty years. Because they are highly antigenic, they could be easily identified using immunohistochemical methods and their specificity for one type of cell offered possibilities in the field of diagnostic pathology. The intermediate filaments most specific for epithelial cells are the cytokeratins (CK). After CK were classified, and certain "rules" regarding CK defined, research proceeded a pace to investigate epithelia in a vast array of anatomical and pathological situations. However, much of the immunohistochemical data that was generated during the 1980's was difficult to digest and some difficult to interpret. Reasons for this include identification of CK by molecular weight rather than CK number, or confusion as to which CK were being labelled by a particular antibody clone known to detect more than one CK. The aim of this article is therefore to present a digest of current knowledge of the CK present within the epithelium of the oral cavity (including the odontogenic epithelium) and its glandular component, and to highlight the significance of the CK phenotype in our understanding of pathological change.