Odontogenic jaw cysts: light and electron microscopical investigations.

Light and electron microscopy were used to analyze the epithelial lining of odontogenic cysts excised from edentulous regions of the jaws. Clinically, three cases were identified as keratocysts, and 21 cases as cysts other than keratocysts ("non-keratocysts"). The epithelium of the former was found to achieve keratinization over most of the surface and to never contain mucus secreting cells. The epithelium of the latter appeared to be in part stratified squamous, with cells loosely connected to each other, and in part stratified columnar, with superficial cells connected to each other by tight junctions and secreting mucus. The results suggest that cysts arising from edentulous regions of the jaws may be either keratocysts or cysts with heterogeneous, non-keratinizing epithelium; the content of keratocysts can be formed mainly by shedding of cornified epithelial layers, and that of non-keratocysts by mucus secretion from columnar epithelium associated to fluid filtration through non-keratinizing squamous epithelium.