Cell proliferation markers in the odontogenic keratocyst: effect of inflammation

The immunohistochemical expression of PCNA and Ki-67 proteins and the histochemical expression of AgNORs were studied in 20 odontogenic keratocysts in order to assess the relationship between epithelial cell proliferation and inflammation within the capsule. Immunostained cells were quantified by conventional methods, and both quantitative and morphometric analyses of AgNORs were performed by TV image analysis. Non-inflamed odontogenic keratocysts showed a typical epithelial lining and inflamed odontogenic keratocysts were lined also by hyperplastic non-keratinized stratified squamous epithelium. A statistically significant increase of PCNA+ and Ki-67+ cells and of AgNOR numbers was detected in the linings of inflamed odontogenic keratocysts compared to non-inflamed lesions. The results suggest the existence of greater proliferative activity in the epithelial cells of inflamed odontogenic keratocysts, which may be associated with the disruption of the typical structure of odontogenic keratocyst linings.