Cell proliferation in odontogenic jaw cyst epithelium

Objective: The aim of the study is to investigate the epithelial cell proliferation in the lining of odontogenic cysts with Ki-67 monoclonal antibody.

Methods: Ki-67 expression was studied in 30 odontogenic cysts (odontogenic keratocysts, n = 10; dentigerous cyst, n = 10; radicular cysts, n = 10), and normal oral epithelium (n = 10) by using a biotin streptavidin method on routinely processed paraffin sections after microwave treatment. Ki-67+ cells were counted manually and related to the area of epithelial lining as determined by computer image analyzer. The result was analyzed by using a computer image analyzer to calculate positive cells per square millimeter of the epithelial lining of odontogenic lesions. Data were analyzed by using student test.

Results: The epithelial lining of odontogenic keratocysts contained the highest number of Ki-67+ cells, most of which were located in the suprabasal layers. The mean value of Ki-67+ cells in odontogenic keratocysts linings (1812.29 +/- 606.47 cells/mm2) were significantly higher than that of dentigerous (944.43 +/- 58.98 cells/mm2) and radicular cysts (610 +/- 26.4 cells/mm2) (P < 0.01). Negative reactions were obtained in the normal oral epithelium.

Conclusions: The results demonstrate that there are differences in Ki-67 expression between epithelial linings of the major odontogenic cysts, which were consistent with odontogenic keratocysts having a greater proliferative capability than dentigerous and radicular cysts. It also indicates differences in proliferation and differentiation processes within these lesions.