Immunohistochemical Study on Epithelialization of the Fascial Flap in the Oral Cavity of Rats.

The immunohistochemical expressions of epidermal growth factor receptor (EGFR) and Proliferating Cell Nuclear Antigen (PCNA) were studied in the epithelialization process of bare flaps, the fascial flap and the deepithelialized mucoperiosteal flap, used for reconstruction of the oral mucosa in rat models. The intense expression of EGFR and PCNA was detected in the tip area of the migrating epithelium during the early period of the healing process in both flaps, and differing distributions of EGFR and PCNA positive cells were identified. In the fascial flap, a signifi-cantly high positive rate of EGFR was detected in comparison with the deepithelialized mucoperiosteal flap. The expression of EGFR in both flaps may be attributed to the influences of different connective tissue substrates which induce a control mechanism to maintain the equilibrium between differentiation and proliferation of epithelium.