Introdouction: Lichen planus is a chronic, relatively common, dermal mucosa disease. The World Health Organization (WHO) has introduced lichen planus as a premalignant condition. Ki-67 is a protein that can be detected in all active phases of the cell cycle, especially in the G2 and M phases. Considering the major role of Ki-67 in the regulation of the cell cycle and the fact that it is one of the conditions for pre-malignant potential and epithelial proliferation, the aim of this study was to evaluate Ki-67 expression in oral lichen planus (OLP) lesions.
Materials and methods: This study included 32 patients [16 with OLP and 16 with no OLP and a normal epithelium, which were considered the control group (CG)]. Demographic data was extracted from each patient’s file and documented in an information form. Immunohistochemistry for Ki-67 was conducted using the EnVision method. P value was significant at <0.05.
Results: Ki-67 staining quality in the OLP group was significantly greater than the CG group according to both the Mann–Whitney test and quantity (p = 0.001). The average percentage of positive cells in the OLP group was 13.11, while the average in the CG group was 2.26. Ki-67 staining in OLPs was 87.5% (++) and 62% with a strong degree of staining. Age and gender differences were compared using the independent t-test no significant statistical differences were noted between the two groups.
Conclusion: Considering Ki-67 is a proliferation marker, the increased expression of Ki-67 in the OLP group’s epithelium indicates a high proliferation rate in lichen planus lesions.