Abstract: Objective: To assess the expression of α-smooth muscle actin(α-SMA)and its clinical significance in oral lichen planus. Methods: Fifteeen cases of normal control, 22 cases of oral lichen planus, and 15 cases of oral squamous cell carcinoma were enrolled in the study. Immunohistochemical analysis was used to detect the expresssion level of α-SMA. Results: The expression level of α-SMA in erosive oral lichen planus, nonerosive oral lichen planus, and oral squamous cell carcinoma were higher than that in nomal control (P＜0.05). The expression level of α-SMA in OSCC was higher than that in OLP (P＜0.05). There was no statistical difference between erosive and nonerosive oral lichen planus (P=0.279). Conclusion: High expression of α-SMA was related to oral lichen planus and OSCC, which may be involved in the malignant transformation of oral lichen planus.

Key words: Oral lichen planus, α-smooth muscle actin, Immunohistochemistry