MATERIALS AND METHODS: Thirty Rattus norvegicus will be exposed to two kinds of cigarette smoke by a smoking pump for 4 and 8 weeks. The tongues were collected to analyze the number of macrophages, lymphocytes, and plasma cells with hematoxylin-eosin. The MMP-9 expression was similarly analyzed with immunohistochemical staining and then compared with the control group.
RESULTS: The number of macrophages, lymphocytes, and MMP-9 expression was higher in the 8-week cigarette smoke exposure compared to the 4-week cigarette smoke exposure and the control group (p < 0.000). The number of plasma cell did not differ in the 8-week cigarette smoke exposure from that of the control group (p > 0.05). The number of plasma cells in the tongue tissue during the 4-week cigarette smoke exposure was not determined.
CONCLUSION: Cigarette smoke exposure induces the risk of oral cancer development as a result of an increase in the number of macrophages, lymphocytes, and MMP-9 expression in the tongue epithelial.