Histopathological Oral Tissues Changes of Rats Exposed to Tobacco Smoke

Objectives: the purpose of this study was to evaluate the histopathological changes in oral tissues of rats exposed to tobacco smoke. Methods: 20 female rats Sprague Dawley were included in the study and 10 rats exposed to environmental tobacco smoke of 10 cigarettes daily for 4 months. All animals were sacrificed and tissues extracted, died using H&E and finally evaluated under light microscope. Oral mucosa and bone tissues were described and compared statistically using SPSS 17.0. P values<0.05 were considered statistically significant. Results: oral mucosa of rats exposed to tobacco showed augmented epithelial changes as basal hyperplasia basal (p= 0,001), acanthosis (p= 0,0001), nuclear hyperchromatism and picnosis (p= 0,010 y 0,014 respectively), and epithelial dysplasia (p=0.0001). Increased chronic inflammatory infiltrate was also observed in this group (p=0.007), as well as, a higher number of blood vessels although difference was not statistically significant. Conclusions: tobacco inhalation showed to produce tissue alterations of macroscopically healthy mucosa of rats. Cellular and structural changes, clinically imperceptibles, may progress into carcinomas if tovacco exposure persists. Results suggest that visual inspection of the oral cavity is not enough to detect early stages of potentially malignant disorders related to smoking.