Assessment of cytological atypia, AgNOR and nuclear area in epithelial cells of normal oral mucosa exposed to toombak and smoking

The purpose of this study was to assess cellular proliferative activity of clinically healthy oral mucosal epithelial cells of toombak dippers and smokers by means of AgNOR counts and nuclear areas via nuclear morphometry. Smears were collected from normal-appearing mouth floor mucosa and tongue of 75 toombak dippers, 75 smokers and 50 non-tobacco users between the ages of 20 and 70 with a mean age of 36 years. AgNORs were counted in the first 50 well-fixed, nucleated squamous cells and nuclear areas were calculated via microscopic stage micrometer. Cytological atypia was ascertained in 6 tobacco users and could not be ascertained in non-tobacco users. Statistically mean AgNOR numbers per nucleus in the non-tobacco users (2.45±0.30) was lower than the toombak dippers (3.081±0.39, p<0.004), and the smokers (2.715±0.39, p<0.02), and mean nuclear areas of epithelial cells of toombak dippers (6.081±0.39, p<0.009) and smokers (5.68±10.08, p<0.01) was also significantly higher than non-smokers (5.39±9.4). The mean number of nuclei having more than 3 AgNORs was 28%, 19% and 7% in toombak dippers, smokers and non-tobacco users, respectively. These findings support the view that toombak dipping and smoking are severe risk factors for oral mucosal proliferative lesions and exfoliative cytology is valid for screening of oral mucosal lesions.