SCANNING ELECTRON-MICROSCOPY OF DIFFERENT TYPES OF ORAL LEUKOPLAKIA -COMPARISON WITH NORMAL AND MALIGNANT ORAL-MUCOSA

The present study analysed surface architecture of normal, premalignan t and malignant oral mucosa using scanning electron microscopy to eval uate its role in early diagnosis of potentially malignant oral lesions . The surface ultrastructure of the buccal mucosa in tobacco chewers s howed variations from that of non-chewers. Homogenous leukoplakia demo nstrated well-defined intercellular junctions and the microrugal surfa ce pattern as seen in normal mucosa. In verrucous leukoplakia, the sur face layer consisted of characteristically-shrunken desquamated hyperk eratotic cells. Erosive leukoplakia had a discontinuous superficial la yer along with complete loss of intercellular ridges. Speckled leukopl akia also showed marked abnormalities such as thickened irregular prot rusions and evidence of a villuslike pattern. These villus-like struct ures were comparatively prominent in leukoplakia showing dysplasia. Or al carcinoma showed marked altered surface ultrastructure and had a pa ttern similar to dysplastic lesions. The irregular swollen elongated p rotrusions with villous-like structures that were observed in carcinom a and dysplastic lesions can, therefore, be considered as surface mark ers for potentially malignant leukoplakia.