Focal(frictional)Benign keratosis A white lesion that is related to chronic rubbing or friction aginst an oral mucosal surface.(protective hyperkeratotic white lesion) increase in amounts of orthokeratin and/or parakeratin without the presence of significant cellular abnormalities (dysplasia)

This is the most common of the white lesion

There are no specific clinical features by which you can make a definitive diagnosis. Precise diagnosis of keratotic lesions can be made only by biopsy.

This heavy smoker had extensive keratosis of the floor of the mouth for at least one year. We must always be suspicious that keratotic lesions on the floor of the mouth, lateral and ventral surfaces of the tongue, soft palate, and tonsillar pillars

If a lesion of this type does not heal after the initiation of conservative therapy, biopsy is mandatory.

Normal kerathinized epithelium

Histopathoiogic Features Hyperkeratosis Hyperorthokeratosis Hyperparakeratosis

increased keratin formation and acanthosis. Normal The cells are uniform and no dysplasia is present. A few chronic inflamatory cells may be seen

an extremely prominent granular cell layer The granular cell layer is generally found only beneath mature orthokeratin and not parakeratin.

What type of hyperkeratosis is seen ? Hyperorthokeratosis

What type of hyperkeratosis is seen ? Hyperparakeratosis