STK typically occurs in the buccal sulcus (inside the cheek) or the labial sulcus (between the lips and the teeth) and corresponds to the site where the<unk>  is held in the mouth. It is painless. The appearance of the lesion is variable depending upon the type of<unk>  used, and the frequency and duration of use. It takes about 1-5 years of<unk><unk>  use for the lesion to appear. Early lesions may appear as thin, translucent and granular or wrinkled mucosa. The later lesion may appear thicker, more opaquely white and hyperkeratotic with fissures and folds. Oral snuff causes more pronounced changes in the oral mucosa than<unk>  chewing. Snuff dipping is associated more with verrucous keratosis. As well as the white changes of the oral mucosa, there may be gingival recession (receding gums) and staining of tooth roots in the area where the<unk>  is held.
Smokeless tobacco keratosis
Hydrocarbon keratosis
Arsenical keratosis
PUVA keratosis
Actinic keratosis
Reactional keratosis
Occupational acne
Seborrheic keratosis