Which of the following is not a risk factor for oropharyngeal carcinoma?
Leukoplakia.
Erythroplakia.
Submucous fibrosis.
Lichen planus
Laryngeal keratosis
Actinic cheliosis
Smooth,red tonque of plummer - vinson syndrome.
Chronic hypertrophic candidiasis
Oral submucous fibrosis
Erythroplakia
None of the above