Oral submucous fibrosis
Oral submucous fibrosis (OSMF or OSF) is a chronic, complex, rarely will it turn ( 1% ) to a precancerous condition of the mouth characterized by juxta-epithelial inflammatory reaction and progressive fibrosis of the submucosal tissues (the lamina propria and deeper connective tissues). As the disease progresses, the jaws become rigid to the point that the person is unable to open the mouth. The condition is remotely linked to oral cancers and is associated with areca nut or betel quid chewing, a habit similar to tobacco chewing, is practiced predominantly in Southeast Asia and India, dating back thousands of years.