There are three most common precancerous lesions seen in the mouth and they are
1. Oral leucoplakia
It is characterized by white patch on the buccal mucosa or any place in the mouth and is adjacent to the place where the tobacco quid is kept. The less likely place is floor of the mouth and tongue although 93% of leucoplakia at this sites turn malignant.
This is characterized by red velvety patch, which is not associated with any trauma or inflammation. It may present with or without leucoplakia. This lesion is easily missed out but is considered to have great malignancy potential.
3. Oral sub mucous fibrosis.
This condition is characterized by limited opening of mouth and burning sensation on eating of spicy food. This is a progressive lesion in which the opening of the mouth becomes progressively limited, and later on even normal eating becomes difficult.
It occurs almost exclusively in India and Indian communities living abroad.
Professor Newell Johnson an expert oral surgeon said, "we know this condition, oral sub mucous fibrosis has highest rate of transferring to malignancy of any of the so called premalignant lesions in the mouth. it is a very serious condition".