Oral cancer, also known as mouth cancer is a type of head and neck cancer recognised by any cancerous tissue (ulcer/growth) located in the oral cavity. The oral cavity where growth takes place includes the following:

• The front two thirds of the tongue.
• The gingiva (gums).
• The buccal mucosa (the inner lining of the cheeks).
• The floor (bottom) of the mouth under the tongue.
• The hard palate (the roof of the mouth).
• The retromolar trigone (the small area behind the wisdom teeth)

Most (90%) oral cancers look very similar under the microscope and are called squamous cell carcinoma. Alternatively, the oral cancers may originate in any of the tissues of the mouth, and may be of varied histologic types.

Not all tumors in the mouth are cancers. Some are benign (simple/non cancerous) and some others are precancerous (potential to get converted into cancer in future)