Despite improvements in therapy, head and neck carcinomas still have a poor prognosis with a 5-year survival of ~ 50%. Malignancies of the head and neck area are (almost) always preceded by precursor lesions. Treatment of these premalignant mucosal abnormalities is generally limited and not very inconvenient for the patient. If this precursor lesion remain untreated, it may develop into a malignancy of the head and neck. Extensive treatment will be necessary. This means loss of function of the mouth, eg chewing, speaking and swallowing.