Worldwide head and neck cancers occur in 550,000 people with around 300,000 deaths each year. Although head and neck region may give rise to many different histological types of malignancies, around 90% of all cancers affecting this region are squamous cell carcinomas. These are the sixth leading cancer by incidence worldwide. Tobacco, smoked and smokeless, is the most important preventable risk factor. Alcohol is also a major independent risk factor,...