Head and Neck cancers Support Group
Oral cancer or oral cavity cancer, a subtype of head and neck cancer, is any cancerous tissue growth located in the oral cavity. It may arise as a primary lesion originating in any of the oral tissues, by metastasis from a distant site of origin, or by extension from a neighboring anatomic structure, such as the nasal cavity or the maxillary sinus.
Also try colloidal silver to boost his immune system. It's easy to use and doesn't taste like anything.
One last thing as well... I don't know if you or your dad are spiritual, but there is a healing art called Reiki that you might look into. It doesn't interfere with any religious feelings, it's just pure healing. I've even seen it on some support websites like Wespark.org My fiance does it and it works when I have really terrible pain and neck spasms.
May the Lord bless you and your family and make you all healthy.