Kelly, I would ask my dentsit for a referral to an oral surgeon for a second opinon on that sore in your mouth. If he thinks it is worrisome, he can biopsy it and tell you shortly there after in black and white if it is something serious or not. As to seeing the doctor about your nasal drainage and the type of doctor you are going to see, my gut impression is that a separate issue and not the kind of doctor that is going to make an evaluation if you have an oral or oropharygeal cancer or not. I am somewhat disturbed by your symptoms as we sometimes see these things, the sore/spot in your mouth, the throat pain, the ear ache. I am not sure why you are thinking something in your sinus and looking into that, since the only thing you have is drainage, and that could be from anything from a bacteria or virus to just irritation from allergy. I think you need to have that spot in your mouth evaluated by someone who is not just going to be puzzled by it. That dentist should have referred you for another opinion, not just let it go undiagnosed.