I've been having trouble swallowing lately. Everytime I swallow, my mouth tingles (like when you eat something sour.) I noticed that there is a tiny hole on the inside of my mouth, under my gums. I can fit my tongue in there. I think that this is the cause of the mouth pain because saliva is getting in there. I'm afraid of what this might be, but some people have told me it might be a canker sore. It's not really a sore, but a hole. Has anyone had this or know of what it might be? Thanks.