I get a weird sharp pain in some glands or something down in the corners of my mouth, at the bottom of my jaw, after eating too much fatty and sweet food, sometimes from fish n chips. Whenever I try to explain it to people I get a blank look, I've never met a fellow sufferer. I used to get it when I was a kid if I ate chocolate directly after crisps without having a drink. It's quite unpleasant. I guess it's fat jamming up the saliva glands or something. Not sure how this helps you but we should probably eat more healthily.