Any life changes? High stress? It hit me once when I was really stressed at work, and chewing tons of gum. Took like a month to get better. It is hard to sleep, you have to sleep on your back looking straight up, you can't sleep on your side because it hurts too much. Take it easy with food and chewing. If you have a blender put it to good use.
Reduce stress, and don't chew gum. It has never come back for me, but YMMV.
Reduce stress, and don't chew gum. It has never come back for me, but YMMV.