@fourof5zs @lilypaws I also thought TMJ immediately. When I was much younger, in my 20s, I used to have a problem where my jaw would "lock" for a day or two. I could barely open it enough to eat, I had to squish sandwiches down to get them in between my teeth. It happened off and on and eventually just disappeared! I still have no idea what the cause was so I am interested in finding that out if you do.
JK