A rheumatoid arthritis flare in my shoulder bad enough to cause a dislocation. They can't just pop it back in when it's pushed out from the inside, just have to wait for the steroids to kick in and hope for the best. It took 6 months of physio to get 95% range of motion back. But I'm feeling much better now (and just finished a season of night court on dvd from my local library).
Not OP but the dentist thought the nerve was dead so didn't bother. It's one of my clearest childhood memories from more than 40 yrs ago and was the worst for me until about 10 yrs ago.