i was going to say that if you can afford it anyhow, it's worth it. I had TMJ about 10 years ago, did not have to go on steroids at all.
Just got fitted for a mouthpiece. At that time, tmj wasn't covered by any insurance, so it was all out of pocket for me (or on credit card, as it was). I cursed it at the time, but I'm glad I did something about it. My jaw and the cartilage was pretty badly damaged, and I only went in when I finally couldn't open my mouth very wide. I still use a mouthpiece, although now it's for keeping my teeth from grinding together. But since my jaw is re-aligned, the grind-prevention mouthpiece does the job of both (keeps jaw aligned as well).
Only time I ever had to go on prednazone was for a seriously bad case of poison ivy (just got clipless pedals and went on a single-track). bad idea...