My problems came about right after I had a wisdom tooth pulled..I've never been formally diagnosed with masseteric hypertrophy, however, my cheek/jaw muscles have overdeveloped to an alarming extent since this happened..first just my left, then my right one as well. It basically looks like I just had my wisdom teeth removed...but it never goes away.

Are you having pain issues? If it's mainly an appearance thing, personally, I would go with botox. If you go to a search engine and type in "jaw reduction" and "botox" or masseter hypertrophy and botox, you can find some pretty persuasive before and after photos. It mainly seems to be done on asian patients, however, I've seen some photos of caucasions who have overdeveloped muscles due to tmj issues and they look great in the afters. I don't really have any knowledge on the steroid injections though. Good luck.