Hi--this is my worst nightmare too since my daughter is going into ortho. work as well. I'm so sorry to hear about what she is going through. It sounds like the oral surgeon, or the orthodontist for that matter dislocated one of her discs, or heaven forbid her teeth weren't put in the right position. This is exactly how my tmj started. You will need to get her an MRI probably to make sure where her discs are, --if the surgeon opened her too wide, he might have dislocated or damaged a disc. When she is popping her discs are being displaced and the actual pop I believe is the disc coming back into position. This is serious because if she begins locking, sometimes this can cause damage if you try to force the jaw open. If she does happen to lock, have her gag herself pretty hard. Sometimes this will recapture your disc and then you will know right away if you can open normally. It saved me at least twice in my life, so I'm Proof that it does work. Get all her x-rays and medical info. from her ortho. and surgeon, especially if you are entering into legal issues. Document everything. If it were my daughter, I would get her an MRI immediatly and find the best tmj specialist who is also a functional jaw orthodontist to get a consult with.
I don't want to freak you out., but this is extremely serious and what you do right now will make or break her chances of developing full blown tmjd in the future. You need a good specialist's consult. I wish you both the best of luck------J.