Crossbite/blocked disk caused by braces?

Hi - My niece in her 20s had braces on for the last 2 years. In the last 4 months, she's found that her bite is misaligned, in that she has to move her jaw for it to close properly, as if she has a crossbite. She saw a 2nd orthodontist, who believes she might have a blocked disk, and recommended that she see an oral surgeon, and that perhaps she needs a splint. What's puzzling her is how is it possible that she seems to have suddenly developed this problem? Also, the original orthodontist didn't seem to respond at all to her complaints about this problem, so even if the splint helps, she no longer trusts the original doctor, and wants to see someone else. But that would mean paying lots of extra money. Do you think it's possible that a complaint could be logged against the original orthodontist, in order to recover some of the payment? Thanks. - Mark