I just got my 2nd set of braces (the 1st time I just had braces on 4 teeth, now I have my whole mouth) last year, and for a while there was nothing wrong. But now, the gums between the 2 molars in the back on the top-right side of my mouth are REALLY sore. Used to they would just hurt when I ate crunchy foods like chips. But now I can't even chew ANY type of food on that side of my mouth. My dentist said it was nothing but I know she's wrong. Do I have a cavity between my molars? And how do I fix the problem? Because it's starting to effect my 2 back top-left molars and soon I wouldn't be able to chew any food at all!