I had braces for a year, then I got them off (this happened a couple years ago). New teeth grew in the back (wisdom teeth) and I didn't wear my retainers for some time so the teeth moved. A month ago or so I got braces again, and I have to wear them for another 5 months.
I go to a place called fastbraces, and surprisingly, my teeth aren't even sore. The time I experienced the most pain was when I got the actual braces put on, and the week after I got them on.