Had to wear an expander for about 6 months, both top and bottem. Wasn't exactly "painful", but very irritating. Got those off and immediately put on top and bottem braces. Had those for 2 years, then got retainers. Now I have braces again, 5 years later. This time I snagged some ceramic braces (Instead of metal). So basically they are clear, but not "invisalign". Don't know how long I will have those on for, because I have to wait for a tooth to come down ( Top jaw was to small so tooth could not come down because it was blocked by another). The good news is that it is 1/2 way down. Yay for me...