hi there i have fixed braces on top and bottom, im 13, and as i first had them put on, they hurt like hell, the best things to use to relive the pain is bongella (for blisters) and bathy tething gel works really well, when i first had them put on i post an answer up here aswell, but it depends how bad it is, if you only have a few of your bottom jaw needs moving about, it should be just under a year, but if i were you i wouldent take this advice as you never know. i would phone my orthodist up, ps back to your jaw hurting, coffe and other hot drinks are exellent, as you probabbly know, heat expands metals, which lossens your braces up! (i learnt that in science) lol and if your toothbrush is hurting, use an electric one, i have oral-b proffesional care, and for best cleaning results for metal and your teeth youse duraphat toothpaste, it is recomended by alot of orthodist.
lots of people have taken my advice on braces, as i have had them for 2 months, and i need them in for a year, the pain will go in about a week.
~ ROBERT TAYLOR ~
P.S hope you have found an answer!