I just got back from my first diving trip with braces last month. I had the kind of regulator with the bite pieces on the sides (between the molars) and just a bumper up front between my incisors and my lips. I didn't have any problems at all. However, if you have additional hardware (bite plate, bionator, elastics), I'd definitely try out the regulator with the hardware before you go under water.
I would also recommend that you not get an adjustment very soon before your dive trip, if you're planning on doing lots of dives. I would imagine that so soon after getting braces, your teeth are still pretty achy for a few days after adjustment, so even that minute amount of pressure from holding your regulator in your mouth might be uncomfortable.
I noticed that after surfacing, my braces actually felt more comfortable for a few hours than they usually do.
I would also recommend that you not get an adjustment very soon before your dive trip, if you're planning on doing lots of dives. I would imagine that so soon after getting braces, your teeth are still pretty achy for a few days after adjustment, so even that minute amount of pressure from holding your regulator in your mouth might be uncomfortable.
I noticed that after surfacing, my braces actually felt more comfortable for a few hours than they usually do.
