I don't think having braces is a dealbreaker nor should it be an impediment. Braces are merely something cosmetic to enhance a person's smile etc. I think the only thing the couple will have to work out is kissing...I am not sure how or if the braces will impact that.
Ha ha, Personally, Looks aren't everything. If you can make me laugh and have something going for you then that's the true deal breaker. andd besides, Braces aren't forever. If a girl can't look past that, then she's not even worth it.