I have an underbite, is it severe enough to require surgery? I had braces when I was 16 and had an expander as well. The results were great, but I lost my retainer after a year and my teeth have slowly relapsed (5 years). Do braces work better second time round? I have asthma and I am always congested so I think my mouth breathing contributed to that. I also have these black spots on my molars. What treatments would be best for these issues? Thanks