Your teeth/gums are no more likely than a 12 year old to have complications from orthodontics. Orthodontic treatment will improve you smile and prevent any further wear from your severely overlapping bite. I have treated several patients in their early and mid eighties and they all love the visible improvements for a relatively small hassle. Compared to some of the other aspects of getting older, straightening your teeth is a really simple, non invasive thing to do.Side note: When you are finished with treatment and you have had the worn edges of your upper teeth smoothed and the corners rounded (which a good orthodontist will probably do as part of your treatment) your smile and thus the lower half of your face will look much younger.