Most of us get our braces on during junior high. We are about 12 years old when that last baby tooth falls out and the orthodontist tells us it is finally time. Since most orthodontic treatment lasts about two years, our braces come off right around the time we start high school. Then it happens! Our wisdom teeth come in when we are juniors or seniors and they screw everything up… or do they? What is the relationship between the wisdom teeth and the teeth getting crooked after braces?
Because lower front teeth seem to start getting crooked about the same time that the wisdom teeth come in, they have always gotten a bad “rap.” Are the wisdom teeth to blame or is it just an unfortunate coincidence? Here’s what we know. In research done at the University of Iowa by department head Dr. Tom Southard, it was found that the wisdom teeth DO NOT exert enough pressure on the teeth in front of them to cause them to get crooked. His research involved placing sensors between the teeth that compared the pressures with and without wisdom teeth. There was no difference.
In other studies, the amount of change that occurs in the alignment of teeth after braces in kids with and without wisdom teeth was compared. Some still had wisdom teeth, some had them removed, and some never had them. The results were exactly the same. There was no difference suggesting that wisdom teeth were NOT the key factor in relapse.
So if it isn’t the wisdom teeth, then why do the teeth start getting crooked around 17, 18, or 19 years of age? Orthodontists believe that there are several factors that come into play. First, as the teeth begin to wear the bite deepens in front (the teeth overlap more). This allows the back surface of the upper teeth to press down on the fronts of the lowers pushing them towards the tongue. This deepening of the bite also causes extra wear on the lower front teeth in some patients. The second factor is what orthodontists call late residual growth. In common terms, there is a slight amount of lower jaw growth that happens in the late teens or early 20’s that forces the teeth slightly forward and upward into the backs of the upper teeth. The result is added pressure that crowds previously straight teeth.
So what is the key to keeping the teeth straight? Although there are other reasons for removing your wisdom teeth, keeping your teeth straight really shouldn’t be the main concern. Research indicates that long-term retainer wear is the only “sure thing.” Just like keeping your weight under control after Weight Watchers requires maintenance, keeping your teeth straight after braces requires wearing your retainers for as long as you want them to stay that way!
Dr. Greg Jorgensen is a board certified orthodontist providing braces and Invisalign to children, teenagers, and adults in Rio Rancho, New Mexico and Westside Albuquerque. He also lectures nationally on practice management, information technology, and current treatment techniques in orthodontics.