Dr. Nate here this week to explain why you need a retainer after braces. Simply: teeth move. It doesn't even matter whether you've had orthodontic treatment or not. As long as you are alive, your teeth will shift over time. There are two main reasons why teeth move...
Let's first start with physiology. Teeth are surrounded by bone, but that bone is subject to the forces of biting (occlusion). So while teeth feel firmly attached to your head, they are part of a mini-earthquake every time you bite down. This constant change can cause teeth to shift with time.
As for the second reason, I have to start with some orthodontic research. Adults who had braces back in the early 80's will tell us that they were told long ago that retainers didn't need to be worn forever. And they are correct.
But, just as anything else in medicine and dentistry, our treatments are based in the best AVAILABLE research. And up until 1985 orthodontists were recommending retainers be worn for "a few years."
In 1985, an orthodontist named Rolph Behrents published a paper called "Growth in the Aging Craniofacial Skeleton" that definitively showed that faces continue to grow throughout a lifetime. Now understand that this growth is minimal, say 1mm over a 10 year period. But believe me when I say this paper was revolutionary in terms of dictating future orthodontic treatments, especially in the area of retainers.
Why would a small amount facial growth affect tooth position? Dr. Behrents showed that facial growth isn't symmetrical between the upper and lower jaws. Instead the lower jaw grows more than the upper jaw. This tends to put stress on the lower front teeth, and causes them to crowd. This is why adults most often notice that their lower teeth have moved more than the upper jaw counterparts. Again, this is an insidiously slow process. But it is one that over 10 years will cause you to notice that your teeth have moved. So, how do we combat this?
At the end of orthodontic treatment, we give our patients retainers. In a future blog post, we will discuss the different retainer types. These retainers do exactly what they say. They retain position. Our instructions are clear-wear your retainers as long as you want your teeth to stay straight.
If you've had orthodontic treatment in the past, and have lost or stopped wearing your retainers, we would recommend that you find a way to get new ones. It is a simple solution that could help you avoid more complicated problems later.