We hear this question daily at our office. The real answer is however long you want your teeth to remain straight!We consider retainers to be lifetime appliances. You should see the look of disbelief on patients faces when we say that. While it may sound discouraging, there are reasons for wearing the retainers for the long haul.
Teeth are not static. They are always moving, and they will continue to move and shift even though you've had braces. They will try to move forward, up and outwards. As we age, our teeth move toward the front of the mouth and will get more crowded over time.
So if you are a patient, and just had your teeth moved into their optimal position via braces, those teeth have a strong tendency to relapse into their original position. Teeth actualy have a "memory" of the position they were in before braces. There are ligaments that connect the teeth to the bone and these ligaments stretch as the teeth are moved to their new position.
This is where your retainers come into play! They hold the teeth into place and, over time, the memory of these ligaments will fade. However, teeth are continually moving and shifting - not always to our advantage - and it is wise, once you've attained a functional and aesthetic position and bite with braces or Invisalign , to maintain this position for as long as you can. In fact, Invisalign was first introduced as a product designed to correct adult relapse (for adults who didn't wear their retainers, or didn't wear them for long).
Even years after orthodontic treatment, patients should ideally still be wearing their retainers at night. The retainers not only hold your teeth in place, but protect your teeth from wear and tear by maintining the correct bite relationship of the top and bottom arches. They are lifelong tools for youto use to maintain your beautiful smile!