Why Can Teeth Move Back After Braces?
During your treatment, your teeth are held in place by the therapy appliance. For braces, they are permanently held in place by the brackets and wires; for Invisalign, they are held in place with the clear aligners worn 22 hours a day.
When the appliance is over, the pressure holding your teeth in place is removed. Some settling is natural as your teeth find their place, and this can cause shifting out of the alignment created by orthodontia.
That ??s where retainers come in: they are the key to continuing enough pressure to keep your teeth in place post-treatment!