Why do teeth move after braces?

Teeth always follow the path of least resistance, so if nothing is holding them in place, your teeth are liable to move. There are many reasons why your teeth shift after you’ve worn braces. Every day your teeth are under different pressures, when you speak, your tongue repeatedly presses against your teeth, when you chew, your teeth come under repeated pressure, even when you smile or sneeze, various muscles in your mouth and your face move. Over time, this can affect the position of your teeth. Besides these factors, things like ageing, grinding your teeth in your sleep, and even genetics can affect the position of your teeth. The only thing that can be done to stop teeth shifting is to wear a retainer.