It may feel like a magic trick as you watch crowded teeth magically move around and create a beautiful smile.

How it happens!
The reason we are able to do move teeth is because the bone that teeth roots sit in can be reshaped or remodeled.
As teeth move through bone a process occurs where bone on one side to the tooth dissolves and on the other side of the tooth bone forms. Without this process broken bones would never heal.
Braces and other orthodontic appliances move teeth by exerting a constant light pressure on the bone.

We need space
Often teeth can not be straightened or moved to the "correct" place without making some space into which the teeth can move. Sometimes "baby" teeth and sometimes adult or permanent teeth are removed. This is usually done by the dentist under instructions from the orthodontist.
Unfortunately just because we create a space teeth won't necessarily move into it and the most common method of getting teeth to move is "bands" or "braces".

Sometimes when a space is made next to a tooth through extraction the remaining teeth tilt or rotate into the space. Orthodontists are sometimes asked to upright these tilted teeth so bridge can be used to close the gap.