Teeth can slowly be moved and shifted into proper position by applying pressure in certain directions.
Bands, Wires and elastics are placed on the teeth to move them in the right direction. This takes place slowly and carefully over an extended period of time. Shifting teeth back into a functional position can take months to years, but eventually you will have a new and improved mouth and a longer lasting smile. Retainers are often used after the braces, to hold the teeth in their new position until they are stable.
It is important to wear the braces or an appliance for however long the dentist suggests. If you quit at any point during the treatment, the teeth can shift back into their old position.

