Retainers "retain" or hold the teeth. I use retainers for several different reasons:
After an early treatment phase, to hold the correction until you are ready for full braces
To actively move teeth that can be moved with a removable appliance (in this situation I am calling them retainers but they are really active appliances)
To hold teeth in their corrected positions after braces are removed
There are many different kinds and designs of retainers. (They also come in many colors). The one that I use most often is called a "Hawley" retainer.
