Retainers are removable plates or wires given to prevent teeth from moving after the orthodontic treatment is completed. The teeth have a tendency to shift from their corrected positions as the bone supporting them is softer when the braces are removed and also there are a number of forces acting on the teeth. A retainer supports the teeth and keeps them in their corrected positions.
Usually the retainers are worn at least for a year and are gradually weaned off. In some cases longer retention may be necessary for the long term stability of the results.