A palatal expander, also known as a rapid palatal expander, rapid maxillary expansion appliance, palate expander or orthodontic expander, is used to widen the upper jaw so that the bottom and upper teeth will fit together better. It works best in teenagers younger than 15 years old, because below this age, the bones of the upper jaw are still pliable. The palatal expander consists of a screw that is attached to the teeth by means of bands that go around your teeth. The expander is activated by turning the screw with a key. As the upper jaw is widened, a space may develop between the front teeth. This space will generally close by itself within a month. Once expansion is completed, the expander will remain in the mouth for approximately three months to stabilize before being removed.
These retainers are removable and used in many situations. When braces are removed these retainers maintain treatment results, close space, or maintain expansion after the use of a palatal expander. The retainers are made with a colored acrylic and have a wire that crosses the front teeth. After braces are removed, the best way to ensure long-term stability of the teeth is indefinite retainer wear.
Essix retainers are clear retainers that are worn following the removal of the braces. They are popular because they are nearly invisible and are very durable. They are custom made for each patient following the removal of the braces.