Orthodontic retainers are custom-made devices, usually made of wires or clear plastic, that hold teeth in position after surgery or any method of realigning teeth. They are most often used before or after dental braces to keep teeth in position while assisting the adjustment of the surrounding gums to changes in the bone. Most patients are required to wear their retainer(s) every night at first, with many also being directed to wear them during the day – at least initially. There are four types of retainers typically prescribed by orthodontists and dentists: Hawley, Essix, Zendura, and Bonded (Fixed) retainers.
The best-known type is the Hawley retainer, which includes a metal wire that typically surrounds the six anterior teeth and keeps them in place. Named for its inventor, Dr. Charles A. Hawley, the labial wire, or Hawley bow, incorporates 2 omega loops for adjustment. It is anchored in an acrylic arch that sits in the palate (roof of the mouth). The advantage of this type of retainer is that the metal wires can be adjusted to finish treatment and continue minor movement of the anterior teeth as needed.
Recently, a more aesthetic version of the Hawley retainer has been developed. For this alternative, the front metal wire is replaced with a clear wire called the ASTICS. This retainer is intended to be adjustable similarly to the traditional Hawley retainer, which is not practical with vacuum-formed retainers. The original clear bow named QCM, was developed to eliminate the look of wire across the facial surface of the arch. Excessive breakage has made this impractical for younger patients.
An entirely different category of orthodontic retainers are fixed retainers. A fixed retainer typically consists of a passive wire bonded to the tongue-side of the (usually, depending on the patient’s bite, only lower) incisors. Unlike the previously-mentioned retainer types, fixed retainers cannot be removed by the patient. Some doctors prescribe fixed retainers regularly, especially where active orthodontic treatments have affected great changes in the bite and there is a high risk for reversal of these changes. While the device is usually required until a year after wisdom teeth have been extracted it is often kept in place for life. Fixed retainers may lead to tartar build-up or gingivitis due to the difficulty of flossing while wearing these retainers. As with dental braces, patients often must use floss threaders to pass dental floss through the small space between the retainer and the teeth.