An appliance that is worn after the removal of braces or other orthodontic appliances to stabilize the teeth that have been moved into proper position. The dental retainer is generally used on the upper teeth during an important stage of orthodontic treatment called retention. During this stage, the teeth, which have been repositioned by the braces must be held in place for a period to establish permanently the corrected alignment and bite. The retainer holds the teeth in place as the jaw hardens and the teeth become strongly attached to the jaw. Some removable retainers are constructed of plastic and wire. Others are made entirely of metal wire. The orthodontist who fits the retainer offers individualized instructions on how often and for how long the retainer must be worn, depending on factors including age and the condition of the gums and teeth. Usually, the retainer is worn only at night. If a child who has worn braces is still growing and if all of his or her permanent teeth have not yet erupted, fixed retainers may be bonded inside the lower teeth or cemented to the back teeth.