The purpose of headgear is to provide extra anchorage to move teeth into a better position. Headgear is used to correct overbites and underbites. The apparatus is most often used by children and preteens because their jaws are still growing. Headgear that has a strap behind the neck or head is using the entire head for anchorage, while headgear that comes over the forehead or chin is pulling the teeth forward.
Headgear operates by applying a specific amount of pressure on the jaw. It is placed at particular angles in order to hold the upper jaw back. This ultimately allows the lower jaw to grow into the correct position, fixing the overbite. Upper molars may also be moved further back into the mouth by headgear to correct overbites. To correct an underbite, the headgear either pulls teeth backward and upward, or forward.
Adults generally use the headgear for different reasons than children, including when teeth are extracted and the front teeth are being pulled backward. The headgear can help hold the teeth behind the extraction back, so they do not slide forward, affecting the bite.
For headgear to be effective, it is worn for approximately 10-14 hours every day. The process of wearing the headgear can last anywhere from six to 18 months. The length of time usually depends on the severity of the overbite that needs adjustment and how much the patient is growing.