allowing the patient to open and close his or her jaw. In some cases surgery is required in conjunction with a facemask or reverse-pull headgear. Many parents and doctors recommend using early intervention (typically between ages 7 to 13) by using a facemask to avoid costly and painful surgical procedures later. The appliance is very effective in correcting Class III orthodontic problems in younger or adolescent patients that are still growing. Initially, it can be difficult for children to wear a mask or headgear, however most doctors and parents agree that children and adolescence adapt quickly to such changes and requirements. Parents should be aware that their child is often better-off wearing a facemask or headgear to avoid later surgery and the patient, friends and school peers normally get used to the new appliance after just a few weeks of wear. Adverse effects and controversy Researchers who have studied the long-term effects of orthodontic headgear have found that it may flatten the face and prevent the chin from coming forward, pushing both the upper and lower jaw down and back, into the airway. In more technical terms, it inhibits the natural growth of the jaws and lead to a reduction in the SNA and ANB angles, which relate to the forward position of the maxilla and the mandible. These measurements are good indicators of the size of a person's airway. The controversy about headgear intensified beginning in the 1980s when formerly headgear treated patients developed severe health symptoms, such as sleep apnea, breathing problems and acute TMD. In some cases, eye injuries have been reported, which is minimized with the use of safety release straps and safety facebows. Teenagers prescribed orthodontic headgear often face social stigma and bullying if seen wearing these appliances. Because of the difficulties in complying with daytime wear of headgear, these appliances are mainly worn in the evenings and while sleeping. The need for headgear in orthodontics and its application by practitioners has somewhat decreased in recent years as some orthodontists use temporary implants (i.e., temporary anchorage devices) inside the patient's mouth to perform the same tooth movements. However, the headgear is still widely used and a very effective appliance used by orthodontists today. Soreness of teeth when chewing, or when the teeth touch, is typical. Adults usually feel the soreness 12 to 24 hours later, but younger patients tend to react sooner, (e.g., 2 to