23 hours each day to be effective in correcting the overbite, typically for 12 to 18 months depending on the severity of the overbite, how much it is worn and what growth stage the patient is in. Typically however the prescribed daily wear time will be between 14 and 16 hours a day. Orthodontic headgear will usually consist of three major components: Facebow: first, the facebow (or J-Hooks) is fitted with a metal arch onto headgear tubes attached to the rear upper and lower molars. This facebow then extends out of the mouth and around the patients face. J-Hooks are different in that they hook into the patients mouth and attach directly to the brace (see photo for example of J-Hooks). Head cap: the second component is the headcap, which typically consists of one or a number of straps fitting around the patients head. This is attached with elastic bands or springs to the facebow. Additional straps and attachments are used to ensure comfort and safety (see photo). Attachment: the third and final component – typically consisting of rubber bands, elastics, or springs – joins the facebow or J-Hooks and the headcap together, providing the force to move the upper teeth, jaw backwards. Soreness of teeth when chewing or when the teeth touch is typical. Patients usually feel the soreness to 2 to 3 hours later, but younger patients tend to react sooner, (e.g., 1 to hours). The headgear application is one of the most useful appliances available to the orthodontist when looking to correct a Class II malocclusion. Facemask and reverse-pull headgear Facemask or reverse-pull headgear is an orthodontic appliance typically used in growing patients to correct underbites (technically termed Class-III orthodontic problems) by pulling forward and assisting the growth of the upper jaw (maxilla), allowing it to catch up to the size of the lower jaw (mandible). These appliances effectively serve to pull the patient's teeth forward. Facemasks or reverse-pull headgear needs to be worn between 12 and 23 hours per day, but typically a period of 14 to 16 hours each day is effective in correcting the underbite. Overall wear time is usually anywhere from 12 to 18 months depending on the severity of the bite and how much a patient's jaws and bones are growing over this time. The appliance normally consists of a frame or a center bars that are strapped to the patient's head