Headgear is an extraoral (outside the mouth) appliance that connects with the teeth and jaws through braces or other inside the mouth appliance, to apply force to the upper jaw.
Headgear with straps that go around the neck or the back of the head are designed to pull the upper jaw back. This kind of headgear is very rarely used any more.
Headgear that has a support on the forehead and chin with elastics stretching from a framework attached to these supports to the upper teeth is designed to pull the upper jaw forward.
This kind of headgear is still used in the attempt to bring the upper jaw forward to properly match the lower jaw and is called “reverse headgear” or “face mask headgear”.
To work effectively, headgear must be worn 12 to 14 hours a day and this can be a challenge with the busy lives that kids lead these days.