Functional appliances are used in growing children usually around the age of 9 to 12 years. This type of interceptive orthodontics uses the child natural skeletal development to help guide the growth and positioning of their jaws. Functional appliances can be fixed (quad helix or maxillary expander), removable plates (twin blocks) or a cantilever bite jumper. Headgear may also be worn for correction of small lower jaws. These appliances are used to balance the jaws, improve the bite, create space for teeth and correct growth discrepancies. Functional appliances are commonly used to improve overall jaw health and alignment, improve our ability to chew, and aesthetics of the teeth.