Functional Appliances
Orthodontic devices that modify jaw growth in growing children.
Functional appliances are orthodontic devices that harness and redirect the forces of facial muscles and jaw growth to correct skeletal discrepancies. They are most effective during the pubertal growth spurt (ages 10-14 for girls, 12-16 for boys). These appliances work by posturing the lower jaw forward in Class II malocclusion or restraining upper jaw growth in Class III cases. Common functional appliances include Twin Block (most popular, two removable blocks), Herbst appliance (fixed, telescoping arms), Bionator (single removable piece), Frankel appliance (vestibular shields), and mandibular advancement devices. Treatment typically lasts 9-15 months. Research shows functional appliances can produce 2-4mm of additional mandibular growth beyond normal.