Functional appliances work by using what to move the jaws?

Functional appliances are designed to facilitate the growth and development of the jaws by utilizing muscular forces. These devices encourage the patient to use their own muscle activity to create the necessary adjustments in jaw position. For example, when a patient bites or closes their mouth, the muscles exert force on the appliance, which then influences the positioning of the jaw. This can ultimately lead to changes in the dental alignment and jaw relationship over time.

Mechanical forces, while relevant in orthodontics, do not accurately describe how functional appliances achieve their purpose. Similarly, chemical forces do not play a role in jaw movement, as they pertain more to reactions at a molecular level rather than physical jaw positioning. Gravity is also not a primary mechanism in the intended function of these appliances, particularly since their success depends largely on the active participation of the patient's muscles. Thus, muscular forces are central to the way functional appliances operate to achieve dental and orthopedic changes.