Functional Appliances

Functional appliances are devices used to correct a significant disharmony in the relationship between the upper and lower jaws. They work by influencing the growth and development of a growing patient.

The most common use of a functional appliance is to encourage the forward growth of a retrusive or "under-developed" lower jaw. The functional appliance holds the lower jaw forward over a period until the teeth, jaws and joints have "adapted" and the desired jaw position has been obtained.

The effectiveness of a functional appliance depends on:

how much the appliance is worn
how quickly the patient is growing

Functional appliances align the jaws not the teeth, so they are usually used as a first stage of treatment (in a growing patient with a significant jaw disharmony) prior to the alignment of the teeth with fixed appliances (braces).

The most common types of functional appliance are listed below:

Fixed functional appliances:

Herbst appliance (pictured)
Cantilever bite jumper
Fixed Twin Bock appliance

Removable functional appliances:

Bionator (pictured)
Activator
Twin Block appliance
Teuscher appliance
Frankel appliance
Andreson appliance