A functional appliance is a type of brace to correct a "Class II" problem; Class II problems are a group of bite problems where the top teeth bite in front of the lower teeth. Functional appliances may be either fixed or removable. Removable functional appliances are most popular in the world. The more common removable functional appliances are made from separate upper and lower parts, which interlock placing the lower jaw in a more advanced position. Other types of functional appliance are made from just one piece, although these may adapt slightly less well to the teeth.

Are there alternative to functional braces?

There are; however, correction of prominent top teeth (Class II) is not straightforward and relies on co-operation from you or your child. Simply placing train track braces is usually insufficient as fixed braces (train tracks) are designed primarily to straighten teeth. Consequently, to address both Class II problems and crooked teeth may require the use of both a functional appliance, followed by fixed braces or less commonly use of functional and fixed braces together. Alternatives to a functional appliance may include a head brace or extractions; however, the indications for each approach depends on the specific problem.

Will a functional brace change the shape of the face?

Much debate and controversy has surrounded the mode of action of functional braces. It appears that functional braces primarily tip teeth, moving top teeth backwards and lower teeth forwards. Reliable research suggests that the position and length of the lower jaw is governed by our genetic make-up. Therefore, while growth of the lower jaw may be altered in the short-term by a functional brace, it appears that in the long-term no significant difference in jaw position is likely to occur. Nevertheless, by virtue of moving the teeth, changes in lip position may occur with the upper lip covering the top teeth more fully.