01 The Functional Regulator according to Fraenkel

The Functional Regulator according to Fraenkel (whether FR-1, FR-2 or FR-3) is an orthodontic appliance that realizes functional orthopedics according to Roux within the orofacial range. It is a predominantly tissue born appliance. That means – in contrast to tooth-borne appliances – the Functional Regulator according to Fraenkel uses the vestibulum as an apparative basis.

Mode of action

The Functional Regulator according to Fraenkel is primarily concerned with the correction of false postures and digressive tonic functional patterns that are closely related to the present dysgnathia.
Funktionsregler nach Fränkel Typ FR3
The Functional Regulator according to Fraenkel Type FR-3


A reduced circumoral soft tissue capsule can affect the displacement of the upper and lower jaw restrictively. The enlargement of the surrounding structures caused by the buccal shields and the lip pads is supposed to eliminate the structural and functional restrictions and to create the requirements for the physiological growth development of the jaws.

The Functional Regulator according to Fraenkel follows the concept of “forced gymnastics”. That means it is an exercise appliance which forces the subconscious to learn new functional patterns after insertion. In addition it is supposed to have a physiotherapeutic effect caused by a structural change of the soft tissue capsule as defined by distension and extension.