Functional Appliances
In the mid 1800s dentists started to think about the effect of facial muscles on the position and movement of the jaw bones. In 1879 Norman Kingsley was the first to design an appliance to stimulate jaw growth. In 1902 Pierre Robin introduced the first functional appliance called the mono bloc. It was the first appliance to reposition the jaw and was used to treat patients with glossoptosis syndrome.
The first widely used functional appliance was Vigo Andresen’s activator. He developed the appliance to treat his daughter’s class II malocclusion. Later Andresen worked with Karl Häupl to develop the Norweigan system of functional jaw orthopaedics. Andresen’s appliance would go on to be modified by others, producing new types of appliance.
All Functional Appliances
Monobloc
The mono bloc was the first functional appliance. It was first used by Pierre Robin in 1902 to treat patients with glossoptosis syndrome.
Harvold activator
The Harvold Activator was developed by Egil Peter Harvold, a Norweigan dentist who later moved to America and was largely responsible for the introduction of functional appliance therapy to the country. The activator is constructed to a widely open bite to gain maximum effect from the movement of the muscles.
Clark’s twin block
The twin block was developed by William Clark for the treatment of Class II malocclusions. It was based on the same theory as the monobloc and Frankel appliance. The appliance consists of maxillary and mandibular bite blocks designed to use the forces of occlusion as the functional mechanism.
Frankel Function Regulator
The function regulator was developed by Rolf Frankel, a German orthodontist, in the 1980s. The appliance is a complex device which uses the oral cavity the basis for treatment of malocclusions with little or no contact with the dentition. Versions of the appliance were available to treat Class I, Class II and Class III malocclusions. The appliance became very popular both in Europe and America.
Andresen activator
In 1909 the Danish dentist Viggo Andresen removed his daughter’s fixed appliance and replaced it with a Hawley retainer, which he had modified with a lower arch wire designed to move the mandible. The appliance worked in correcting Andresen’s daughter’s class II malocclusion, so Andresen began to explore ways to develop his appliance further.
