Functional Orthodontics

Functional Orthodontics describes the treatment with Activator-like appliances. It was originally introduced by Viggo Andresen in 1935. Since then, a perplexing number of activator-clones have appeared including the Bionator, the Bite-Former, the Kinetor and the Functional Regulator, amongst others. Apart from Andresen the Austrian Karl Häupl was very much engaged in Functional Orthodontics. Both authors created the Andresen-Häupl-Hypothesis which has been dominating orthodontics in Germany and some other European countries for decades.

The fervent advocates of Functional Orthodontics believed that they had discovered a new, “biological” and “causal effective” working principle in orthodontics which they contrasted to the mechanical principle of traditional appliances. They believed that large-volume twin appliances like the Activator could influence the chewing muscle function as well as the mimic muscles. The improved muscle function would lead to the correction of tooth or jaw misalignments in a “natural” way. First of all,  this was only a non-proved scientific hypothesis.

It is not by chance that in the 1930s Functional Orthodontics prevailed over the traditional orthodontics in Germany.  The National Socialists wanted to create a “New German Medicine” based on the principles of alternative medicine and some scientific set pieces. Functional Orthodontics fitted well into this concept: it prevailed over the traditional orthodontics with its mechanical principle and promised the awakening of holistic ideas. In the language of this time, the inventor of the Activator, Viggo Andresen, called for the extermination of traditional “orthodontics”.

The Triumphant Progress of  Functional Orthodontics in Germany

His claim was successful: In the following years, lectures about efficient fixed appliances receded at German universities. In the 1940s at the University of Frankfurt, all active appliances were forbidden ­- even Coffin springs for jaw expansion – because they believed that the Activator and some magical forces would lead to excellent orthodontic results. German orthodontists must have been absolutely desolated: they weren’t able to treat the tiniest misalignments properly. In Nazi-Germany orthodontics had got on a sectarian and unworldly track and stayed so for decades after. It is even worse that all the myths of Functional Orthodontics continued to have an effect until the 1970s or partly until now. There’s no doubt that functional appliances like the Activator can have treatment effects under optimal circumstances, though most of them are of low impact. Functional orthodontics as a dogmatic system of theories seems to line up with the Lyssenkoism in Soviet Russia and the “Deutsche Physik” (German Physics) in Germany during National Socialism. Therefore, Functional Orthodontics is a politically controlled wrong route to take.

The Facts

Orthodontic treatment is based on correcting tooth and jaw misalignments by using orthodontic appliances which exert forces and moments to teeth. They are more or less efficient. Primarily, the tooth itself is affected and moved through the jaw bone. Nowadays, the Functional Orthodontic hypothesis to correct tooth and jaw misalignments indirectly by influencing the muscle function can be recognized as absurd. Moreover, it’s the same misbelief that removable appliances, made of a lump of plastic, could correct teeth in a biological and holistic way, different from fixed appliances.

Early in the 1950s, the best minds among the European orthodontists didn’t support this idea. In 1960, the Danish expert Arne Björk had already published an article giving a well reflected and rejecting statement about Functional Orthodontics. Nowadays, it has been scientifically established that Functional Orthodontics is neither able to influence muscle function nor cranial or jaw growth significantly.

Therefor, the term Functional Orthodontics has become insubstantial and shouldn’t be used anymore.

Why is it Called Dentofacial Orthopedics?

Up to the 1930s, our specialty was called orthodontics (the correction of tooth misalignment) in most languages. But in Germany during the 1930s, those who supported Functional Orthodontics replaced it by the term “Dentofacial Orthopedics” (Kieferorthopädie). Back then, those orthodontists believed that their appliances, made of rubber, could influence the cranial and facial growth significantly.

At the beginning of the 1970s, Tom Graber, editor of the American Journal of Orthodontics (AJO) was persuaded to rename the journal into American Journal of Orthodontics and Dentofacial Orthopedics (AJODO). In the light of the present state of knowledge, this false and misleading titling should be changed back. We aren’t dentofacial orthopedists, only humble orthodontists. If dentofacial orthopedists would be able to correct tooth misalignments they would do the public a bigger service than with unsubstantial higher claims.