American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics vol:92 issue:2 pages:162-8
Several working hypotheses have been conceived to explain the mode of action of various functional appliances. A review of the different concepts is presented and these concepts are tested by means of data from basic scientific research. Furthermore, a general concept is postulated that could unite the working principles of several functional appliances. Finally, the clinical relevance of scientific research in this area is evaluated.