Abstract
Functional orthopaedics fulfills treatment expectations whenever the therapeutic devices are used within the limits of their applications. Especially successful has been the application of modified, skeletalized (reduced) activators in the deciduous and the mixed dentition, and the use of functional appliances in the early permanent dentition in Angle Classes I, II, and III malocclusions where primary functional causes exist. Whilst the inter-arch expansion obtained with functional appliances may average more than 3-4 mm and provide good treatment responses, the single tooth movements, including rotations, are more certainly and more effectively carried out with fixed appliances. In the latter types of cases, combined therapy, consisting of pre-treatment with an active fixed appliance and subsequent treatment with the activator, may be more successful.