Various removable and fixed orthodontic appliances were rated by interview and questionnaire by 42 myofunctional therapists in the Hamburg area with respect to their influence during myofunctional therapy. The Nance holding arch was given the most negative rating of all appliances covering the palate area. For the active plate, marking the rest position of the tongue by roughening the acrylic surface or by reproducing the palatal relief was considered beneficial. The quadhelix expansion device and Hyrax palatal expander were rated as unfavorable because of their positioning in the palatal area. Among the functional appliances, Fränkel's function regulator was given the best rating. Regular fixed appliances (brackets, bands) were not considered a disturbance. Habit reminders (plates and spurs) were given a very negative rating by ca. 80% of the therapists because they disturbed the myofunctional exercises and led to adaptive dysfunctions. Since many patients with dysfunction of the orofacial musculature undergo simultaneous myofunctional and orthodontic therapy, treatment planning and choice of orthodontic appliances should be carefully coordinated.
