Predicting functional appliance treatment outcome in Class II malocclusions--a review.

Selecting cases suitable for treatment with a functional appliance remains a problem as much of the relevant literature is anecdotal. There are also design and methodologic differences between the available studies, and most studies are limited to the Andresen type of appliance. The literature suggests that functional appliances are most successful in cases with an overjet of up to 11 mm, an increased overbite, active facial growth, and good cooperation.