To provide information on the current knowledge on the effects of functional appliances using evidence derived from a Cochrane systematic review

To provide information on the way forwards for research into the effects of functional appliances.

It is well established that "functional" orthodontic appliances are very effective in the correction of Class II incisor relationships. Surprisingly, there is still controversy on the method of action of these appliances. This arises from reliance on "evidence" derived from poorly controlled retrospective investigations based around convenience samples of records. In this lecture, I will critically evaluate research into this type of appliance for both "early" and"late" treatment, and discuss the way forwards so that we can understand the true value of this type of treatment.