An examination of treatment changes in children treated with the function regulator of Fränkel.

Two groups of patients, one with a Class II, Division 1 malocclusion and the other with a Class III malocclusion, were treated with the Fränkel appliance. Lateral cephalometric radiographs were taken before and after correction of the arch relationship. An examination of the head films with the use of a digitizer and a computer suggests strongly that the principal changes produced by the appliance are dentoalveolar. The need for a randomized controlled clinical trial is emphasized.