Correction of a skeletal Class II malocclusion with functional appliances h
as been accepted as a viable treatment modality. However, its mechanism of
action is still disputed. This retrospective study compared 20 Class II pat
ients treated with the functional magnetic system (FMS) with Class I and Cl
ass II groups (the control groups) of 20 untreated subjects each. Dental an
d skeletal changes were compared using serial lateral cephalograms. The FMS
group differed significantly from the control groups in 15 of 24 parameter
s. The great,-increase in articulare-gnathion distance (3.07 mm) attributed
to the attractive magnetic component of the FMS dictates a prolonged propu
lsion of the mandible. The skeletal:dental response ratio was 1:2 for the a
nterior region and 1:1 for the posterior region. The dental and skeletal pa
rameters demonstrated a synergistic response in the maxilla and a competiti
ve response in the mandible. This means that greater maxillary molar distal
movement and incisor retroclination resulted in a more significant restrai
nt of point A. In contrast, increasing the mandibular molar mesial movement
and the incisor proclination accompanied less advancement of the pogonion.
Although the skeletal contribution to the resolution of the malocclusion w
as less than the dental contribution (anteriorly, one third), the functiona
l correction response was found to be regulated by skeletal factors.