A comparison of skeletal and dental changes produced by function regulators (FR-2 and FR-3).
The lateral skull radiographs of subjects taken before and after treatment with the FR-2 (N = 99) and FR-3 (N = 30) of Fränkel were compared to contrast the effects of each appliance. The major skeletal effect of both appliances was on the mandible, the FR-2 group showing a significantly greater annual increase in total length and ramus height (P less than 0.001) and the FR-3 group a significant change in position downward and backward facilitated by an opening of the cranial base angle. The greater annual increase in lower facial height, compared with a control group, seen in both FR groups was accompanied by a reduction in overbite, which was greater in the FR-2 group. The favourable change in overjet seen in both FR groups was contributed to by alteration in upper and lower incisor inclination.
Kerr
W J
WJ
TenHave
T R
TR
McNamara
J A
JA
D000202:Activator Appliances; D002508:Cephalometry; D002648:Child; D005147:Facial Bones / Q000473:pathology*; D005260:Female; D006801:Humans; D007568:Jaw / Q000473:pathology; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D009968:Orthodontic Appliances, Removable; D014070:Tooth / Q000473:pathology*; D014716:Vertical Dimension