Treatment begin and treatment effect in functional orthodontics with jumping-the-bite appliances.
OBJECTIVE
The aim of the present study was to investigate the effects of treatment begin in the early and in the late mixed dentition on treatment with jumping-the-bite appliances.


METHODS
Casts and lateral cephalograms of 69 patients with Angle Class II, Division 1 malocclusions treated with jumping-the-bite appliances were evaluated.


RESULTS
A treatment begin in the early or late mixed dentition resulted in a highly significant reduction in overjet and overbite (p < 0.001), in [symbol: see text] SNA and in [symbol: see text] ANB (p < 0.001). An increase of [symbol: see text] SNB depended upon early (p < 0.001) and late (p < 0.01) treatment begin. In the vertical dimension, an early treatment start induced a slightly significant increase in [symbol: see text] NL/NSL and highly significant changes in the upper and lower incisors. With a late treatment start, these changes applied only to the lower incisors. The changes differed significantly only with respect to incisor inclination (upper arch p < 0.01, lower arch p < 0.05). The later the treatment start, the less significant were the dentoalveolar effects.


CONCLUSIONS
At the end of the study period, a slightly significant intergroup difference was recorded for lower incisor inclination only.
Lisson
Jörg A
JA
Department of Orthodontics, University of Saarland. zkojlis@uniklinik-saarland.de
Tränkmann
Joachim
J
D000293:Adolescent; D000367:Age Factors; D002508:Cephalometry / Q000706:statistics & numerical data; D002648:Child; D003818:Dentition, Mixed; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008432:Mathematical Computing; D017289:Orthodontic Appliances, Functional; D012189:Retrospective Studies; D016896:Treatment Outcome