Herbst treatment of Class II division 1 malocclusions in retrognathic and prognathic facial types.
OBJECTIVE
The aim of this retrospective pilot study was to analyze and compare the short-term and long-term changes of Herbst treatment in Class II division 1 subjects of the retrognathic and prognathic facial type.


METHODS
The subject material comprised 10 retrognathic (mean SNA = 74.5 degrees, SNB = 70.4 degrees, ML/NSL = 41.1 degrees) and 16 prognathic (mean SNA = 86.7 degrees, SNB = 81.5 degrees, ML/NSL = 25.1 degrees) Class II division 1 subjects treated with the Herbst appliance for an average period of 7 months. Lateral head films from before (T1), immediately after (T2), 12 months after (T3), and 39 months after (T4) Herbst treatment were analyzed with the SO-analysis (analysis of changes in sagittal occlusion) and standard cephalometrics.


RESULTS
During the treatment period (T2-T1) the two facial type groups showed similar favorable changes for all variables. During the posttreatment periods of 12 months (T3-T2) and 39 months (T4-T2) recovering changes occurred. In the long-term, a tendency of more unfavorable growth changes was stronger (not significant) for retrognathic subjects than for prognathic subjects.


CONCLUSIONS
On a long-term basis, retrognathic subjects are prone to exhibit more unfavorable mandibular growth changes than prognathic subjects and, thus, might exhibit a greater risk for an occlusal relapse when a stable Class I occlusion is not attained after treatment.
Bock
Niko
N
Department of Orthodontics, University of Giessen, Giessen, Germany. niko.c.bock@dentist.med.uni-giessen.de
Pancherz
Hans
H
D000293:Adolescent; D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible / Q000254:growth & development; D017289:Orthodontic Appliances, Functional; D009971:Orthodontics, Corrective / Q000295:instrumentation*; D010865:Pilot Projects; D011378:Prognathism / Q000503:physiopathology*; D012008:Recurrence; D063173:Retrognathia / Q000503:physiopathology*; D012189:Retrospective Studies; D016896:Treatment Outcome