Herbst Treatment of Class II division 1 Malocclusions in Retrognathic and Prognathic Facial Types

Abstract

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.Materials and Methods: The subject material comprised 10 retrognathic (mean SNA = 74.5°, SNB = 70.4°, ML/NSL = 41.1°) and 16 prognathic (mean SNA = 86.7°, SNB = 81.5°, ML/NSL = 25.1°) 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.Conclusion: 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.