The integrated Herbst appliance--treatment effects in a group of adolescent males with Class II malocclusions...

In this study, the effect of the integrated Herbst appliance (IHA) was examined in 30 Swedish males (mean age 14.2 +/- 0.96 years) with a Class II malocclusion. An evaluation of hand-wrist radiographs showed that the patients were in the maturation stages MP3-F, MP3-FG, or MP3-G at the start of treatment. The average treatment time with the Herbst mechanics was 0.7 years. Dentoskeletal and soft tissue parameters were analysed on lateral radiographic head films taken at the start and end of the IHA treatment. The pre- and post-Herbst values of a number of skeletal and dental variables in the treatment group were compared with the corresponding values in a group of untreated age-matched males with Class II malocclusions. Differences in the cephalometric measurements pre- and post-Herbst treatment were determined using paired t-tests. In general, the control group exhibited only minor or no changes during the period of observation, whereas treatment with the IHA resulted in statistically significant and favourable changes of the recorded variables. In the IHA patients, ANB angle was reduced on average by 2.1 degrees. However, a skeletal post-normality (ANB = 3.9 degrees) remained even though a Class I dental relationship had been obtained. In comparison with treatment effects achieved with other designs of Herbst appliances, some minor differences in the changes of the variables SNA and ML/NSL were noted in the present study. These differences could probably be attributed to the particular treatment protocol which was applied in the IHA treatments.