Herbst appliance treatment of Class II, division 2 malocclusions.

The purpose of this investigation was to analyze quantitatively the sagittal skeletal and dental changes that contribute to occlusal correction in Herbst treatment of 14 Class II, Division 2 malocclusions. Forty Class II, Division 1 Herbst subjects were used for comparison. Lateral head films from before and after Herbst treatment were analyzed, according to the method of Pancherz. The results revealed that all patients were treated to Class I or overcorrected Class I molar and edge-to-edge incisor relationships. The maxillary and mandibular skeletal changes were similar in both examination groups. In the Class II, Division 2 subjects, sagittal molar and overjet corrections amounted to an average of 5.9 mm and 3.1 mm, respectively. When comparing the Class II, Division 2 with the Class II, Division 1 subjects, overjet correction was, for natural reasons, significantly larger (p < 0.001) in the Class II, Division 1 subjects. In the subjects with Class II, Division 2 malocclusions, the upper incisors were proclined (mean = 3.0 mm), whereas in the subjects with Class II, Division 1 malocclusions, the incisors were retroclined (mean = 2.3 mm). The lower incisors were on the average proclined more (p < 0.05) in the Class II, Division 2 subjects (mean = 3.4 mm) than in the Class II, Division 1 subjects (mean = 2.4 mm). For sagittal molar correction, no differences in tooth movements were seen between the two malocclusions groups. In conclusion, it was found that the Herbst appliance is most effective in the therapy of Class II, Division 2 malocclusions. Proclination of the lower incisors during treatment (anchorage loss) is advantageous in this type of malocclusion.