Skeletal and dental changes
upper incisors, incisors, proclination
Previous reports on the maxillary restraining effect are controversial; in the present study, there were no statistically significant changes in any of the two variables used to evaluate the maxillary impact for both age groups. The insignificant effect on the maxilla is in agreement with those of previous studiesHowever, other studies reported that Herbst had a significant restraining effect on maxillary growthAccording to the result of the present study, the Herbst IV appliance resulted in significant retroclination of the upper incisors and distalization of the upper molars, which could be the result of the distally directed force of the appliance (headgear effect) on the maxillary arch. This result is in agreement with previous studies that have reported similar findingsSince most Class II patients come from mandibular rather than maxillary originAfter Pancherz reintroduced the Herbst in 1979Forward movement of the lower molars and proclination of the lower incisors were also evident. Weschler and Pancherz