Dentofacial changes in patients with Class III malocclusions treated by a combination of activator and chin-cup appliances.

The purpose of this study was to examine, on pre-treatment and post-treatment lateral cephalograms, the effects of combined activator/chin-cup therapy on Class III patients, and to compare mean cephalometric differences noted during treatment with untreated Class I subjects. Fourteen females and fifteen males who exhibited a Class III malocclusion were the subjects of the study. Direct comparison of the mean value changes of the cephalometric variables during treatment of Class III patients with untreated Class I subjects revealed that SNA increased more and SNB increased less in the Class III patients than in the control group, thus improving the ANB angle. At the end of treatment, all patients had a positive overjet but a more concave profile. In this study, combined activator/chin-cup therapy seemed to induce improvement in those Class III patients selected for their moderate condition and treated over a five-year period. The changes seemed to indicate growth patterns which imitate those of the untreated Class I subjects. Moreover, dentoalveolar compensations helped to improve the overjet and conceal skeletal deviations.