Tensor analytical evaluation of the effects of a skeletonized activator in the treatment of Class II, Division 1...

The study covered 40 patients (21 boys and 19 girls) whose Class II, Division 1 malocclusion was being treated with a Klammt open activator. To illustrate growth changes, tensor analysis was used as a superimposition-free comparative technique. At the beginning of treatment for Class II correction, the boys had a mean age of 11.3 years and the girls a mean age of 10.1 years. Patients were evaluated on admission and on attaining normal occlusion. 58 boys and 63 girls participating in a growth study at Kings College School of Medicine and Dentistry, London, served as controls.

Prior to treatment the participants suffering from Class II, Division 1 malocclusion exhibited distinct growth deficits in vertical direction. In the control group, the principal direction of mean growth was found to be anterior-inferior. Under the influence of the activator, growth was found to develop in the same direction as in the controls, so that anterior positioning of the lower jaw and an increase in lower facial height were attained.