CT-scanning and radiographic analysis of temporomandibular joints and cephalometric analysis in a case of Herbst treatment in late puberty.

From a consecutive sample of 100 patients treated with the Herbst appliance after the peak of puberal growth, a boy was chosen to show the total effect of the Herbst treatment. Changes in the dentofacial morphology and the structure of the temporomandibular joints (TMJ) were followed by radiologic examinations and the function of the craniomandibular system was studied by clinical examinations, and electromyographic and bite-force recordings. Treatment resulted in marked dentoalveolar changes, an increase of mandibular length, ramus height, and gonion angle. Three months after insertion of the appliance CT-scanning and orthopantomograms of the TMJ revealed new bone formation as a double contour in the fossa articularis and on the posterior part of the condylar process as a result of adaptive bone remodelling. Function was affected by treatment, but was markedly restored at control.