A group of ten adolescents was treated with fixed appliances at the Department of Stomatology and Oral and Maxillofacial Surgery, Graz. Subsequently the patients were fitted with a gnathological positioner. On the day of band removal ten sets of models were made and subsequently two, four and twelve weeks later. They were mounted on an articulator and cephalometric measurements were taken three times by each of the examiners. These records served to provide evidence of discrepancies of the condylar position between ICP and RCP in all three planes. In the second part of the examination, the patients were instructed to wear the appliance at night for another year. Casting of models, mounting in articulators and condymetric measurements were repeated as above. After wearing the positioner for three months, we observed a definite improvement of the occlusion and a wide conformity of the RCP and ICP measurements. After one year of night-time retention there was a slight increase of the mean values. In addition, we could establish statistically that condymetric model measurements are independent of the examiner and the method employed.