[The bionator with extraoral traction--the Wurzburg concept. 1].

In this publication the bionator with extraoral anterior traction is presented. The preparation of the bionator and the headgear fit is demonstrated. The indication for the use of the appliance combination is outlined. The results of a cephalometric study concerning the therapeutic effects are presented. The following changes are especially noteworthy: There is a reduction of the SNA-angle, a significant retrusion of the upper incisors occurs. The mesial drift of the upper 6-year molars is inhibited, a slight posterior rotation of the maxilla is observed. In patients who wore their appliances well, a protrusion of the lower incisors could not be observed.