Pantographic evaluation of cephalometric hinge axis.

Some commercial positioner manufactures supply clear acetate prescription forms for ordering hinge axis-oriented tooth positioners. These prescription froms assume that the patient's hinge axis is located in the "center of the condylar head." The author, suspecting that this generality could not be axiomatic, investigated fifteen persons, using pantographic hinge-axis-locating equipment, and compared the actual "tatto hinge axis" with the center of condyle as seen on lateral cephalograms. According to pantographic findings, there is a greater than 50 percent chance that the terminal hinge axis is located below and behind the cephalometric "center of the condyle."