[Mathematical investigations of the functional tooth axis].

The functional tooth axis is--contrary of the anatomical tooth axis--defined as follows: The effect of force in its direction causes a maximum of desmodontal fibres being stressed on drawing. After measure of an upper caninus, an upper and a lower molar mathematical models of the teeth and the desmodont of force are calculated with a computer simulation. A variety of functional tooth axes which are not identical with the anatomical ones, result for each tooth. The possible functional axes yield a variety which signifies the biological tolerance. This tolerance causes that many individual forms of occlusion don't have any pathological effect on the desmodont.