[New electronic-mathematical method for measuring the condylar center of rotation].

Abstract

Until today, not all methodical details and problems concerning the exact and reproducible determination of the condylar hinge axis have been solved yet. All familiar mechanical-manual and electronically supported methods as well as computer methods of some electronical recording systems have their limitations and are partly incorrect up to now. The reason for this lies mainly in the theoretical respectively mathematical approach towards these methods. With the aim of determining a point of minimal translatory movement ("steady point") during the rotatory opening movement in the TMJ condyle, a mathematical method is presented, which calculates the 3D coordinates of the condylar rotation centers automatically, i.e. without manual manipulation of the recording system. Contrary to conventional methods, this new technique is very precise and relatively less sensitive towards superimposed translatory movements.