[Differential diagnosis of electronic TMJ tracings in dysfunction patients]

Only in a minority of cases do electronic TMJ tracings allow a clear differentiation between arthrogenous dysfunctions. To us, the major application of this recording technique appears to be the diagnosis of dislocations of the articular disk. Because of the great variability of possible dislocation patterns it is mandatory that the interpretation of electronic jaw tracings be standardized to avoid contradictory interpretations and to enhance the validity of this diagnostic tool. In trying to establish reliable, hardware-independent criteria for the evaluation of joint tracings in TMJ dysfunctions, it is the shape of the condylar inclination, the time-correlation of condylar path changes in all three planes and the direction of these changes, that are of utmost diagnostic significance: Repeated recordings of all functional movements are necessary to ensure tracings of high diagnostic value. The diagnostic potential of three-dimensional electronic jaw tracings can be further enhanced by guided jaw movements, e.g. functional compression, which result in characteristic changes of the tracings.