Co-ordinates of jaw movements.

The method of pantography can he used to record tracings representing the pattern of movement of the jaws. Such tracings can be subjected to analysis on a rectangular coordinate system of axes. All tracings appear to be rotations scribed about instantaneously moving axes. Since the tracings are composites of rotations about the x-, y-and z-axes, they cannot be used to fully describe the jaw movements which produce them. Notwithstanding this limitation, pantographic tracings are of value in the clinical demonstration of individual variations which exist in the patterns of jaw movements. [ABSTRACT FROM AUTHOR]