The unguided functional movement of the human jaw (Charles Gibbs, Ph.D. Harry Lundeen, D.D.S.), DVD.
The most comprehensive study of human chewing mechanics began in 1964 at the Case Western Reserve University in Cleveland, Ohio, with the development of the “Gnathic Replicator“ or ”Chewing Machine”.
This machine could digitally and linearly detect all degrees of the chewing movement with 6 photoelectric measuring sensors. Six stepping motors in the identical geometrical alignment moved jaw models in the same way as the patient moved his lower jaw. For the first time, an intensive study of the chewing movement at all positions of the mandible was made possible!
This project, under the direction of Dr. Charles Gibbs, was later moved to the University of Florida and was pursued until 1983. During this time, huge databanks were collected and interpreted. The possibilities and constraints of the replication of the functional movements in an articulator were also evaluated.
This video summarizes the most important results, bringing to light the recent controversial issues in gnathology dealing with excentric and centric, functional chewing surface composition in the laterotrusion, mediotrusion, protrusion, etc., the roll of the canine, work and balancing movements, the immediate and intermediate sideshift, and lastly the question of the viability of the assumption of a static hinge axis.
