VECTORIAL ANALYSIS OF THE EQUILIBRIUM OF FORCES TRANSMITTED TO TMJ AND OCCLUSAL BITEPLANE SPLINTS

A mechanical model (link quadrilateral bell crank) is used to demonstr ate the equilibrium of normal force vectors transmitted to the mastica tory system and maxillary occlusal biteplane splints with different de signs. Occlusal contacts were imposed on the proposed models under the action of a masticatory force vector with an arbitrary value of 40 kg f. The consequence of this force action created different responses wi thin the joint and at the level of the dentition. When compared to the intercuspal position in centric occlusion, intra-oral appliances with either smooth contacting surfaces or indentations, both with increase d vertical dimension, forced the mandible to assume an anterior positi on with a concurrent increase of joint forces. The bite-splint that pr oduced the least amount of joint force was the stabilization type with minimal increase of vertical dimension.