articulator

a mechanical instrument that represents the temporomandibular joints and jaws, to which maxillary and mandibular casts may be attached to simulate some or all mandibular movements—usage: articulators are divisible into four classes. Class I articulator: a simple holding instrument capable of accepting a single static registration; vertical motion is possible—see NONADJUSTABLE A. Class II articulator: an instrument that permits horizontal as well as vertical motion but does not orient the motion to the temporomandibular joints. Class III articulator: an instrument that simulates condylar pathways by using averages or mechanical equivalents for all or part of the motion; these instruments allow for orientation of the casts relative to the joints and may be arcon or nonarcon instruments—see SEMI-ADJUSTABLE A. Class IV articulator: an instrument that will accept three dimensional dynamic registrations; these instruments allow for orientation of the casts to the temporomandibular joints and simulation of mandibular movements—see FULLY ADJUSTABLE A., FULLY ADJUSTABLE GNATHOLOGIC A.