Articulators and Their Functions

8/10/2019 Articulators and Their Functions

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RESD 702Introduction to Occlusion



“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.”

Glossory of Prosthodontic Terms, 2005





arcon \ar-kon\ n:

a contraction of the words

„„ARTICULATOR‟‟ and„„CONDYLE,‟‟ used

to describe an articulator containing the

condylar path elements within its upper

member and the condylar elements withinthe lower member



Arcon articulator

an articulator that applies the arcon design;

this instrument maintains anatomic

guidelines by the use of condylar analogs

in the mandibular element and fossae

assemblies within the maxillary element





nonarcon articulator:1: any articulator which broadly replicates the

three dimensional motions of the left and rightcondylar compartments

2: any articulator design in which the condylarelement (analog) is not part of the lowermember of the articulator and may be used to

simulate the three dimensional motions of theleft and right condylar compartments





Non-Adjustable

Semi-Adjustable

Fully-Adjustable



Divided into four classes.



Class I articulator: a simple holdinginstrument capable of accepting a singlestatic registration; vertical motion is possible

Horizontal movement is limited or nonexistent

Also called a “Non- Adjustable Articulator”

“Snake Bite” or “Barn Door Hinge”





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 ormechanical equivalents for all or part of themotion; these instruments allow fororientation of the casts relative to the joints and may be arcon or nonarcon instruments

“Semi-adjustable Articulator”





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 movement

“Fully Adjustable Articulator”













Horizontal axis

An imaginary line passingthrough the bothcondyles



As the mandible pivots on

it‟s “Hinge Axis”, the cusp of

each mandibular tooth

moves along an arc



A simple holding instrument capable ofaccepting a single, static registration

Horizontal motion is limited

Hinge opening is the primary function



The dissimilarity between the

hinge axis of the non-adjustable articulator andthe hinge axis of themandible produces adiscrepancy in the arc ofclosure between thearticulator and the mandible



A MAJORDISCREPANCYEXISTS BETWEEN

THE NON-WORKINGCUSP PATH ON ANON – ADJUSTABLE

ARTICULATOR AND

THAT FOUND IN THEMOUTH



SIMULATES CONDYLAR PATHWAYSBY USING AVERAGES ORMECHANICAL EQUIVELANTS FORALL OR PART OF THE MOTION

ALLOWS FOR ORIENTATION OFTHE CASTS RELATIVE TO THE TMJ

APPROXIMATES PATIENTSMANDIBULAR MOVEMENTS

MAY BE ARCON OR NON –ARCONINSTRUMENTS



THE DISSIMILARITY

BETWEEN THE HINGE AXIS

OF THE SEMI-ADJUSTABLE

ARTICULATOR AND THEMANDIBULAR HINGE AXIS

WILL CAUSE A SLIGHT

DISCREPANCY BETWEEN THE

ARC OF CLOSURES OF THE

ARTICULATOR AND THE

MANDIBLE



THERE IS ONLY A SLIGHTDIFFERENCE BETWEENCUSP PATHS ON A SEMI-

ADJUSTABLE ARTICULATOR ANDTHOSE IN THE MOUTHEVEN THOUGH THE CASTMOUNTING EXHIBITS ASLIGHT DISCREPANCY



THE CONDYLE

TRAVELS A CURVED

PATH IN MANDIBULAR

MOVEMENTS

THIS REPRODUCED IN

SEMI-ADJUSTABLE

ARTICULATORS AS A

STRAIGHT PATH



AN INSTRUMENT THAT WILL ACCEPT THREE

DIMENSIONAL DYNAMIC REGISTRATIONS

THESE INSTRUMENTS ALLOW FORORIENTATION OF THE CAST TO THE TMJ AND

REPLICATION OF ALL MANDIBULAR

MOVEMENTS



ARTICULATOR HINGE AXIS IS EQUAL TO

MANDIBULAR HINGE AXIS

NO DISCREPANCY BETWEEN ARC OF

CLOSURE OF ARTICULATOR AND MANDIBLE CONDYLAR PATHWAYS ARE CURVED AS

THEY ARE FOR THE PATIENT

NO DISCREPANCY IN WAX-UP



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Articulators and Their Functions