THE ARTICULATORTHE ARTICULATOR

• The articulator is a mechanical instrument designed to simulate the movements of the mandibular arch in relation to the maxillary arch.

• These movements are directed and limited by the elements of the articulator that simulates the anatomical determinant of mandibular movement.

Adjustablility of the articulatorAdjustablility of the articulator

• The capability of the articulator to closely simulate the movements of the mandible is dependent upon the ajustability of the articulator elements

ELEMENTS OF AN ARTICULATORELEMENTS OF AN ARTICULATOR I. I.• Horizontal axis of rotation:-- Variability of the

position of the horizontal axis of rotation in relationship to the maxillary dental cast.

• Condylar inclination/fossa components: -- Variability of the angle of the eminentia, directional guidance of the superior, posterior, and medial walls of the fossa, and ability to simulate laterotrusive movement.

• Inter Condylar distance: -- Adjustability of the distance between the vertical axes of rotation.

• Bennett angle/Bennett movement:--Adjustability of the angle and capability of simulating sideshift movement.

• Incisal guidance:--Adjustability and ability to simulate the anterior guidance of the natural dentition.

ELEMENTS OF AN ELEMENTS OF AN ARTICULATORARTICULATOR II. II.

• All elements are dependent and variable with the type of articulator.

• Articulators of various designs may incorporate all or none of the elements dependent on their intended use and necessity to fully simulate mandibular dynamics.

• These designs vary from the simple hinge-like articulator to the more elaborate instruments capable of closely simulating mandibular movement.

ELEMENTS OF AN ELEMENTS OF AN ARTICULATORARTICULATOR III. III.

TYPES OF ARTICULATORS: TYPES OF ARTICULATORS: NON-ADJUSTABLENON-ADJUSTABLE

• CLASS I: SIMPLE HINGE

• The movement of these articulators is limited to inaccurate hinge opening and closing arcs about a fixed axis. the maximum intercuspatiion position is the only position that can be reproduced. Casts are arbitrarily mounted without use of a facebow.

Grittmann 1899Grittmann 1899

Hall 1924Hall 1924

Hays 1860Hays 1860

Kerr 1919.Kerr 1919.

• CLASS II: ARBITRARY VALUE (PLANE LINE)

• Evolved from the Class I articulator design, these

articulators are capable of lateral movement. Some are

capable of variable location of the horizontal axis of

rotation (they are full size and capable of accepting a

facebow), but all of this type have fixed, arbitrary condylar

inclination settings, vertical axes of rotation settings, and

Bennett Angle. No adjustment of these posterior elements

is available. Some have a provision for incisal guidance.

TYPES OF ARTICULATORS: TYPES OF ARTICULATORS: NON-ADJUSTABLENON-ADJUSTABLE

Monson 1908.Monson 1908.

TYPES OF ARTICULATORS: TYPES OF ARTICULATORS: ADJUSTABLEADJUSTABLE

• CLASS III: SEMI-ADJUSTABLE CLASS III: SEMI-ADJUSTABLE • These articulators can simulate lateral, protrusive

and Bennett movements to varying degrees. The amount of adjustability incorporated in the design provides the degree of simulation available.

• By utilizing a facebow and intraoral maxillo-mandibular records, these articulators can be programmed to simulate the curvilinear anatomical movements with a beginning and ending point border movement resulting in a straight line simulation. For this reason, these instruments are often called straight line articulatorsstraight line articulators.

SEMI-ADJUSTABLE SEMI-ADJUSTABLE

• This class of articulators is suited for partial and complete removable protheses, individual crowns, short span bridges, and selected quadrant restorations.

• However the lack of accurate simulation of lateral and protrusive movements (straight line) requires final refinement intraorally.

Types of semiadjustable Types of semiadjustable articulatorsarticulators

• ARCON:ARCON:

• There are essentially two designs of semi-adjustable articulators. One which has the guidance of condylar movement in the maxillary member and the centers of axial rotation in the mandibular member. This design is termed ARCON (ARticulating-CONdyle) articulators.

• NONARCON:NONARCON:

• The non-arcon articulator design has these elements reversed.

Kinescope 1921.Kinescope 1921.

DENAR 1968.DENAR 1968.

• CLASS IV: FULLY ADJUSTABLE

• This class of articulators accepts registration of all anatomic determinant of occlusal morphology, and most closely simulates the movement directed by these controls. The posterior elements of these controls are directed and adjusted by an extra-oral technique called a pantographic registration. This class will accept a "hinge axis" kinematic transfer bow. The incisal guidance can closely simulate the paths of the natural dentition.

• This class is fully utilized in extensive restorative procedures, as well as adjunct to diagnostic determinations of temporomandibular joint dysfunction (TMJ).

TYPES OF ARTICULATORS: TYPES OF ARTICULATORS: ADJUSTABLEADJUSTABLE

Facilities by the PROTAR 9Facilities by the PROTAR 9

THE FACEBOWTHE FACEBOW

• PURPOSE:

• The function of the facebow is to record the

relationship of the maxillary arch to the

horizontal axis of rotation of the mandible

(sometimes referred to as the terminal hinge

axis).

• Three points of reference are necessary to order to Three points of reference are necessary to order to

designate a plane. The points needed in order to utilize designate a plane. The points needed in order to utilize

a face tow are:a face tow are:

• 1 &2 -- The two skin points that describe the exact or

abbitary points where the horizontal axis passes through

the skin serve to designate two of the points of the plane of

orientation of the facebow.

• When an earpiece facebow is used, the two points where

the ear rods of the facebow enter the external auditory

meatus of the ear serve as the two points of orientation.

THE FACEBOWTHE FACEBOW

• 3--the third point of reference is located on the face at a point that will assist the convenient location of the maxillary cast between the upper and lower members of the articulator.

• This point of reference may vary depending on which brand of articulator is used.

• Having completed the facebow registration, the maxillary cast can be mounted in the articulator in relationship to the condylar mechanism and the horizontal plane of reference.

THE FACEBOWTHE FACEBOW

TYPES OF FACEBOWSTYPES OF FACEBOWS

• 1. Simple facebow (arbitrary or earpiece)

• 2. Hinge axis transfer bow (kinematic)

1. Simple facebow (arbitrary or 1. Simple facebow (arbitrary or earpiece)earpiece)

• The simple facebow can be utilized to transfer the

relationship of the maxillary arch and an average

intercondylar axis. The axis can be designated either

arbitrarily (average measurement along the Frankfort

Horizontal Plane) or by the position of the ear rod in the

ear canal.

• The difference in the position of the ear bow position is

accommodated for by the design of the articulator and its

earbow receiver points.

2. Hinge axis transfer bow 2. Hinge axis transfer bow (kinematic) (kinematic)

• A more precise location of the horizontal axis can be made with a kinematic registration of this axis using a kinematic registration bow.

• The exact location of the points where the axis passes through the skin is a time consuming clinical endeavor requiring special instrumentation.

• The precise location of the horizontal axis of rotation is demanded by the techniqus necessary to do extensive restorative procedures.

• Variations betweeen the point location of the arbitary and hinge axes has been demonstrated as sources of error in the fabrication of extensive dental restorations.

Kinematic face bow:Kinematic face bow:Biting fork is attached to the lower Biting fork is attached to the lower

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