ARTICULATORS,USES AND IMPORTANCE IN

PROSTHODONTICSPRESENTED BY

DR AGHIMIEN OSARONSE A5TH MAY, 2009

OUTLINEDEFINITIONSPRINCIPLE BEHIND USAGEBASIC DESIGNSCLASSIFICATIONSUSESIMPORTANCECONCLUSION

DEFINITIONS

ARTICULATOR IS A MECHANICAL DEVICE THAT SIMULATE THE TMJ AND ITS JAW MEMBERS TO WHICH THE MAXILLARY AND MANDIBULAR CASTS ARE ATTACHED TO SIMULATE THE JAW MOVEMENT

PRINCIPLE BEHIND USAGE

IT HELPS TO REPLICATE THE POSTERIOR DETERMINANT OF MANDIBULAR MOVEMENT [TMJ] .

OTHER DETERMINANTS INCLUDE;1.ANTERIOR DETERMINANT;THE ANTERIOR

MAXILLARY AND MANDIBULAR TEETH2.NEUROMUSCULAR DETERMINANT ; MUSCLES

AND THEIR NERVE SUPPLY AND LIGAMENT. THE OUTER LIMITS OF ALL EXCURSIVE

MANDIBULAR MOVEMENT ARE CALLED BORDER MOVEMENTS,THE MORE THIS CAN BE REPLICATED BY THE ARTICULATOR, THE MORE IT SIMULATES THE TMJ.

BASIC DESIGNS1. ARCON ARTICULATORS: CONDYLAR ELEMENTS ARE ON THE LOWER MEMBER

OF THE ARTICULATOR,JUST AS THE CONDYLES ARE LOCATED ON THE MANDIBLE.THE MECHANICAL FOSSAE ARE PLACED ON THE UPPER MEMBER AS THE GLENOID FOSSAE ARE IN THE SKULL

.2. NONARCON ARTICULATORS: THE CONDYLAR PATH SIMULATING THE GLENOID

FOSSAE ARE PLACED ON THE LOWER MEMBER WHILE THE CONDYLAR ELEMENTS ARE PLACED ON THE UPPER PORTION.

• THE ARCON TYPES ARE MORE ACCURATE AND ARE EASILY DISASSEMBLED.

• THE NONARCON TYPE IS MORE POPULAR FOR DENTURE FABRICATION

CLASSIFICATIONS

1. NON-ADJUSTABLE 2. ADJUSTBLE .SEMI .FULLY

NON-ADJUSTABLE.

• -DISTANCE B/W THE TEETH AND AXIS OF ROTATION IS SHORTER THAN THAT OF THE SKULL, HENCE LOSS OF ACCURACY

• Does not produce functional movements.

• Accepts a single inter occlusal record.

• Vertical motion may or may not be possible.

• Example: Gariots articulator

• Barn door

• Used for prosthetic and some advanced restorative procedures.

• Holds the cast in a prescribed relationship usually the inter cuspal position [ICP].

• Allows separation and approximation of the cast.

• IT UNDERGOES A SIMPLE HINGE AXIS MOVEMENT

SIMPLE HINGE ARTICULATOR

Fast- Clip Articulator (Partial Protheses and Bridges)

Spring Articulator (Occludator with spring joint)

SEMI-ADJUSTABLE-ALLOWS CLOSE APPROXIMATION OF ANATOMICAL

DISTANCE BETWEEN AXIS OF ROTATION AND THE TEETH

- IT REPRODUCES THE DIRECTION AND END POINT BUT NOT THE INTERMEDIATE TRACK OF SOME CONDYLAR MOVEMENT e.g CONDYLAR INCLINATION ANGLE AND THE BENNETT MOVEMENT..the bodily shift of the mandible to the working side.

- -RECENT SEMI-ADJ ACCOMODATE THE IMMEDIATE LATERAL TRANSLATIONAL

SEMI-ADJUSTABLE CON’T• - THE INTER-CONDYLAR DISTANCES ARE NOT FULLY ADJUSTABLE; COULD BE

SMALL, MEDIUM, OR LARGE.

• Accepts face bow transfer.

• Inter occlusal records can be used to record condyle angle.

• Designs: Arcon type (Mandibular condyle)

• BioArt, Whipmix and Denar series have a condylar element on the lower member which is able to slide against an adjustable plane on the maxillary component.

• Non Arcon type e.g. Dentatus, HanauH2

FOR FABRICATION OF MOST SIMPLE PARTIAL DENTURES AND FIXED PARTIAL DENTURES

Balance Non-Arcon-Articulator

FULLY ADJUSTABLE

• MORE ACCURATE• REPRODUCE THE ENTIRE CHARACTERISTICS OF

THE BORDER MOVT; immediate and progressive lateral translation AND the curvature and direction of condylar inclination.

• Inter-condylar distance is completely adjustable

FULLY ADJUSTABLE con’t• IS EXPENSIVE • REQUIRE HIGH DEGREE OF SKILL• IS TIME CONSUMING.• FOR THIS REASONS IT IS USED PRIMARILY FOR EXTENSIVE

TRT REQUIRING RECONSTRUCTION OF THE ENTIRE OCCLUSION.

• THE PANTOGRAPHIC RECORDING IS USED TO TRACE THE CONDYLAR PATH,THIS WOULD INCLUDE THE RETRUDED, FORWARD, AND MOST LATERAL POSITIONS.

• • Normally of the arcon design e.g Denar series.

Balance De-Luxe with fully adjustable condylar angulation

USES

• Primary function is to act as the patient in his absence

• - Used to simulate the patient’s TMJ, muscles of mastication, mandibular ligaments, mandible and maxilla, the complex neuromuscular mechanism that programs mandibular movement

• - Articulators can simulate but cannot duplicate, all possible mandibular movements even the most sophisticated instrument

• - Instrument can be programmed with certain patient’s records that allow for fabrication of restoration.

USES CON’T

• Mounting dental casts for

– diagnosis,

– treatment plan,

– Representig patient presentation.

• Fabrication of occlusal surfaces for dental restoration.

• Arrangement of artificial teeth for complete and removable

partial dentures.

IMPORTANCE• 1. Patient’s occlusion better visualized from lingual

view• 2. Proper occlusal scheme is better developed

when articulating teeth for complete denture due to lingual view provided by articulator

• 3. Patient cooperation is not a factor to contend with provided appropriate interocclusal records are obtained from patient.

• 4. Refinement of complete denture occlusion in the mouth is difficult because of shifting denture base and resiliency of the supporting tissue.

IMPORTANCE N CON’T

• 5.More procedures can be delegated to auxiliary personnel when utilizing an articulator for development and refinement of the patients occlusion

• 6. Saliva, tongue and cheeks are not considered when using articulator.

• 7. Decreased chair side time.

CONCLUSIONS

IT IS OBVIOUS THAT THE IMPORTANCE OF ARTICULATORS CAN NOT BE OVER EMPHASISED BASE ON THE USES AND FUNCTIONS.IT IS THEREFORE ADVICE THAT PROSTHODONTICS AND OTHER DENTAL PRACTIONEER TO USE ARTICULATORS WHEN FABRICATING PROSTHESES FOR THEIR PATIENTS

•

• THANKS FOR LISTENING