Articulators1/prosthodontic courses

ARTICULATORS

INDIAN DENTAL ACADEMY Leader in Continuing Dental Education

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DENTAL ARTICULATOR IS AN INSTRUMENT THAT DUPLICATES CERTAIN IMPORTANT DIAGNOSTIC AND BORDER MOVEMENTS OF MANDIBLE

IN THE FABRICATION OF THE INDIRECT PROSTHESES A MECHANICAL DEVICE IS USED TO RELATE THE OPPOSING CASTS SUCH A DEVICE IS CALLED AN ARTICULATOR

GPT-7: IT IS A MECHANICAL DEVICE WHICH REPRESENTS THE TEMPOROMANDIBULAR JOINT AND JAW MEMBERS TO WHICH MAXILLARY AND MANDIBULAR CASTS ARE ATTACHED TO SIMULATE SOME OR ALL OF THE MANDIBULAR MOVEMENTS

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IS AN ARTICULATOR NEEDED ?

PRIMARY PURPOSE OF THE ARTICULATOR IS TO ACT AS A PATIENT IN THE ABSENCE OF THE PATIENT TO PRODUCE BORDER AND INTRABORDER DIAGNOSTIC SLIDING MOTIONS OF THE TEETH SIMILAR TO THOSE IN THE MOUTH

TO MOUNT THE CASTS FOR DIAGNOSIS, TRETMENT PLANNING AND PATIENT PRESENTATION FABRICATION OF THE OCCLUSAL SURFACES FOR DENTAL RESTORATION ARRANGEMENT OF TEETH FOR COMPLETE DENTURE AND PARTIAL DENTURES


CONTENTS HISTORY OF ARTICULATORS CLASSIFICATION OF ARTICULATORS REQUIREMENTS OF ARTICULATORS TYPES OF ARTICULATORS EVOLUTION OF ARTICULATORS LIMITATION OF ARTICULATORS SELECTION OF ARTICULATORS SUMMARY CONCLUSION


HISTORY OF ARTICULATORS PLASTER ARTICULATOR BY PHILLIP. PHAFF IN 1756

IN 1805, GARIOT DESIGNED HINGE JOINT ARTICULATOR. IT CONSISTED OF TWO HINGE JOINT AND SET OF SCREW IN POSTERIOR

IN 1840, CAMERON AND EVANS

DESIGNED PLANE LINE ARTICULATOR


ADAPTABLE BARN DOOR ARTICULATOR IS CAPABLE OF OPENING AND CLOSING ONLY.IT HAD AN ANTERIOR VERTICAL STOP WHICH WAS CARRIAGE OR MACHINE BOLT

IN 1858, BONWILL DEVELOPED AN ARTICULATOR BASED ON HIS THEORY OF OCCLUSION

IN 1906 GEORGE.B.SNOW DEVELOPED NEW CENTURY ARTICULATOR IT WAS BASICALLY GRITTMAN INSTRUMENT TO WHICH ADJUSTABLE CONDYLAR PATH AND TENSION SPRING WERE ADDED


IN 1920 SECOND CONGRESS OF THE NATIONAL SOCIETY OF DENTURE PROSTHODONTICS WAS ORGANISED IN BOSTON

MAIN AIM OF THE CONGRESS WAS TO HAVE A UNIVERSAL ARTICULATOR WHICH COULD BE USED BY ALL

IT WAS A RESOUNDING FAILURE AS THE CONGRESS WAS DIVIDED BY TWO SCHOOLS OF THOUGHT

ONE WAS HEADED BY RUPERT. HALL OF HOUSTON …..RUPERT. HALL OF HOUSTON …..

THE OTHER WAS HEADED BY ALFRED. GYSI OF ZURICH…ALFRED. GYSI OF ZURICH…


STATE OF KNOWLEDGE BEFORE THE CONGRESSIN 1890 ANATOMIST GRAF SPEE OF BERLIN FOLLOWED THE ANTEROPOSTERIOR CURVE OF MANDIBULAR TEETH THAT BEARS HIS NAME

IN 1896, W.E.WALKER SAID THAT THE DENTURES WHICH WERE BALANCED IN BONWIIL ARTICULATOR DID NOT BALANCE IN THE MOUTH ….HE DEVISED CLINOMETER WHICH HAD PROVISION TO RECORD MOVEMENTS OF MANDIBLE

IN 1896,N.G. BENNETT HELPED BY HIS BROTHER, RECORDED THE MOVEMENT OF THE CONDYLE ,USING A FACIAL ARC CARRYING A SMALL PROJECTOR


IN 1866, F.H. BALKWILL HAD ALREADY RECORDED THIS DISPLACEMENT AND HENCE IT WOULD THUS BE RIGHT TO CALL IT “ANGLE OF BALKWILL- BENNETT”

DURING THIS SAME YEAR 1866, F.H. BALKWILL HAD CHARACTERIZED THE MANDIBULAR DENTAL ARCH BY AN EQUILATERAL TRIANGLE THAT W.G.A. BONWILL EXTENDED IN 1899 TO THE WHOLE OF THE MANDIBLE.

THIS LAST DESCRIPTION IS FOUND IN THE THEORY OF THE SPHERE WHICH WAS DEVELOPED BY GEORGE S. MONSON DURING THE SAME YEAR AND WHICH GOVERNS THE DEVELOPMENT, IN 1923, OF A CORRESPONDING ARTICULATOR www.indiandentalacademy.comwww.indiandentalacademy.com

RUPERT. HALL AND HIS GEOMETRIC CONCEPTS RUPERT HALL INITIALLY TRIED TO ASSOCIATE EQUILATERAL TRIANGLE OF BONWILL AND THEORY OF THE SPHERE OF MONSON (1914) AND DEVELOPED A SERIES OF ARTICULATORS CALLED " ALLIGATOR " BECAUSE OF THE PARTICULAR SHAPE OF THE INSTRUMENT (1916-1917)

NOT BEING ABLE COMPLETELY TO REJECT THE MOVEMENT OF BALKWILL-BENNETT, RUPERT HALL ADOPTS AN AXIS OF ROTATION OF MANDIBLE AROUND A POINT LOCATED AT THE MIDPOINT OF THE BASE OF THE TRIANGLE OF BONWILL AND DEVELOPED AN ARTICULATOR CALLED “SIMULATOR”


THE EVOLUTION OF THIS CONCEPT LEAD R. HALL TO HIS DEVELOPMENT IN SPACE BY THE CONSTRUCTION OF TWO PYRAMIDS OPPOSED BY THEIR BASE WHICH THEN LOCATES THE CENTRE OF ROTATION AT THE BASE OF CRANIUM CLOSE TO THE PITUITARY PIT (1918).THIS CONCEPT GAVE RISE TO WHAT IS COMMONLY CALLED THE " THEORY OF THE CONE " .IN 1918, RUPERT HALL DEVELOPED “AUTOMATIC ANATOMICAL ARTICULATOR”


LATER RUPERT HALL WORKING ALONG WITH J.W.NEEDLES AND C.I.STRANSBERRY DEVELOPED “THREE DIMENSIONAL ARTICULATOR” AND “ STRANSBERRY TRIPOD”


ALFRED. GYSI AND HIS GEOMETRIC CONCEPTS GYSI WAS INFLUENCED BY BONWILL TRIANGLE BUT WANTED TO IMPLEMENT EXTRAORAL RECORDING IN HIS ARTICULATOR “ADJUSTABLE”

BETWEEN 1912-13 SEVERAL ARTICULATORS KNOWN AS “ADAPTABLES” WERE FABRICATED ALONG WITH MULLER, SHRODER, RUMPLE AND FISCHER


GYSI’S WORK PAVED WAY FOR GNATHOLOGY. MCCOLLUM A DEVOTED STUDENT OF GNATHOLOGY ALONG WITH WADSWORTH DEVELOPED AN ARTICULATOR THAT HAD ADJUSTABLE INTERCONDYLAR WIDTH

GRANGER DEVELOPED – GNATHOLATOR

STUART DEVELOPED GNATHOLOGIC COMPUTER-IT NOT ONLY RECORDS AND REPEATS THE POSITION IN THREE PLANES IT ALSO RECORDS THE FOURTH DIMENSION -TIME


TRANSOGRAPH (1952) IS A HINGE AXIS FACEBOW THAT CAN BE MODIFIED LATER TO SERVE AS AN ARTICULATOR-- IS A SPLIT AXIS INSTRUMENT. IN THIS ARTICULATOR EACH CONDYLAR AXIS IS INDEPENDENT OF THE OTHER. THE ROTATION AND OPENING MOVEMENTS CAN TAKE PLACE THROUGH TWO DIFFERENT AXES

THE NEY ARTICULATOR (1962)DESIGNED BY ANTHONY J. DEPIETRO IN 1962.THE CONDYLAR ELEMENTS CONTAIN METAL INTER CHANGEABLE CONDYLAR PATHS WHICH CAN BE ADJUSTED IN ALL THREE PLANES TO ACCEPT ALL POSITIONAL RECORDS.

THE TMJ ARTICULATOR(1965)DESIGNED BY KENNETH SWANSON IN 1965. A CUSTOM ANALOG FOSSA FORMED FROM INTRA ORAL STEREOGRAPHIC TRACINGS IS NEEDED A SERIES OF 5 PREMADE FOSSA ANALOGS ARE ALSO AVAILABLE.


CLASSIFICATION OF ARTICULATORS WEINBERG (1963)I. ARBITRARY – MONSON ARTICULATORII . POSITIONAL – STRANSBERRY TRIPOD III. & IV. SEMI ADJUSTABLE AND FULLY ADJUSTABLE – SEMI ADJUSTABLE – FOLLOWED HANAU H CONCEPT FULLY ADJUSTABLE – FOLLOWED HANAU KINOSCOPE CONCEPT

JOHN J. SHARRY (1974) 1. SIMPLE HINGE TYPE2. FIXED GUIDE TYPE3 ADJUSTABLE INSTRUMENTS

BOUCHER(1) THE THEORIES OF OCCLUSION AND(2) THE TYPES OF RECORDS USED FOR THEIR ADJUSTMENT. I. Those utilizing the Inter occlusal records. II. Those using the Graphic record adjustment. III. Those utilizing hinge-axis location for adjusting the articulator.


INTERNATIONAL PROSTHODONTIC WORKSHOP ON COMPLETEDENTURE OCCLUSION AT UNIVERSITY OF MICHIGAN 1972

CLASS I. A SIMPLE HOLDING INSTRUMENT CAPABLE OF ACCEPTING A SINGLE STATIC REGISTRATION. VERTICAL MOTION IS POSSIBLE. EXGariot articulator

CLASS II. AN INSTRUMENT THAT PERMITS HORIZONTAL AS WELL AS VERTICAL MOTION BUT DOES NOT ORIENT THE MOTION TO THE TEMPOROMANDIBULAR JOINTS. SUBDIVISION A: ECCENTRIC MOTION

PERMITTED IS BASED ON AVERAGE OR ARBITRARY VALUES. Ex: Grittman articulator

SUBDIVISION B: ECCENTRIC MOTION PERMITTED IS BASED ON THEORIES OF ARBITRARY MOTION. EX: Monson articulator www.indiandentalacademy.comwww.indiandentalacademy.com

SUBDIVISION C: ECCENTRIC MOTION PERMITTED IS DETERMINED BY THE PATIENT USING ENGRAVING METHODS. EXAMPLES: The House Articulator

CLASS III. AN INSTRUMENT THAT SIMULATES CONDYLAR PATHWAYS BY USING AVERAGES OR MECHANICAL EQUIVALENTS FOR ALL OR PART OF THE MOTION SUBDIVISION A: INSTRUMENTS THAT ACCEPT STATIC PROTRUSIVE REGISTRATIONS AND USE EQUIVALENTS FOR THE REST OF THE MOTION

SUBDIVISION B: INSTRUMENTS THAT ACCEPT STATIC LATERAL PROTRUSIVE REGISTRATIONS AND USE EQUIVALENTS FOR THE REST OF THE MOTION


CLASS IV. AN INSTRUMENT THAT WILL ACCEPT THREE DIMENSIONAL DYNAMIC REGISTRATIONS. THESE INSTRUMENTS ALLOW FOR ORIENTATION OF THE CAST TO THE TEMPOROMANDIBULAR JOINTS AND REPLICATION OF ALL MANDIBULAR MOVEMENTS.

SUBDIVISION A: THE CAM REPRESENTING THE CONDYLAR PATHS ARE FORMED BY REGISTRATION ENGRAVED BY THE PATIENTEX: TMJ ARTICULATOR

SUBDIVISION B: INSTRUMENTS THAT HAVE CONDYLAR PATHS THAT CAN BE ANGLED AND CUSTOMIZED EITHER BY SELECTION FROM A VARIETY OF CURVATURES, BY MODIFICATION, OR BOTH. EX: STUART GNATHOLOGICAL COMPUTER, DENAR MODEL 5A


REQUIREMENTS OF AN ARTICULATOR THE ARTICULATOR MUST ACCURATELY MAINTAIN THE CORRECT HORIZONTAL AND VERTICAL RELATIONSHIP

THE ARTICULATOR SHOULD HAVE AN INCISAL GUIDE PIN WITH A POSITIVE STOP THE ARTICULATOR SHOULD BE ABLE TO OPEN AND CLOSE IN A HINGE-LIKE FASHIONSHOULD ALLOW PROTRUSIVE AND LATERAL MOVEMENTSTHE CONSTRUCTION SHOULD BE ACCURATE,RIGID AND THE MOVING PARTS SHOULD RESIST WEAR. THERE IS ADEQUATE DISTANCE BETWEEN THE UPPER AND LOWER MEMBERS AND THAT VISION IS NOT OBSCURED FROM THE REAR


ADDITIONAL ARTICULATOR REQUIREMENT

A MECHANISM TO ACCEPT A THIRD REFERENCE POINT FROM A FACE-BOW TRANSFER RECORD

THE CONDYLAR GUIDES SHOULD ALLOW RIGHT LATERAL, LEFT LATERAL, AND PROTRUSIVE MOVEMENTS

ADJUSTABLE INTERCONDYLAR WIDTH OF THE ELEMENTS, THE ARTICULATOR SHOULD HAVE PROVISIONS FOR ADJUSTMENT OF

BENNETT MOVEMENT THE INCISAL GUIDE TABLE SHOULD BE A MECHANICAL TABLE THAT

CAN BE ADJUSTED IN THE SAGITTAL AND FRONTAL PLANES A TERMINAL HINGE POSITION-LOCKING DEVICE. REMOVABLE MOUNTING PLATES THAT CAN BE REPOSITIONED

ACCURATELY.


TYPES OF ARTICULATORS AWNI RIHANI PUBLISHED AN ARTICLE IN 1980 DISCUSSING THE CLASSIFICATION OF ARTICULATORS WHICH WERE BASED ON THE ACCEPTABILITY OF THESE FOLLOWING RECORDS:

1. FACE-BOW RECORD2. CENTRIC JAW RELATION RECORD3. PROTRUSIVE RECORD4. LATERAL RECORDS5. INTERCONDYLAR DISTANCE RECORD

A NONADJUSTABLE ARTICULATOR: CAN ACCEPT ONE OF THE FOLLOWING RECORDS

A SEMI ADJUSTABLE ARTICULATOR :CAN ACCEPT THREE OF THOSE RECORDS.

A FULLY ADJUSTABLE ARTICULATOR: CAN ACCEPT THE FOLLOWING FIVE RECORDS: FACE BOW, CENTRIC JAW RELATION, PROTRUSIVE, LATERAL RECORDS, AND INTERCONDYLAR DISTANCE RECORD.


NON ADJUSTABLE ARTICULATORS

FOR COMPLETE DENTURES SIMPLEST TYPE AVAILABLECANNOT ADJUST TO SPECIFIC CONDYLAR MOVEMENTS OF THE PATIENTSALLOW ECCENTRIC MOVEMENTS BUT ONLY AVERAGE VALUESONLY OCCLUSAL CONTACT POSITION CAN BE ACCURATELY REPRODUCEDACCURATE DUPLICATION OF ECCENTRIC MOVEMENTS FOR SPECIFIC PATIENTS IS IMPOSSIBLE REFINING NONWORKING SIDE CONTACTS FOR BALANCED OCCLUSION IS THUS NOT POSSIBLE ON THIS TYPE OF INSTRUMENT.


FOR FIXED PROSTHESIS IT IS USUALLY A SMALL INSTRUMENT THAT IS CAPABLE OF ONLY A HINGE OPENING. THE DISTANCE BETWEEN THE TEETH AND THE AXIS OF ROTATION ON THE SMALL INSTRUMENT IS CONSIDERABLY SHORTER THAN IT IS IN THE SKULLTHIS TYPE OF ARCING MOTION ON THE NONADJUSTABLE ARTICULATOR RESULTS IN STEEPER TRAVEL THAN OCCURS CLINICALLY, RESULTING IN NON-WORKING SIDE PREMATURE CONTACTS ON FABRICATED RESTORATIONS ….


SEMI ADJUSTABLE ARTICULATORS PROVIDES MORE VARIABILTY IN DUPLICATING CONDYLAR MOVEMENTS THAN THE NONADJUSTABLE ARTICULATOR CERTAIN INFORMATION HAS TO BE OBTAINED FROM THE PATIENT TO MAKE PROPER ADJUSTMENT IN THE ARTICULATOR 1) FACE BOW TRANSFER PRIMARY USED IS TO ACCURATELY MOUNT THE MAXILLARY CAST TO THE ARTICULATOR

2) CENTRIC RELATION RECORDSTHE DESIRED MANDIBULAR POSITION IS TRANSFERED TO THE ARTICULATOR

HANAU STATES THAT THE GYSI’S GOTHIC ARCH TRACING IS MOST ADMIRED METHOD

3) ECCENTRIC RELATION RECORDSUSED TO ADJUST THE ARTICULATOR SO THAT IT WILL FOLLOW THE MOST APPROPRIATE CONDYLAR MOVEMENT OF THE PATIENT


NOTETHE NORMAL FORM OF THE SKULL IS CURVED , BUT MOST OF THE ARTICULATORS PROVIDE STRAIGHT PATHWAYIF LATERAL INTEROCCLUSAL RECORD IS TAKEN BEYOND ENE-TO-END (7-10MM) POSITION (POSITION C) – SMALLER BENNET ANGLEIF RECORD IS TAKEN 3-5MM FROM CR – IT WILL MORE CLOSELY RECORD THE IMMEDIATE AND PROGRESSIVE SHIFT OF PATIENT (POSITION B)PROTRUSIVE INTEROCCLUSAL RECORD IS TAKEN AT 6MM


SEMIADJUSTABLE ARTICULATOR USUALLY HAS 3 TYPES OF ADJUSTMENT THAT CAN LEAD TO CLOSE ADAPTATION OF CONDYLAR MOVEMENTS

1) CONDYLAR INCLINATION IT IS THE ANGLE AT WHICH THE CONDYLE DESCENDS ALONG THE ARTICULAR EMINENCEIT IS RECORDED BY PROTRUSIVE INTEROCCLUSAL RECORDTO RECORD THE CONDYLAR DROP THE MAXILLARY CAST IS INTO PROTRUSIVE RECORD AND CONDYLAR SLOT IS ROTATED… IN SAGITTAL PLANE IT CAN HAVE GREATER EFFECT ON THE FOSSA DEPTH AND CUSP HEIGHTSTEEPER THE GUIDANCE – TALLER THE CUSP


2) BENNET ANGLE IT IS THE ANGLE AT WHICH THE ORBITING CONDYLE MOVES INWARD IN LATEROTRUSIVE MOVEMENTMOST ARTICULATORS ALLOW BENNET ANGLE TO BE IN STRAIGHT LINE -SOME ALLOW FOR IMMEDIATE SHIFT AND PROGRESSIVE SHIFTBENNET ANGLE IS CALCULATED BY L= H/8 + 12HAS SIGNIFICANT EFFECT ON THE WIDTH OF THE CENTRAL FOSSAGREATER THE MOVEMENT –WIDER THE ANGLE BETWEEN LATEROTRUSIVE AND MEDIOTRUSIVE PATHWAYS

3) INTERCONDYLAR DISTANCE IT IS MEASURED BY MEASURING THE WIDTH OF THE PATIENT’S HEAD BETWEEN POSTERIOR DETERMINANTS OF FACE BOW AND SUBSTRACTING THE STANDARD AMOUNT THAT COMPENSATES FOR THE DISTANCE LATERAL TO CENTER OF ROTATIONIT IS NOT COMPLETELY ADJUSTABLE – SMALL, MEDIUM,AND LARGEDISTANCE BETWEEN THE ROTATIONAL CENTERS OF THE CONDYLES HAVE AN EFFECT ON THE MEDIOTRUSIVE AND LATEROTRUSIVE PATHWAYS

GREATER THE DISTANCE- SMALLER THE ANGLE www.indiandentalacademy.comwww.indiandentalacademy.com

SEMI ADJUSTABLE ARTICULATORS ARE OF TWO TYPES

ARCON – ARticulator and CONdyle

THE TERM WAS COINED BY BERGSTROM IN 1950

ARCON ARTICULATOR, THE CONDYLAR ELEMENTS ARE PLACED 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 OF THE ARTICULATOR, SIMULATING THE POSITION THE GLENOID FOSSAE IN THE SKULL.

NONARCON ARTICULATOR , THE CONDYLAR PATHS SIMULATING THE GLENOID FOSSAE ARE ATTACHED TO THE LOWER MEMBER OF THE INSTRUMENT, WHILE THE CONDYLAR ELEMENTS ARE PLACED ON THE UPPER PORTION OF THE ARTICULATOR.


ACCORDING TO BECK AND MORRISON, in arcon instrument a constant relationship exist between the occlusal plane and arcon guides of the instrument at any position of the upper member, making the reproduction of the mandibular movement more accurateACCORDING TO VILLA, most important thing in reproduction of protrusive movement on articulator is to establish inclination and curvature of condylar path, its relation to the incisal path and upper cast. The relationship should not be altered a any time, which means that the condylar guide, upper cast and incisal guide must be fixed to upper member as is the condition in natureACCORDING TO WEINBERG, both arcon and condylar instrument produce the same motion , reversing the relationship does not change the guidance produced. Mathematical evidence suggests that neither instrument has specific advantage ACCORDING TO BECK , based on clinical results , no definite superiority could be noted in clinical evaluation of complete dentures constructed on arcon over the condylar instrument

ONE DEFINITE ADVANTAGE OF ARCON ARTICULATOR IS – IT IS ANATOMICALLY “CORRECT,” WHICH MAKES UNDERSTANDING OF MANDIBULAR MOVEMENTS EASIER, AS OPPOSED TO THE NONARCON ARTICULATOR WHOSE MOVEMENTS ARE CONFUSINGLY “BACKWARD” .


ERRORS IN ARTICULATORS

1) AVERAGE ANATOMIC LOCATION OF HINGE AXIS ASSUME A MAXIMUM ERROR OF PLUS OR MINUS 5 MM THE RELATION OF THE JAWS TO THE HINGE AXIS OF THE PATIENT DIFFERS

FROM THE RELATION OF THE CASTS TO THE HINGE AXIS OF THE INSTRUMENT, AN ANTEROPOSTERIOR ERROR OF APPROXIMATELY 0.2 MM WOULD BE PRODUCED

2) ARBITARY LOCATION OF THE ANTERIOR REFERENCE POINT THE RELATIONSHIP OF THE MAXILLARY ARCH TO THE VERTICAL AND

SAGITTAL AXES OF THE PATIENT WILL NOT BE THE SAME AS THAT ON THE INSTRUMENT

AN ELEVATION OF THE ANTERIOR PART OF THE FACE-BOW DECREASES THE PROTRUSIVE CONDYLAR READING AND VICE VERSA

MAXIMUM OF 9 DEGREE REDUCTUION IN PROTRUSIVE READING DUE TO ELEVATION OF FACEBOW CREATES 0.2 MM OF ERROR AT BALANCING CUSP

3) INTERCONDYLAR DISTANCE IT AFFECTS THE MEDIOTRUSIVE AND LATEROTRUSIVE PATHWAY


4) STRAIGHT CONDYLAR PATH ACCORDING TO LUNDEEN, most of the condylar pathways had a curvature

of 3/8” and ¾” MOST ARTICULATORS USE STRAIGHT PATH- WITH STATIC RECORDS ONLY

CENTRIC RELATION AND ECCENTRIC RELATION ARE RECORDED THE MIDPOINT OF EXCURSION PRODUCES MAXIMUM ERROR WITH STRAIGHT

CONDYLAR PATH MAXIMUM ERROR BETWEEN STRAIGHT AND CURVED PATH WITH 1/2” RADIUS

PRODUCES .2MM ERROR

5) TAKING CENTRIC RELATION INTEROCCLUSAL RECORDS AT INCREASED VERTICAL DIMENSION OF OCCLUSION

SIGNIFICANT DISCREPANCY MAY EXIST IF ARBITARY HINGE AXIS IS USED TO MOUNT MAXILLARY CAST AND AN INTEROCCLUSAL RECORD AT INCREASED VERTICAL DIMENSION USED TO MOUNT THE MANDIBULAR CAST – CLOSURE OF ARC OF PATIENT AND ARTICULATOR WILL NOT BE SAME


FULLY ADIUSTABLE ARTICULATOR IS THE MOST SOPHISTICATED INSTRUMENT FOR DUPLICATING THE MANDIBULAR MOVEMENT CAPABLE OF REPEATING CONDYLAR INCLINATION,BENNET ANGLE….

CAN ACCEPT ALL THE FOLLOWING FIVE RECORDS : 1) FACE-BOW RECORD 2) CENTRIC JAW RELATION RECORD 3) PROTRUSIVE RECORD 4) LATERAL RECORDS 5) INTERCONDYLAR DISTANCE RECORD

CERTAIN PROCEDURES ARE REQUIRED TO PROGRAM THE ARTICULATOR 1) EXACT HINGE AXIS LOCATOR 2) PANTOGRAPHIC RECORDS 3) CR INTER OCCLUSAL RECORDS


IN COMPLETE DENTURES EXTREMELY DIFFICULT TO OBTAIN ACCURATE GRAPHIC RECORDS

SO FULLY ADJUSTABLE ARTICULATORS THAT REPRODUCE THE CURVES OF THE BORDER MOVEMENTS ARE UNNECESSARILY COMPLEX.

- IN FIXED PROSTHODONTICSDESIGNED TO REPRODUCE THE ENTIRE CHARACTER OF BORDER MOVEMENTS, A HIGHLY ACCURATE REPRODUCTION OF THE MANDIBULAR MOVEMENT CAN BE ACHIEVED. PERMITS THE FABRICATION OF COMPLEX PROSTHESES, REQUIRING MINIMAL ADJUSTMENT AT THE TRY-IN AND DELIVERY APPOINTMENT.THEY CAN BE VERY USEFUL AS TREATMENT COMPLEXITY INCREASES (E.G., WHEN ALL FOUR POSTERIOR QUADRANTS ARE TO BE RESTORED SIMULTANEOUSLY OR WHEN IT IS NECESSARY TO RESTORE AN ENTIRE DENTITION, ESPECIALLY IN THE PRESENCE OF ATYPICAL MANDIBULAR MOVEMENT).


EVOLUTION OF ARTICULATORS

HANAU ARTICULATORS HANAU-BRAND ARTICULATORS WERE FIRST INTRODUCED IN 1921 BY RUDOLPH HANAU. THE ARTICULATOR WAS DESIGNATED THE MODEL H.

THE HANAU MODEL H SERIES ARTICULATOR THESE MODELS ACCEPT FACE BOW. HORIZONTAL CONDYLAR GUIDANCE WAS ADJUSTED BY PROTRUSIVE INTER OCCLUSAL RECORD. IN THESE INSTRUMENTS, THE LATERAL SETTING WAS CALCULATED BY L=H \ 8+12 THESE WERE ARCON INSTRUMENTS HAVING INCISAL GUIDE TABLE WHICH ALLOWED FOR ADJUSTMENTS IN THREE DIMENSIONS THROUGH A CONSIDERABLE RANGE.

THE HANAU MODEL M KINESCOPE (1923)IN 1923, HE DEVELOPED ANOTHER RESEARCH MODEL, THE HANAU MODEL M KINESCOPE ARTICULATOR WITH DOUBLE CONDYLAR POSTS ON EACH SIDE. BENNET ANGLE IS ADJUSTABLE.


THE HANAU MODEL H2 SERIES (1958) THE HANAU MODEL H2 SERIES WERE DEVELOPED IN 1958.

MODEL H2-O (WITH ORBITAL INDICATOR ATTACHMENT

H2-X (WITH EXTENDABLE CONDYLAR SHAFT)

MODEL H2-PR (WITH CALIBRATED ADJUSTMENTS TO PROTRUDE OR RETRUDE THE CONDYLAR BALLS MODEL 96-H2- NON ARCON WITH ADJUSTABLE CONDYLAR GUIDANCE AND BENNET ANGLE AND FIXED INTERCONDYLAR DISTANCE

MODEL 130 SERIES IS AN ARCON ARTICULATORINTERCONDYLAR WIDTH ADJUSTABLE 94-150MMCONDYLAR INCLINATION 0-60 DEGREESLATERAL ADJUSTMENT 0- 40 DEGREES


MODEL 166 (RADIAL SHIFT) ARCON FIXED INTER CONDYLAR DISTANCE 100 MM HCG ADJUSTABLE FROM 0° - 60° AND HAS ¾ INCH CURVATURE. MEDIAL WALL HAS PRECURRENT SIDE SHIFT CURVATURE OF 3MM RADIUS WHICH IS ADJUSTABLE FROM 0-3 MM

WIDE-VUE MODELS 183 AND 184 HANAU MODELS 183 AND 184 ARE ARCON IN TYPE AND HAVE SIMILAR FEATURES. THE ONLY DIFFERENCE IS THAT THE UPPER AND LOWER FRAMES ON THE 184 MODEL CAN BE SEPARATED.. THE HORIZONTAL CONDYLAR PATH ANGLE IS ADJUSTABLE FROM —20° TO + 60°, AND THE SIDE SHIFT ANGLE IS ADJUSTABLE FROM 0° TO 30°

ACCORDING TO NIKZAD. S. JAVID AND MYRON R.PORTER, “A SIGNIFICANT DIFFERENCE WAS OBSERVED IN MEANS OF CONDYLAR READING WHEN ARTICULATOR WAS ADJUSTED USING LATERAL INTEROCCLUSAL RECORD AND HANAU’S FORMULA” www.indiandentalacademy.comwww.indiandentalacademy.com

WHIPMIX ARTICULATORS

1) 100 SERIES IS A SIMPLE NONADJUSTABLE ARTICULATOR CONDYLAR INCLINATION OF 20 DEGREES INCISAL GUIDE TABLE LATERAL INCLINATION OF 15

DEGREES INTER-FRAME DISTANCE OF 75 MM

2) 1000 SERIES OCCLUSAL ANALYZER ARTICULATOR IT PROVIDES ACCURATE MAXILLARY MOUNTING

REFERENCE POSITION USING THE OR HAMULAR NOTCHES AND INCISIVE PAPILLA FOR THE MAXILLARY MODEL RATHER THAN A FACE-BOW.

FIXED INTERCONDYLAR DISTANCE

3) 2000 SERIES ACCUMOUNT MOUNTING SYSTEM ADJUSTABLE CONDYLAR INCLINATION WITH

CURVED EMINENTIA- IMMEDIATE SIDE SHIFT- FIXED INTERCONDYLAR DISTANCE OF 110 MM www.indiandentalacademy.comwww.indiandentalacademy.com

4) 3000 SERIES TRACKING FOSSAE WHICH ALLOW UPPER AND LOWER FRAMES TO REMAIN TOGETHER DURING EXCURSIVE MOVEMENTS WIDE POSTERIOR ACCESS WHICH GIVES ENHANCED VISIBILITY AND LINGUAL ACCESS ACCUMOUNT SYSTEM ADJUSTABLE CONDYLAR INCLINATION- PROGRESSIVE SIDE SHIFT- FIXED INTERCONDYLAR DISTANCE OF 110 mm

5) 4000 SERIES MAIN DIFFERENCE BETWEEN THE MODEL 4640 ARTICULATOR AND TRADITIONAL WHIP MIX ARTICULATORS IS THE ELIMINATION OF THE CROSSBAR BETWEEN THE UPRIGHTS ON THE LOWER MEMBER. TRACKING FOSSAE WHICH ALLOW UPPER AND LOWER FRAMES TO REMAIN TOGETHER DURING EXCURSIVE MOVEMENTS ACCUMOUNT SYSTEM ADJUSTABLE CONDYLAR INCLINATION- PROGRESSIVE SIDE SHIFT- FIXED INTERCONDYLAR DISTANCE OF 110 MM


6) 8500 SERIES BASED ON RESEARCH BY RENOWNED GNATHOLOGIST DR. CHARLES STUART, THE ORIGINAL WHIP MIX ARTICULATORADJUSTABLE CONDYLAR INCLINATION- PROGRESSIVE SIDE SHIFT- ADJUSTABLE INTERCONDYLAR WIDTH A SPRING LATCH ASSEMBLY HOLDS THE UPPER AND LOWER MEMBERS OF THE ARTICULATOR TIGHTLY TOGETHER AND RETURNS THE UPPER MEMBER TO CENTRIC POSITION

7) 8300 SERIES INTROUDUCED TO REFLECT THE WORK OF LUNDEEN, WRITH AND LEE CONDYLAR GUIDES HAVE ¾” CURVED SUPERIOR WALL AND MEDIAL WALL IMMEDIATE SIDE SHIFT ADJUSTMENT FROM 0-4MM WITH PROGRESSIVE SIDE SHIFT ANGLE OF 6 DEGREE FIXED INTERCONDYLAR DISTANCE OF 110MM


PANADENT ARTICULATORS DESIGN WAS INTRODUCED IN 1978 THE PRINCIPLE IS BASED ON THE WORK OF LEE AND OTHERS A SERIES OF STATISTICALLY SELECTED THREE-DIMENSIONAL ANALOGS OF CONDYLAR AXIS MOTION HAS BEEN DEVELOPED. THE ANALOG FOSSAE FEATURE CURVILINEAR PROTRUSIVE AND MEDIOTRUSIVE PATHWAYS OF APPROXIMATELY ¾-INCH RADIUS THERE ARE FIVE PAIRS IN THE SET WITH PRECURRENT SIDE SHIFTS OF 0.5, 1.0, 1.5, 2.0, AND 2.5MM AND A 6° PROGRESSIVE ANGULATIONTHE CURRENT MODELS WERE INTRODUCED IN 1983LATEST MODELS HAVE MECHANICAL LATCH. THIS KEEPS THE UPPER AND LOWER ARTICULATOR FRAMES JOINED TOGETHER . THERE ARE THREE MODELS—SL, PSL, AND PCL THE SYSTEM WAS DESIGNED TO SELECT THE CORRECT ANALOG AND TO DETERMINE THE CONDYLAR PATH INCLINATION www.indiandentalacademy.comwww.indiandentalacademy.com

DENAR ARTICULATORS

THE DENAR MODEL D4A ARTICULATOR (1968) ARTICULATOR WAS DEVELOPED BY NILES GUICHET IN 1968. IT IS PROGRAMMED FROM TRACINGS MADE WITH A PNEUMATICALLY CONTROLLED PANTOGRAPH.DENAR D5A THE SIDE SHIFT (BENNETT MOVEMENT) ADJUSTMENT IS IN THE MEDIAL WALL AND HAS PROVISIONS FOR BOTH IMMEDIATE AND PROGRESSIVE SETTINGS. A PRECURRENT (ANGULAR) INSERT IS AVAILABLE FOR THE MEDIAL WALL. THERE ARE ALSO NYLON OR ACRYLIC RESIN INSERTS AVAILABLE FOR THE SUPERIOR WALL. AN ADJUSTABLE METAL INCISAL TABLE AND A CUSTOM INCISAL PLATFORM ARE AVAILABLE FOR THE D5A.


DENAR MARK II (1975) A TWO-PIECE INSTRUMENT INCORPORATING A POSITIVE LOCKING MECHANISM THAT CAN HOLD THE TWO MEMBERS TOGETHER AND PERMIT 85 DEGREES OF HINGE MOVEMENT. HORIZONTAL CONDYLAR INCLINATION CAN BE ADJUSTED FROM 0 TO 60 DEGREES AN IMMEDIATE SIDE SHIFT (BENNETT) ADJUSTMENT OF 0 TO 4 MM PLUS A PROGRESSIVE SHIFT ADJUSTMENT OF 0 TO 15 DEGREES. THE CONDYLAR ELEMENTS ARE AT A FIXED 110 MM THE POSTERIOR FOSSA WALL IS INCLINED POSTERIORLY 25 DEGREES TO ALLOW FOR A BACKWARD MOVEMENT OF THE ROTATING CONDYLE AS IT MOVES OUTWARD DURING LATERAL SIDE SHIFT.


SAMTHE SAM 2 ARTICULATOR HAS THREE INTERCHANGEABLE CONDYLAR HOUSINGS THAT INCORPORATE DIFFERENT CURVATURES TO THE SUPERIOR WALL. THE MEDIAL WALL HAS FOUR INSERTS, ONE RECTILINEAR AND THREE CURVILINEAR, WITH INCREASING AMOUNTS OF SIDE SHIFT,THE PIN IS ATTACHED TO THE LOWER FRAME AND TABLE TO THE UPPER FRAME. AN ACCESSORY IS THE SAM MANDIBULAR POSITION INDICATOR (MPI). THE MPI CONSISTS OF A MODIFIED UPPER FRAME WITH SLIDING CUBES INSTEAD OF CONDYLAR HOUSING. THREE-DIMENSIONAL MEASUREMENTS CAN BE MADE IN THE SAME REFERENCE PLANE AT THE CENTER OF ROTATION. THE DATA OBTAINED CAN BE COMPARED BEFORE, DURING, AND AFTER TREATMENT.


LIMITATION OF AN ARTICULATORARTICULATORS ARE MADE PRIMARILY OF METAL-ARE SUBJECT TO ERROR IN TOOLING AND TO ERROR RESULTING FROM METAL FATIGUE AND WEAR

ANY ARTICULATOR DOES NOT DUPLICATE THE CONDYLAR MOVEMENTS-CREATE EQUIVALENT- LIKE MOTION IN THE AREA OF THE TEETH.

THE MOVEMENTS SIMULATED ARE SLIDING MOTIONS, NOT FUNCTIONAL MOVEMENTS-- MAY NOT EXACTLY REPRODUCE INTRABORDER AND FUNCTIONAL MOVEMENTS

STEEL INSTRUMENTS ARE RIGID AND PRECISE WHEREAS THE MUSCLES,LIGAMENT AND BONE HAVE SOME PHYSIOLOGICAL TOLERANCE-PERMITS NECESSARY COMPENSATION OR “GIVE”

MOST INSTRUMENTS ARE LIMITED IN VARIOUS DEGREES IN THEIR ADAPTABILITY TO ALL POSITIONS OF MANDIBLE...

WORKING CONDYLAR MOTIONS IS NOT IS NOT 3DIMENSIONAL MOTION ON THE ARTICULATOR


SELECTING THE ARTICULATOR FOR FABRICATING COMPLETE DENTURESTHE TYPE WILL SOMEWHAT DEPEND ON

(a) THE TYPE OF OCCLUSION TO BE DEVELOPED,

(b) THE TYPE OF POSTERIOR TOOTH FORM

(c) THE TYPE OF EXCURSIVE TOOTH GUIDANCE AND

(d) THE TYPE OF JAW RELATION RECORD

AS IT IS EXTREMELY DIFFICULT TO OBTAIN ACCURATE GRAPHIC RECORDS, SO FULLY ADJUSTABLE ARTICULATORS THAT REPRODUCE THE CURVES OF THE BORDER MOVEMENTS ARE UNNECESSARILY COMPLEX.

AT THE OTHER EXTREME, THE SIMPLE HINGE ARTICULATOR CAN BE RELIED ON TO PRESERVE THE CENTRIC RELATION POSITION

BETWEEN THE EXTREMES IS THE SEMI ADJUSTABLE ARTICULATOR, WHICH WILL ACCEPT AN ARBITRARY FACE BOW RECORD AND INTEROCCLUSAL RECORDS. THIS INSTRUMENT HAS INDIVIDUALLY ADJUSTABLE CONDYLAR GUIDANCES BOTH HORIZONTALLY AND VERTICALLY


SELECTING THE ARTICULATOR FOR FIXED PROSTHESES :IF OCCLUSAL CONTACTS ARE TO BE PERFECTED IN CENTRIC OCCLUSION ONLY, A SIMPLE, STURDY, HINGE TYPE OF ARTICULATOR IS SELECTED

FOR MOST ROUTINE FIXED PROSTHESES, THE USE OF A SEMIADJUSTABLE ARTICULATOR IS SUFFICIENT BECAUSE OF THEIR ACCURACY AND THE EASE WITH WHICH THEY DISASSEMBLE TO FACILITATE THE OCCLUSAL WAXING

IF COMPLETE CONTROL OF THE OCCLUSION IS DESIRED, LIKE IN EXTENSIVE TREATMENT REQUIRING THE RECONSTRUCTION OF AN ENTIRE OCCLUSION A FULLY ADJUSTABLE ARTICULATOR IS DESIRED


SUMMARY

EFFECTIVENESS OF THE ARTICULATOR DEPENDS ON

1) HOW WELL THE OPERATOR UNDERSTANDS ITS CONSTRUCTION AND PURPOSE

2) HOW WELL THE DENTIST UNDERSTANDS THE ANATOMY OF THE JOINTS,THEIR MOVEMENTS AND NEUROMUSCULAR SYSTEM

3) HOW MUCH ACCURACY AND PRECISION ARE USED IN REGISTERING JAW RELATION

4) HOW SENSITIVE THE INSTRUMENT IS TO THESE RECORDS


CONCLUSION “IT MUST BE RECOGNIZED THAT THE PERSON OPERATING THE INSTRUMENT IS MORE IMPORTANT THAN THE INSTRUMENT. IF DENTISTS UNDERSTAND ARTICULATORS AND THEIR DEFICIENCIES, THEY CAN COMPENSATE FOR THEIR INHERENT IN ADEQUACIES”


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