ARTICULATORS
Presented by: Sukh Su kh it K
Introduction Mouth
comprising maxilla and mandible and the two Temporo-Mandibular Joints is the best articulator.
A
mechanical mechanical device simulating simulating these anatomic structures is needed for ease of work and comfort of the patient. This device is called an “ARTICULATOR”.
Definition Articulator is defined as a mechanical instrument that represents the TMJ and jaws to which maxillary and mandibular casts may be attached to simulate some or all mandibular movements. -GPT 7 & 8
History
1756 -
Philip Pfaff
- Plaster/ Slab articulator
1805 -
J.B. Garriot
-Garriot Hinge Joint Articulator
1830,
Howarth & Ladmore HOWARTH‟S ARTICULATOR
LADMORE‟S ARTICULATOR
1840
- James Cameron of Philadelphia“Pole stand” design
Since
1850’s - “Springs”
In
1864, Bonwill introduced the dental profession to theory of tooth guided (balanced ) occlusion along with the anatomical articulators.
1899
- Evens, Hayes, and Bonwill - are the early examples of articulator with “Vertical stop”. 1902 - Kerr Brothers introduced the KERR Articulator with 1) Fixed protrusive and lateral movements. 2) Hinge in the same plane as occlusal planes
Kerr articulator
1910
- ACME articulator was introduced which was elaboration of George B. Snow‟s articulator.
1912
- Gysi -
“Adaptable” articulator
fixed 45-degree incisal guide table. Gysi
continued the exact incisal guide design in his “Simplex” articulator, an “average value” version of the “Adaptable”. He suggested that the slope of “Simplex” incisal table could be altered with use of metal plate and modelling plastic.
Adaptable by Gysi
1916
- Rupert E. Hall - “Alligator
Improved Alligator (1917)
1921 -
The STEPHEN Articulator
•Fixed condylar inclination • Arbitrary lateral movement
1922 -
Hanau model H110
1923 -
Rudolf L. Hanau - Hanau Model M. Kinoscope – Has double condylar posts on each sides, each one for horizontal and lateral condylar guidance.
1927 -
modified H110
Hanau‟s Kinoscope
1928 -
Gysi patented “Trubyte” articulator which had incisal table with guiding lateral edges that could be set to follow incisor point “gothic arch” tracings. It was the first articulator with an adjustable incisal guide assembly. It had 10° lateral wings called as “FISCHER ANGLE”.
TRUBYTE by GYSI
TRUBYTE
1929
Stansberry tripod:
Before 1929, articulators could not accept all the positional records. In this instrument, maxillary cast is mounted in an arbitrary position, later the mandibular cast is mounted with centric relation in plaster. The articulator reproduces positions, not movements.
: 1952 - T RA N S OG R A P H - B Y P A G E
It is a split axis instrument designed to allow each condylar axis to function independent of the other.
1955 - T H E D E N T O G R A P H -
Designed by KILE - was primarily used for complete denture construction. The vertical dimension of occlusion is established by use of carborundum and plaster occlusal rims developed in a generated path by the Patterson method
Dentograph
1955 - T H E ST U A R T A R T IC U L A T O R -
The Stuart gnathologic computer was designed by C.E Stuart in 1955(GNATHOSCOPE).
Features: 1. The upper frame carries all cams that direct the rotations and slidings of the condylar elements and the fossae. 2. The lower frame carries the condylar elements and simulate mandible. 3. The intercondylar distances is adjustable to each patient. 4. The fossa cup can be adjusted 5. The plastic eminence can be altered according to that of the patient if the protrusive and lateral path difference is there. 6. The operating parts are devoid of set screws. 7. The side shift (Bennett) and its timings is cut in to lateral wings. The instrument receive pantograms made in the 3 planes. It also records the amount and character of movements in one plane and in relation to other planes.
1965 - T H E D U P L I FU N C T IO N A L ARTICULATOR -
by Irish - Primarily for use in complete denture construction. It has 2 main purposes; first it records each patient‟s mandibular movements and then without further convertive procedures serves a 3D tripod type of articulator upon which dentures may be constructed and then occlusion balanced.
TRUBYTE
SIMPLEX: The new simplex uses average movements: 1) The condylar guides are inclined at 30 ° 2) Bennett movement of 7.5° 3) The incisal guide table adjusts from 0-30º A mounting jig which doubles to level the occlusal plane is used for arbitrary mounting of upper cast. Alternatively a plane orientation jig positions the lower cast first and it is used for positioning the gothic arch transfer – useful in complete denture construction.
Trubyte & Simplex models
1960 - N E Y A R T IC U L A T O R -
by Dr. D. Pietro. - It was an arcon instrument.
1.
This is the first articulator to have condylar housings that contained adjustable rear, medial and top walls in one assembly.
2.
Intercondylar distance is adjustable.
NEY‟s ARTICULATOR
DENTATUS: This
is another adjustable articulator designed in 1944 in Sweden. The condylar elements are attached to upper member and the condylar path is straight. 1) Bennett angle is calibrated to 40º 2) Inter condylar distance is fixed. 3) This receives hinge axis face bow transfer. Its features are similar to Hanau Model H.
THE
SIMULATOR ARTICULATOR: It was designed by Ernest Granger. It was set with a conventional pantograph. A minigraph could be used when full mouth pantographic tracings is not feasible. It consisted of only two anterior recording plates which were related to casts mounted to the hinge axis. Tracings of protrusive and lateral movements were made. Its Bennett guide can be set by adjustment only and cannot be customized.
Simulator Articulator
CLASSIFICATION OF ARTICULATORS: I. ARTICULATORS BASED ON THEORIES OF OCCLUSION: 1) BONWILL‟S THEORY OF OCCLUSION: W.G.A. Bonwill It is proposed that the teeth move in relation to each other as guided by the condylar controls and the incisal point. It was also known as the theory of the equilateral triangle in which there was a 4 inch (10cm) distance between condyle and between each condyle and the incisal point.
Articulators BONWILL 1854 4”
4”
Bonwill’s
articulator
2)
CONICAL THEORY OF OCCLUSION:
This
proposed that the lower teeth move over the surfaces of the upper teeth as over the surface of cone, generating angle of 45º. And with the central axis of cone tipped at 45º angle to the occlusal plane e.g. Hall „automatic anatomic articulator‟ designed by R.E. Hall
Teeth
with 45º cusps were necessary for constructing dentures on this articulator
ALLIGATOR
3) It
SPHERICAL THEORY OF OCCLUSION:
proposes that the lower teeth move over the surface of the upper teeth as over the surface of sphere with a diameter of 8 inches (20cm). The center of the sphere is located in the region of the glabella and the surface of the sphere passes through the glenoid fossae along the articular eminences or concentric with them. It was proposed by G.S. Monson in 1918.
Monson‟s maxillomandibular instrument
The
draw back of this classification is that provision was not made for variation from the theoretical relationship that occurs in different persons.
II. ARTICULATORS BASED ON THE TYPES OF RECORDS USED FOR THEIR ADJUSTMENT:
Three
general classes of records are used for transferring maxillo-mandibular relationship from the patient to the articulator.
1.
Inter occlusal records
2.
Graphic records
3.
Hinge axis records.
Some articulators are designed for use with only one record where as others can use two or three types of records in combination.
III. ARTICULATOR CLASSIFICATION BASED ON THE INSTRUMENTS FUNCTION:
(At
International Prosthodontic workshop on complete denture occlusion at the University of Michigan in 1972). Class I : Simple holding instruments capable of accepting a single static relationship. Vertical motion is possible, only for convenience. Eg. Slab articulator, hinge joint articulator, barn door hinge.
Class II:
Instruments that permit horizontal as well as vertical motion but do not orient the motion to TMJ via a face bow transfer. A) Eccentric motion permitted is based on average or arbitrary value e.g. Gysi simplex articulator. B) Eccentric motion permitted is based on theories of arbitrary motion. Eg. Monson maxillo-mandibular articulator. C) Eccentric motion permitted is determined by the patient using engraving methods e.g. Howarth articulator, Dentograph. .
Class III: The instruments that simulate condylar pathways, using average or mechanical equivalents for all or part of the motion. Allow joint orientation of the casts via face bow transfer – Hanau mate A) Instruments that accept a static protrusive registration and use equivalents for the rest of motion. Eg. Hanau model H, Dentatus, Bergstrom. B) Instruments that accept static lateral, protrusive registrations and use equivalents for the rest of motion e.g Trubyte articulator, Ney, Kinoscope, Hanau 130-21, Panadent & Stansberry tripod.
Class IV:
Instruments that will accept 3 dimensional dynamic registrations. These allow for joint orientation of casts via a face bow transfer. A) The cams representing the condylar paths are formed by registrations engraved by the patient. E.g. TMJ articulator. B) Instruments that have condylar paths that can be angled and customized either by selection from a variety of curvatures or by modification or both e.g. Denar D4A, Denar 5A (current & simulator.).
IV. CLASSIFICATION ACCORDING TO HEARTWELL Class
I:
These are instruments that receive and reproduce stereograms (pantograms). These can be adjusted to permit individual condylar movement in each of 3 planes. They are capable of reproducing the timing of the side shift of the orbiting (balancing) side & its direction of the rotating (working) side.
CLASS II: They do not receive the stereograms. Type 1 (Hinge): This type is capable of opening and closing in a hinge movement, a few limited non-adjustable excursive like movements. Type 2 (Arbitrary ): This is designed to adapt to specific theories of occlusion or is oriented to a specific technique. Type 3 (Average): This type is designed to provide condylar element guidance by mean of averages, positional records of mini recorder systems. Type 4 (Special): This type is designed to be used primarily for complete dentures.
Class I McCollum‟s Gnathoscope. Granger Gnathoscope. Hanau Kinoscope Cosmex Stuart Gnathologic computer TMJ stereographic Denar D5A
Class II (Type 1) :
Type 2 :
Barn Door hinge
Monson
Stephens
Handy II
Gariot
The Correlator
Crescent
Transograph
Gysi
The Gnathic Relator
Trubyte Simplex
Verticulator
ACME
Twinstage occluder
Bonwill
Type 3: House Dentatus Hanau (several models) Whipmix Denar – Mark II and Omni model TMJ – mechanical fossa & molded fossa models Panadent Type 4: Stansberry tripod Kile dentograph Irish Dupli-Functional
V. Gillis (1926), Boucher (1934) and Kingery (1934) Classification – Adjustable
adjustable
and Non
Beck‟s (1962)
-Suspension
tripod
instrument-The axis-The
VII. Weinberg (1963) -Arbitrary –Positional -Semi-adjustable -Fully adjustable
VIII. Posselt‟s (1968) -Plain line - Mean Value - Adjustable
IX. Sharry (1974) -Simple -Fixed
-Hinge type
guide type
-Adjustable
X. CLASSIFICATION BY Riliani (1980) FULLY ADJUSTABLE Accept the following 5 records: Face bow Centric relation Protrusive Lateral records Inter-condylar distance record SEMI-ADJUSTABLE Accept the following 3 records: a) Face bow b) Centric relation c) Protrusive NON-ADJUSTABLE Can accept one or two of the following records a) Face bow b) Centric relation c) Protrusive
REQUIREMENTS OF AN ARTICULATOR
-It should hold casts in correct horizontal and vertical relationship. -It should provide a positive anterior vertical stop (incisal pin) -It should accept a face bow transfer record utilizing anterior reference point. -It should open and close in a hinge movement. -It should allow protrusive and lateral jaw motion. -The moving parts should move freely and be accurately machined. -The non-moving parts should be a rigid construction made of non corrosive material. -The patient‟s casts must be easily removable and attachable to the articulator without losing their correct horizontal and vertical relationship. -The design should be such that there is adequate distance between the upper and lower members and that vision is not obscured from rear. -The articulator should be stable on laboratory bench and not too bulky and heavy.
A D D IT IO N A L R E Q U IR E M E N TS :
-Adjustable horizontal and lateral condylar guide elements. -The condylar elements as a part of lower frame and condylar guides as a part of upper frame. -A mechanism to accept a third reference point from a face bow transfer record. -A terminal hinge position locking device. -Removable mounting plates that can be repositioned accurately. -An adjustable incisal guide table. -Adjustable intercondylar width of the condylar elements.
USES: Primary Purpose: •To hold opposing casts in a predetermined fixed relationship. •To open and close. •To produce border and intra-border diagnostic sliding motions of the teeth similar to those in the mouth. Other uses: a) To diagnose if the patient has TMJ problem. b) To plan dental procedures that involve positions, contours and relationships of both natural and artificial teeth as they relate to each other. c) To aid in fabrication of dental restorations and lost dental parts. d) To correct and modify completed restorations eg. In cast crown. e) Can be helpful in teaching and studying of occlusion and mandibular movements.
ADVANTAGES: “The patient’s mouth is the best articulator”. The final test for a dental restoration is the occlusal harmony obtained when the restoration is placed in the patient‟s mouth. But still mechanical articulators have many advantages over the mouth. 1. Better visualization of the patient‟s occlusion, especially from lingual view. 2. Patient co-operation is not a factor. 3. The refinement of complete denture occlusion in the mouth is extremely difficult because of shifting denture bases and resiliency of the supporting tissues. 4. Reduced chair time and patient appointment time 5. More procedures can be delegated to auxiliary personnel. 6. The patient‟s saliva, tongue & cheeks are not the limiting factors.
LIMITATIONS: 1). An articulator is a mechanical instrument made of metal. 2). The articulator is subject to error in tolling and errors resulting from metal fatigue and wear. 3). It is unlikely for any articulator to duplicate condylar movements in the TMJ. 4). The movements simulated are empty mouth sliding motions, not functional movements.
SELECTION OF AN ARTICULATOR FOR COMPLETE DENTURE
If occlusal contacts are to be perfected in centric relation only, then a simple hinge articulator can be selected. If denture teeth are to have cross arch and cross tooth balanced occlusion, then minimum requirement is semi adjustable articulator e.g. Hanau or Whipmix. If complete control of occlusion is desired, a completely adjustable, 3-dimensional articulator is selected.
These complicated articulators pose some problems for use in making complete dentures because of the resiliency of the soft tissues of the basal seat on which recording bases must rest. As the resiliency permits some movement of the bases in relation to the bone, the records made are not necessarily records of the true path movement of the bone.
Selecting The Articulator For Fixed Prosthodontics
Choice of articulator must be made on the basis of what is expected of it : If
occlusal contacts are to be perfected in centric
occlusion only, a simple, sturdy, hinge type of articulator will suffice For
most routine fixed prostheses:
The
use of a semi-adjustable Arcon articulator has become more
widely used because of their accuracy and the ease with which they disassemble to facilitate the occlusal waxing required for cast
Selection of an Articulator for RPD A
simple hinge or a non-adjustable articulator is selected for class III partially edentulous patients
For
most class I & II partial dentures – Semiadjustable like Hanau, Whip-mix
Fully
adjustable articulator is usually limited to those patients needing a removable partial denture, wherein the entire occlusal scheme is to be developed at one time by the wax additive technique. Stuart articulator is generally used.
Articulator use vs time vs cost lots
lots
Amount of adjustment
Difficulty of use
Cost
none
none
Hand Av Held Value
S-A
Fully Adjustable
ARCON V/S NON ARCON Arcon type:
Non Arcon:
Arcon
Condyles
- The term was coined by Bergstrom.
Instrument
with condyles in the lower member and condylar guides on the upper member i.e. lower member is movable.
are on upper member and condylar guidance on lower member.
Beck (1956) states that the constant relation of occlusal plane and arcon guides exists at any position of the upper member and thus duplication of mandibular movement is more accurate in arcon type.
Weinberg
(1963) concluded that the arcon and non arcon type produce the same guidance.
Applications and limitations of non adjustable articulators Permit
only a simple hinge opening around a horizontal axis whose distance from the casts is arbitrarily determined and less than the distance between patient TMJ‟s and teeth. Cannot simulate mandibular movements or positions outside patient‟s mouth and are inadequate for occlusal diagnosis. Can observe static relationships. Restoration may have to be adjusted in the mouth
Applications and limitations of semi adjustable articulators
They are widely used in diagnosis and treatment in complete denture prosthodontics, FPD and RPD. Their limitations in providing only an approximation of true mandibular movements are acceptable when adequate anterior guidance is present. When guidance is reduced, it becomes more critical to use an instrument which mirrors the movements more exactly so that the occlusal anatomy may be reproduced in the laboratory to create intercuspal position contacts yet disclude in other positions. If restorations are made on semi adjustable articulators, the occlusal adjustment needed in lateral excursion becomes progressively less acceptable.
Applications of fully adjustable articulators Fully
adjustable articulators are indicated when restoring opposing teeth in complex cases, with minimal anterior guidance or group functions.
They
enable the cusps and grooves to be positioned correctly with respect to the direction of lateral and protrusive movements
Greatly
reduce the amount of occlusal adjustment required when restorations are tried in the mouth.
AVERAGE VALUE ARTICULATOR: Here simple hinge is replaced by a mechanism which allows the upper member to be moved upward and backward relative to lower. This path of movement is at same inclination on either side, about 30º angle is made by condylar guide to occlusal plane in average individual. Anterior part of the upper member is supported by incisal guide rod through upper and incisal guide table on lower. The angle of incisal guidance is about 10 to 15 degrees. For mounting, according to Bonwill concept, an incisal guidance rod and a horizontal bar through two pillars is included. Can be used for routine complete denture construction.
Average Value Articulator
HANAU ARTICULATORS Hanau Model H (Arcon): It was designed in 1923 by Rudolf L. Hanau originally for complete denture construction. 1. Condylar guidance were on an axle and were part of upper frame (Arcon) 2. Intercondylar distance is fixed at 110 mm. 3.Condylar elements functioned in a slot type guidance mechanism and horizontal condylar guide can be adjusted from – 40 to + 80 degrees (Horizontal condylar inclination set by protrusive records)
4. The (lateral guidance side shift) adjustments can be adjusted from 0-20 degrees. This was calculated by Hanau in formula L = H/8 + 12 {L = Lateral condylar angle in degrees. H = Horizontal condylar inclination in degrees} The derivations for this equation are not known and so the validity is questionable since large changes in the horizontal condylar inclination angle will result in only a few degrees change in the side shift angle. 5. Also accepts a face bow transfer.
Hanau Model H
HANAU H2 (MODEL 96) (Non Arcon):
It is a condylar or non arcon type with the condylar guidance controls attached to lower member of articulator. The original features of Hanau H have been retained and additions, auditory pins have been added to the condylar guidance mechanism to receive an ear piece face bow. The lateral adjustment for side shift has been increased from 0-30º Intercondylar distance is fixed at 110 mm. Incisal guide table is adjustable both in sagittal and frontal planes (Single sagittal, right and left frontal).
HANAU H2 (MODEL 96) (Non Arcon):
HANAU ARCON H2 : (MODEL 158)
Introduced by Hanau in 1977. Fixed intercondylar distance – 110 mm and accepts a face bow transfer. Adjustable horizontal condylar guidance and Bennett controls. Standard incisal guide table as in H2. It can be used with facia face bow, an ear piece or twirl bow. The face bow can be aligned to the Frankfort horizontal plane by means of an orbital pointer. Without an orbital pointer, the incisal plane is adjusted so that it is in level with the notch on the incisal pin which is 47 mm below the horizontal condylar plane or 54 mm below the Frankfort horizontal plane. The Bennett angulation is either calculated by Hanau‟s equation or is adjusted by lateral interocclusal records. If adjustable axis face bow is to be used, then the articulator must be equipped with extendible condylar shafts as in H2.
Hanau model 158
HANAU WIDE VUE (Models 183 & 184) The Hanau wide VUE I and Hanau Wide VUE II are the new articulators. Arcon and fixed intercondylar distance 110 mm. Difference is that Hanau wide VUE I has a closed condylar track and Hanau wide VUE II has an open condylar track which allows upper member to be removed. Wide VUE II has condylar retainers to avoid accidental separation of upper member. A micrometer protrusive – retrusive condylar adjustment is available which is accurate to 0.05 inch. Horizontal condylar angle is adjustable from –20 to +60 degrees and side shift angle adjustment is from 0 – 30 degrees (same as H2). The straight incisal guide pin or with adjustable foot is available. The straight pin has dual ends – chiesel and spherical and extends above the upper member to act as a third point stability when inverting the articulator for mandibular cast mounting. 3 incisal guide tables are available: mechanical, flat and pantacrylic table.
Hanau wide vue
Hanau model 184 Hanau model 183
3 types of incisal guide tables: mechanical, plastic and pantacrylic
HANAU RADIAL SHIFT (MODEL 166)
First produced in 1981. Arcon, intercondylar distance is 110mm, right and left centric latches, upper member can be removed for waxing . Can be used with facia, ear piece face bow and twirl bow.
The condylar guidance is designed to incorporate a curved immediate side shift (radial shift) with adjustable progressive Bennett angle of 0-60 degrees.
The radial shift adjustment has 3mm radius and allows up to3mm of radial shift. The condylar guidance is adjustable horizontally and has a curved superior wall with 0.75 inch radius. A straight incisal guide pin or an incisal guide table with adjustable foot is available –mechanical, flat and pantacrylic table are available.
Hanau radial shift
HANAU MATE –165: (Average articulator)
Fixed intercondylar width –110mm. 30 degrees fixed horizontal condylar inclination. 15 degrees fixed progressive side shift angle (Bennett). 10 degrees protrusive and lateral incisal guide table. Upper frame can be separated by loosening two locks. Receives most average face bows. Casts can be mounted without mounting plates. Excellent lingual visibility.
XP-51 ARTICULATOR (JPD 1975 VOL 33, Pg 158)
The Hanau XP-51 is arcon type with fixed distance of 90mm between the condylar posts. The articulator is adjustable to lateral interocclusal records . The adjustable guides with in the condylar housing are the Bennett guides, horizontal condylar guides and an adjustable posterior wall which can be adjusted to the position of the working side condyle in lateral movement. When adjusted, the wall contacts and forms a guiding position for the working side condyle further, the posterior wall combines to compensate for the lack of an intercondylar distance on the articulator. The angle is called the ‘Compensating angle’ . • Casts may be removed from the articulator and returned to their original position with disposable mounting hinges. The articulator can be locked in centric relation position when casts are mounted and this remains constant even after changes of the posterior wall of the condylar guidance.
TELEDINE HANAU MODEL 194 (JPD 1995 Vol.74) Features: Modification of the condylar mechanism by incorporating the curved component of movement to the immediate side shift. This permits the working condylar element to follow a curved path as it shifts laterally. Study: This study investigated the acceptability of lateral interocclusal records. 60 lateral interocclusal records were made for 30 edentulous subjects and the acceptability of the records was evaluated by use of the split cast mounting procedure. Out of 60 records, 52 records (87%) were accepted by this articulator.
TELEDINE HANAU MODEL 194
THE 130 UNIVERSITY SERIES:130-21 MODEL Arcon,
used for occlusal corrections.
Intercondylar
width adjustment from 94-150mm.
Split
vertical and lateral compound axis permits adjustment from -30 to +30 degrees in both planes.
Lateral
condylar angle is adjustable from 0-40 degrees.
Upper
member may be separated from the lower member by loosening a retention lock.
130-22 MODEL:
Non-arcon
used for the restoration of natural teeth .
Variable
intercondylar width settings of 94-150 mm.
Upper
and lower members can be separated.
130-28 MODEL: Arcon check-bite articulator. For standard fixed and removable prosthodontic situations. Intercondylar adjustment is 94-150mm. Condylar inclination adjustment of 0-60 degrees, lateral adjustment of 0-40 degrees. 130-30 MODEL: Only addition of a special retrusive –protrusive condylar adjustment.
WHIP MIX ARTICULATORS The Whip mix articulator and Quick mount face bow were introduced by Dr. Charles Stuart in 1963. His main objective was: (1) Aid in the teaching of principles of occlusion, for better diagnosis of the occlusion of natural teeth. (2) To provide simplified instrument for fabrication of prosthodontic restorations.
Whipmix Articulator
Normal Features: (1) Intercondylar distance is adjustable S(96mm), M(110mm) and L(124mm) by means of removable condylar guidance spacers along the instrument‟s horizontal axis.
(2) Horizontal condylar inclinations are set by means of lateral or protrusive interocclusal records. (3) Amount of Bennett movement is set by lateral interocclusal records. (4) The upper and lower members are mechanically attached by means of spring latch assembly.
WHIPMIX ARTICULATOR- adjustable intercondylar width
Condyle elements are moved to center holes of lower frame to correspond to the „medium‟ registration.
1mm shims for lateral shift
MODEL 8300: (reflects the work of Lundun, Wirth, Lee and others) The condylar guides have ¾”
curved superior walls and a medial wall,
immediate
side shift adjustment from 04mm with a progressive angle of 6 degrees.
Condylar locking pin is there and condylar elements are fixed at 110mm.
Model 8300
MODEL 8340 The
casts are interchangeable between articulators through a special fixture called as “accumount” with which a special mounting plate table is precisely attached to the lower frame.
The
relationship is then checked to verify precise alignment between upper and lower frames
Model 8340
MODEL 8800:
an
additional ½” space to mount the maxillary cast.
MODEL 9000: Similar
to 8800 except the lower frame is ½” taller to provide more space for mounting the mandibular cast.
MODEL 9800: Combines
the upper frame of model 8800 with the lower frame of model 9000 to provide the greatest distance between the upper and lower frames. These models can have condylar locking screws which can be positioned against condylar elements to permit only hinge action and action and helps in mounting procedures. Models with this feature are designated as 8500 A, 8800 A, 9000 A and 9800 A.
MODEL 8500: Original 8500: Original model
The condylar elements on the lower frame are adjustable to 3 positions.
Intercondylar distance can be adjusted between 96 mm, 110 mm, and 124 mm.
The condylar guides in the upper frame are aligned with the condylar elements of the lower frame by either removing or adding appropriate amount of spacers on the shaft of condylar guides .
The condylar guides can be adjusted from 0-70 degrees horizontal condylar inclination.
The medial walls are adjustable from 0-45 degrees to progressive side shift, posterior walls are straight.
Guide table: The articulator is available either with an adjustable mechanical guide table or a flat or a dimpled plastic incisal guide table.
The
latest version of Whip Mix articulators have been designated model DB 2000 and DB 2200. There is also an interchangeable 2240 model.
The
posterior viewing and access space has been increased. The additional inter-frame distance has been increased to 114mm (41/2inches) to provide more space for bulky casts.
A quick-acting centering latch system
Model 2000 & 2200
Bilateral heavy elastics connect the condylar assemblies to the vertical frames of the lower member. These elastics Prevent separation of the upper and lower frames during excursive movements. Maintain the orbiting condylar element against the medial wall of the condylar assembly during a lateral movement Tend to return the condylar element back to CR after releasing lateral movement pressure and Provide a “positive feel” to any excursive movement during laboratory manipulation.
MODELS 2200 & 2240: The
models 2200 and 2240 are identical with the exception that the 2240 features the Accumount System, which allows interchanging of mounted casts between other 40 series. The mechanical features in the condylar assembly are identical to those of the 8300 series.
Whipmix 2240
MODEL 2000:
The model 2000 articulator is the same as the model 2200 except that The medial wall is curved at its end to provide for a curvilinear movement of the orbiting condylar path. Shims of 1 and 2mm thickness are provided. The 1mm shim, when in place allows 1mm of curvilinear side shift in the first millimeter of advancement. The 2mm shim allows for 2mm of curvilinear side shift in the first 2mm of advancement. The unused shims are stored in a compartment of a special designed Hex wrench.
PANADENT ARTICULATORS: introduced in 1978 by Robert Lee and current models were introduced in 1983
arcon; with fixed intercondylar distance 110 mm. It utilizes interchangeable, preformed, curved analog fossae for condylar pathway. The progressive side shift varied from 5-7 degrees generally with an average of 6 degrees. Fossae analogs are available with average lateral pathways and immediate side shifts from 0.5 – 2.5 mm. Lateral interocclusal records or the Axi-path recorder are utilized to determine the amount of side shift and the steepness of the horizontal condylar inclination. The latest modification is Dynalink panalock mechanical latch which permits an opening movement of 180 degrees.
Panadent articulator
3
models are available: SL, PSL & PCL. The later two models are machined to within 0.01 mm accuracy that permits the interchanging of mounted casts between different articulators.
PSL
model has a less complicated straight incisal guide pin as does the SL model.
Both
a plastic and an adjustable metal incisal guide table are available with all 3 models.
SL
PCL with curved incisal pin
Selection of an Analog: Quick analyzer tracing extraoral device is used to determine condylar path inclination. • Different analogs can be mixed for each side if different amount of side shift is present. • The analogs and their angulation can be determined with positional lateral records.
Analogs for Panadent articulator
TMJ ARTICULATORS: Kenneth Swanson and introduced in 1965.
Condylar inclinations adjustment from 10 – 55 degrees Progressive side shift adjustment of 0-35 degrees. The superior wall has a 3 degrees slant which produces „FISHER ANGLE‟ when the mediotrusive pathway portion is steeper than the protrusive pathway. The incisal guide pin is curved both a plastic and an adjustable mechanical incisal table . A mechanical guidance fossa accessory is available and can be easily inserted in the articular fossa housing. A series of 5 pre made fossae analogs are available with curvilinear superior surfaces based on average from an analysis. Hinge opening of the locking device is 115 degrees.
Each set contains pairs of fossae with inclinations of 28, 35, 40, 45 and 50 degrees in degrees in different colours for colours for easy identification. identification. Each analog has a 0.5 mm pre current side shift with a 7 degree progressive angle.
Custom analog fossae are fossae are formed from intraoral stereographic tracings and is called as „ stereographix’ . Blank fossae boxes are filled with acrylic resin and curvilinear curvilinear guidance paths and side shift are produced.
The articulator has a spring latch to latch to return upper frame to centric relation position.
Mini-articulator: Smaller version. The intercondylar Mini-articulator: distance is limited from 110-150 mm and has straight incisal guide pin.
Denar 4A (NILES GUICHET IN 1968)
PROGRAMMED FROM TRACINGS MADE WITH A PNEUMA PN EUMATICAL TICALL LY CONTROLLED PANTOGRAPH. Advantage : Saves time and and effort effort needed to manually transfer the recordings and to program the articulator.
Denar 5A
DENAR ARTICULATORS DENAR – D5A:1968 Dr. Niles Guichet Features: Adjustments to the guidance surface are possible in 3 planes of space. The side shift adjustment is in the medial wall and has provision for both immediate and progressive settings. A pre current insert is available for the medial wall and nylon or acrylic resin inserts are available for the superior wall.
INCISAL TABLE: An adjustable metal incisal table and a custom incisal platform are available. Adjusting the foot of the incisal pin, allows movement in the articulator to develop an area of occlusion in centric relation. The incisal platform can be used to hold self-curing acrylic resin adjusting the horizontal and vertical overlap of the anterior teeth. Denar reference plane locater and marker is useful for locating the anatomical landmarks, posterior and anterior reference points. Pantronic – A digital recorder is available in which the condylar guidance settings are automatically determined.
DENAR MARK II: 1975 Condylar
elements are fixed at 110 mm intercon dylar distance. Adjustable intercondylar distance (110 – 120 mm) is also available.
The
horizontal condylar inclinations can be adjusted from 0 – 60degrees.
Has
an immediate side shift (Bennett) adjustment of 0 – 4mm
Progressive
shift adjustment of 0 –15 degrees.
Denar Mark II
AUTOMARK nonadjustable
articulator with fixed guidances.
The
medial wall has a 7º progressive angulation.
The
lower frame is similar to that of the Mark II
Four
types of incisal guide tables and incisal guide pins combinations are available and are interchangeable from one articulator model to another.
AUTOMARK
Once the face-bow record has been made on the patient, the side arms are removed and set aside. The transfer jig is then inserted into the incisal guide table slot and attached to the lower member of the articulator. The face-bow fork is now properly related to the articulator for mounting of the maxillary cast. The advantage of this face-bow is that the same bow can be used with additional face-bow forks and transfer jigs for taking multiple face-bow records. Whipmix, Hanau and Panadent have introduced similar systems. To help in infection control measures, the disposable Best-Bite System is available. It is composed of a wax bite fork and nonmetal components in the transfer jig.
The
omni articulator
It was introduced in 1984 This design allows one to exchange closed (tracking) fossa for open fossa with a positive locking latch. When the articulator is equipped with the open fossae which are identical to the Mark ΙΙ fossae, and a positive centric latch, it is called the Omni Mark. when it is utilized with closed track fossae and centric lock screws it is called the Omni Track. The purpose of this model is an attempt to better meet the requirements for complete, removable and fixed partial denture fabrication in one articulator. The Omni model is adaptable to a wide range of accessories of other models that can maximize its versatility.
VIRTUAL ARTICULATORS Virtual
Articulators are also called as „SOFTWARE articulators‟. They are not concrete but exist only as a computer program. They comprise of virtual condylar and incisal guide planes. Guide planes can be measured precisely using jaw motion analyser or average values are set in the program like average value articulator.
The
Virtual Articulators are able to design prostheses kinematically. They are capable of simulating human mandibular movements, by moving digitalized occlusal surfaces against each other and enabling correction of digitalized occlusal surfaces to produce smooth and collision-free movements. There are two types of Virtual Articulators A. Completely adjustable virtual articulator B. Mathematically simulated virtual articulator
Completely Adjustable Virtual Articulator
Designed to record the exact movement paths of the mandible with an electronic jaw movement registration system called „Jaw Motion Analyser‟. It is an ultrasonic motion capture device that is comprised of an ultrasound emitter array that is bonded to the labial surfaces of the mandibular teeth using a jig customized with cold cure acrylic and a sensor array located on a head frame secured to the patient's head. The spatial coordinates of the two condylar points and an infraorbital point are pre-selected by the user to define a plane. Movements of at least three points relative to this plane during jaw motions are saved in an ASCII file. Two condylar points and the base center of the T-attachment pointer attached to the jig are the three points. It is further planned to integrate the system into the design and correction of occlusal surfaces in CAD- systems.
Mathematically Simulated Virtual Articulator Based
on a mathematical simulation of the articulator movements. It is a fully adjustable three dimensional virtual articulator capable of reproducing the movements of a mechanical articulator. Offers possibilities not offered by some mechanical dental articulators, such as curved Bennett movement or different movements in identical settings . It behaves as an average value articulator.
Programming Pre
of Virtual Articulators
requisite for visualization on screen is 3D scanning/digitizing of tooth surface or restorations or denture models using 3D scanner.
CONCLUSION
Since a number of articulators are available for the fabrication of dental prostheses, there is considerable controversy as to which articulator is the „best‟ for a particular dental procedure. However, the success or failure of the final restoration is more dependent on the operator of the articulator than on the articulator itself. “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 inadequacies.” - Carl O. Boucher
