Articulators final presentation in prosthdontics

in detail explanation on articulators

2. Page of contents
•Introduction
•Definitions
•Uses
•Advantages
•Limitations
•Purpose
•Evolution
•Requirements
•Absolute
•Minimal

3. •Laws of articulation
•Factors of articulators
•Immutable
•Mutable
•Arcon and non arcon concept
•Selection of articulators
•Conclusion
•References

4. Definitions
•Articulation : Static and dynamic contact
relationship between occlusal surfaces of
teeth during function
GPT VIII
Articulators : Mechanical instrument that
represents the TMJ and jaw members to
which maxillary and mandibular casts
may be attached to simulate some or all
of the mandibular movements
GPT VIII

5. “ Primary function of an articulator is to act as the patient in
absence of the patient ”

6. ‘ Articulator can simulate but cannot duplicate al
possible mandibular movements ’

7. ‘ Patient’s mouth is the best articulator ’
….???

8. Advantages
Beter visualization of patient’s
occlusion – lingual side
Provision of lingual view in
complete denture teeth
arrangement
Patient cooperation not a factor of
concern
Refinement of complete denture
occlusion
Precious time saved !
Lab procedures delegated to
dental auxillaries
No interference from patient’s
saliva tongue or cheek
Realeff effect is eliminated

9. Limitations
Mechanical construction ! Erro rs due to ... Wear
and tear
‘ Articulator can simulate but cannot duplicate al
possible mandibular movements ’
“ Interocclusal records are no better than the
bases from which they are made ”
Effectiveness of an articulator ….
“ it must be recognized that the person operating the instrument is more
important than the instrument . If the dentists understand articulators and
their deficiencies they can compensate for their inherent inadequacies ”

10. Requirements
Not as sophisticated as for fixed prosthodontic
procedures !...
“Interocclusal records made for complete dentures are
no better than the ‘bases’ upon which they are made ”
Movement of bases Movement of ‘bases’

11. Requirements
Minimal Articulator Requirements
1. Should hold casts in the correct horizontal and
vertical relationship(to maintain centric position)
2. The patients cast must be easily removable and
attachable to the articulator with out loosing
their correct horizontal and vertical relationship.
3. Should have a incisal guide pin with positive stop
which is adjustable & calibrated.
4. Should accept a face - bow transfer record.

12. 5. Should open and close in hinge movements
6. The moving parts should move freely & should be
accurately machined.
7. The non- moving parts should be of rigid
construction.
8. Adequate distance between upper & lower
members so that vision is not obscured from the
rear.
9. Should be stable on the laboratory bench, not too
bulky & heavy.

13. 1. The condylar guides should allow right lateral, left
lateral, & protrusive movements.
2. The condylar guides should be adjustable
horizontally.
3. The articulator should have provisions for
adjustment of Bennett movement.
4. The incisal guide table should be a mechanical
table that can be adjusted in the sagittal &
frontal planes or a table that can be customized
with autopolymerizing resin or by grinding.
Additional Requirements

14. Optional Requirements
1. Adjustable intercondylar distance (influences the
character & inclinations of the grooves and cusps)
2. An immediate Bennett adjustment (primarily
influences the width of the central grooves of the
posterior teeth)

15. Evaluation of basic concepts of articulation
Motion : I dimension
Curvilinear
Rectilinear
A 3 dimensional curved motion has an axis of rotation in each of the 3 planes
of space ; 3 axes being perpendicular to each other .

16. Human motion : curved movement
Most untrained mandibular motion is elliptical in nature
Axes of rotation in 3 planes translate simultaneously as
rotation occurs

17. First requirement for reproducing any motion – 3 fixed
points in space
Starting point
Path
End position

Orientation to act as a fixed base
Mandibular movements
and inter occlusal records
“ Make possible the transfer of the physiologic axes of rotation to
an instrument as the mechanical axes of rotation ”

18. Can the most sophisticated articulator accurately simulate
the physiologic axes ???.....
Physiologic tolerance Biologic variability
Finite measurements impossible :
permanent source of error !

19. What is the physiologic axes of rotation ?....
Axes of rotation in 3 planes of space are associated with
elliptical motion of mandible --- inter relationship
significant

20. Clinical importance of hinge axis : orientation of maxillary cast on
the articulator and accurate transfer of interocclusal records
Kinematic face bow Arbitary face bow
1. Conventional bows
2. Non right angle
system

21. Definite 3 dimensional relationship between the maxillary
dental arch and the starting position of the condylar motions
Relationship of a fixed base to movement

22. Evolution of Articulators
THE PLASTER ARTICULATOR
•Described by Phillip Pfaff in 1756 and Jean
Garriot in 1805
•A plaster extension on the distal portion of the
mandibular cast was grooved to serve as a
guide for a plaster extension of the maxillary
cast.
•Slab articulator

23. ‘ Garriot Articulator Myth ’

24. THE ADAPTABLE BARN DOOR
HINGE
•Capable of opening and closing only in a
hinge movement.
•Has an anterior vertical stop, which is
usually a carriage or machine bolt.
•Not flexible, lateral movement is held to
a minimum.

25. Anterior vertical stop, which is usually a
carriage or machine bolt

26. Early attempts to record mandibular
movements
Balkwill (1866) and C E Luce (1889) downward movement
of the condyles during mandibular excursions.
HAYES ARTICULATOR
Fixed curved condylar paths and
individual condylar tension springs
Likely the first articulator with arcon
concept
Fixed condylar guide articulator with non adjustable
condylar elements

27. Fixed condylar guide articulators

28. Gritmann articulator
Average 15 degree condylar path
Balkwill-Bennett angle ‘‘to represent the average oblique
descent of the condyle’’

29. GYSI SIMPLEX
ARTICULATORS
•Was introduced as a mean
value articulator in 1914
•Did not require great
technical ability to operate.
•The condylar guidance of is
fixed at 33 degrees and is
shaped like the ogee path.

30. THE STEPHAN ARTICULATOR
•Developed in 1921
•Similar in design to Gariot hinge articulator
except it has a fixed condylar inclination &
allows for an arbitrary lateral movement.
‘Crescent articulators’

31. Attempts to reproduce mandibular movements …
Searching for a solution to the puzzle !!!...
No generally known practical clinical method existed for recording the
direction of the patient’s condylar paths and accurately transferring the
casts with the measurements to an articulator capable of accepting those
records
The First “Adjustable Condylar Guide” Articulator
William E. Walker
“ Considerable variation in the downward movement
of the condyles and to construct an articulator based
on this principle ”

32. 1.‘ Walker Bonwill articulator
2. Walker physiologic articulators

33. “Christensen’s Phenomenon”
Another Rediscovery
Reported his observations of the space that occurs
between the maxilla and mandible during protrusion
Christensen’s phenomenon : coined by Ulf Posselt
…… Or Balkwill’s Phenomenon ??? ..

34. George B. Snow’s Report to the Profession on the
Solution to the Puzzle
“ A practical and easily applied clinical method for using an
adjustable articulator in denture construction ”….
Improvement of Gritmann articulator

35. THE NEW CENTURY ARTICULATORS
•Adjustable condylar paths and adding a tension spring,
•The rotation centers were placed 4 inches apart in
accordance with Bonwill's theory.

36. THE ACME ARTICULATOR
•The incisal pin rests on a changeable incisal guide.

37. THE KERR ARTICULATOR
•Developed by the Kerr brothers in 1902
•Adjustable condylar guides and arbitary bennet movement settings
•Hinge is located on approximately the same plane as the occlusal plane of
the mounted cast.

38. The “Articulator Wars”
“It was the best of times. It was the worst of times.” It was a
time of discovery and enlightenment, and a time of discord and
conflict. No, it was not the 18th century French Revolution,
but the second and third decades of the 20th century, in the
world of “full and partial plate prosthetics.”
“ friendships and alliances were formed, but regretfully for
some, lifelong enemies were made. After all, there were ideas
to expound and defend, and sadly, egos to protect. Thus was
the character of the “Articulator Wars.”

39. The “Articulator Wars”
Vertical and lateral “rotation points”
of the mandible existed only as
“theoretical rotation centers” and
not actual anatomic structures
Emphasis on condylar guidance as
the major influence on occlusion.
Condylar school of articulation
Mandible rotates around a single
central radial axis with the axis being
located above and/or behind the
plane of occlusion
Only tooth contacts guiding the
mandible during mastication
Geometric school of articulation
“Tripod” principle – no restraining
condylar hinge
Positional relations of the mandible
were recorded by setting three
guides with “check-bites.”
Positional school of articulation

40. The “Articulator Wars”

41. ‘ Geometric school ’
•Trend setting and created controversy
•Mandible rotates around a single central radial axis
with the axis being located above and/or behind the
plane of occlusion
•Arbitrary ; single rotation centre articulators
‘ One size fits all ’
No Balkwill-Bennet
movement
Credibility of the term ?....

42. Balkwill-Bonwill theory
4”
4”
BONWILL 1864
“Articulation of the teeth guides the mandible during function,
but that the centers of the condyles are also the centers of
lateral rotation for the mandible’s opening and
closing movements ”

43. •Average Value
4”
4”

44. •Average Value

46. The Spherical Theory: Should the Credit Go to
Christensen or Monson?
Studies on displacement path of the jaws.
“Total visible contact of the molar masticatory surfaces lies on
the same arc of a circle. The posterior continuation of this arc
touches the most anterior point of the condyle.
The location of the axis of that cylinder’s curvature is at the
level of the horizontal mid-orbital plane. ”

47. ‘Bite movement ’ should be in conformity with ‘ bite path ’
Almost-plane surface with an infinite
radius to a highly curved surface with a
radius of 4 to 5 inches.
Only a spherical surface arrangement of the occlusal plane
would allow continuous tooth contact during all excursions of
the mandible
Christensen only studied movement
in sagittal plane as described by
Spee whereas spherical motion is
multidirectional

48. Monson’s Spherical Theory
and Articulator

49. Mandibular teeth move over the occlusal surfaces of
the maxillary teeth, as over the external surface of a
segment of an 8-inch sphere, and that the radius (or
common center) of the sphere is located in the region
of the crista galli.

50. Maxillomandibular instrument

51. THE HAGMAN BALANCER
Based on spherical theory of
occlusion
Central hinge
No facebow or interocclusal records

52. THE STANBERY TRIPOD INSTRUMENT
•Reproduces positions & not movements.
•3 individual turrets & slots of the tripod, with the slots
forming a straight line to centric position.
•If the vertical dimension of occlusion is altered new
records must be made & the casts remounted.
‘ Positional ’ articulators

53. THE HOMER RELATOR
3 cups filled with
plastic
material
Tripoded upper member

54. The Appearance
and Early Use of the Incisal-pin and Guide
•‘Vertical Stop’ – a constant feature of articulators
since 1840s
•Short, vertical pin or screw contacting a fixed or
adjustable horizontal plate centrally located just
anterior or posterior to the condylar axis.

55. First decade of 20 century : Evolution of incisal pin as a
mechanism for controlling anterior guidance
Variable design depending on the inventor’s interpretation
of its intent !
Flat horizontal surface
Protrusive path with fixed /
adjustable lateral wings
Convex,concave,parabolic

56. C E Luce in 1911 : First patent ; First ‘scribing’ instrument
Ernest Eltner in 1912 : Chevron-shaped blade tip.
Horizontal guide table with adjustable
vertical flange to limit protrusive movement

57. Gysi ‘Adaptable’ articulator

58. Burch articulator
Acme articulator

59. David Shaw 1916
Chevron blade tip incisal pin
Curved insical guide wire
Hall ar
ticulators

60. Hall’s ‘
Dental Occluding Frame ’
FIRST PATENTED ‘CONTROLLING’ INCISAL GUIDE MECHANISM

61. Pursuing the Evolution of the Incisal-Pin and Guide
Trubyte Articulator: Gysi’s
“Improved Adaptable
Gysi coined the term ‘ Gothic Arch ’
Character of incisor
point movements in
the horizontal plane
The distance of the lateral rotation points of the mandible
from the sagittal plane could be determined by measuring
and tracing the paths of the incisor point

62. •The Needles-House intraoral chew-in or other positional records
•The lateral condylar guidance is controlled by the Bennett guide
•The incisal guide table can control horizontal & vertical
movement.
THE HOUSE – NEEDLE ARTICULATOR

63. THE WADSWORTH ARTICULATOR 1924
The casts were mounted with a face-bow & the Wadsworth T-
attachment, which determined a third point of reference.
•Adjustable intercondylar distance.
•Curvilinear condylar paths

64. The “Articulator Wars”
By 1920s -- utter confusion in the profession of ‘Plate Prosthesis ’
Concepts of mandibular function were varied and contradictory !
“It was essentially an engineering problem, and those trying to
solve it were not engineers.”

I
t was at this time that Rudolph L. Hanau came to the rescue.

65. Rudolph Hanau . One man one company !
Hanau = ‘ articulator’
In association with Dr Fredrick Stanton – Hanau-Stanton surveyor
1920 Dr Rupert Hall approached Hanau to devise adjustable three-dimensional
instrument with a central vertical axis, around which the condyles orbited during
function
‘Articulator Wars’ in early 20 century
“Shall we adjust an articulator to conform to the anatomical . . .
Requirements (of the patient), or may we expect our patients to fit an
average articulator?
Model A Model B Model C

66. Model
H
Model K
Kinoscope

67. L = H/8 + 12
….‘ Security Blanket’
‘ Resilient and Like Effect ‘

68. THE HANAU MODEL M KINOSCOPE

69. THE HANAU MODEL H110

70. THE PHILLIPS STUDENT ARTICULATOR
•The Phillips graphic recorder was designed to trace
in one step the Gothic arch (needlepoint tracing) &
the inclinations of the glenoid fossa.

71. THE PRECISION COORDINATOR
Curvilinear condylar guides Parabolic anterior cams
Curved incisal pin Milling device

72. THE FOURNET ARTICULATOR
Cook’s jig

73. THE DENTATUS ARL ARTICULATOR
It is a semiadjustable articulator.
An adjustable positioning mechanism

74. THE VERTICULATOR
•Consists of two rigid members that separate & close only
linearly in the vertical dimension.
•It has a positive stop & locks in its closed position.

75. THE NEY ARTICULATOR

76. THE SIMULATOR

77. DENAR MODEL D4A ARTICULATOR
Pneumatically controlled pantograph

78. Classifications:
1. Gillis (1926)
i) adaptable or adjustable
ii) average or fixed type
2. Bouchers (1934)
i) Non- adjustable
ii) Adjustable - a) 2 dimensional instrument
b) 3 dimensional instrument

79. 3. Kingery (1934)
i) Simple articulators
ii) Adjustable or adaptable
4. Beck (1962)
i) Suspension instrument
ii) Axis instrument
iii) Tripod instrument

80. 5. Weinberg (1963)
i) Arbitrary (monson spherical theory)
ii) Positional (stansbery tripod concept)
iii) Semiadjustable (Hanau H concept)
iv) Fully adjustable (Hanau kino scope concept, Gysi trubyte
concept, MC collum concept)
6. Posselt (1968)
i) plain line
ii) mean value
iii) adjustable

81. 7. Sharry(1974)
i) simple
ii) hinge type
iii) fixed guided
iv) adjustable

8.Heartwell and Rahn
i)Instrument that will receive & reproduce pantographs & graphic tracing
in three planes
ii)Instruments that will not receive pantograph
a) hinge type
b) arbitrary
c) adjustable (average)
d) Special- instrument designed to used for CD construction.

82. 9. Thomas (1973)
i) arbitrary (non – adjustable)
ii) positional (axis to non - axis type, static records)
iii) functional (axis to non-axis type, functional
records)
10.Based on Theories of Occlusion
1) Bonwill theory of occlusion

83. 2)Conical theory of occlusion:.
e.g. hall automatic articulator

84. 3) Spherical theory of occlusion – by
G.S.Monson(1918):
e.g. Maxillo mandibular instrument

85. 11. Based on Instrument Function
•At international prosthodontic workshop on
complete denture occlusion at University of
Michigan (1972)
1) Class I
•Simple holding instruments capable of accepting
a single static registration
•Vertical motion may or may not be possible
•E.g. hinge joint articulator, Barn door hinge.

87. 2) Class II
•Instrument that permits horizontal as well as
vertical motion but don't orient the motion to
TMJ via a face- bow transfer.
a) Class II A
•Permits eccentric motion based on average or
arbitrary values.
•E.g. Grittman articulator, simplex –by Alfred gysi

88. b) Class II B
•Permits eccentric motion based on arbitrary
theories of motion.
•e.g. maxillo – mandibular instrument by monson
c) Class II C
•Permits eccentric motion based on engraved
records obtained from the patient.
•E.g. House articulator by M M House (1927)
adjusted by means of needle- House chew in
technique.

90. 3) Class III
• Instruments that simulate condylar pathways by using
average or mechanical equivalents for all or part of the
motion. They allow for joint orientation of the casts via a
face bow transfer.
a) Class III A
•Accept static protrusive registration and use equivalents
for the rest of the motion.
•e.g. Hanau Model-Rudolp Hanau (1923) horizontal condylar
inclinations are set by means of instruments records.

92. b) Class III B
•Instruments in this class accept face bow transfer,
protrusive interocclusal records & some lateral
interocclusal records.
•E.g. Trubyte articulator – Gysi, Kino scope –Hanau,
tripod type – stansberry, Ney articulator – De Pietro.

94. 4) Class IV
•Accepts three dimensional dynamic registrations.
They allow for joint orientation of casts via a face
- bow transfer.
a) Class IVA
•The cams representing the condylar paths are
formed by registrations engraved by the patient.
•Do not allow for discriminating capability.
•E.g. TMJ instrument, Denar D4

96. b) Class IV-B
•Instruments that have condylar that can be angled &
customized either by selection from a variety of
curvatures, by modification, or both.
•E.g. Gnathoscope - Charles Stuart, Simulator – Ernest
Granger, Granger Gnatholator

99. 12. According to Bergstorm
1. Arcon
•Type of articulator that contains the condylar path
elements within its upper members while the
condyle is within the lower member.
•Can be semi-adjustable or fully adjustable.

101. 2. Non-arcon
•Type of articulator that contains the condyle as
part of the upper member while the condylar
path elements are in the lower member.
•Opposite set-up to naturally occurring anatomy

103. Hanau H 2 articulator series
•Non arcon instrument
•Fixed inter-condylar distance 110 mm
•Accepts a facebow record
•4 different facebows records accepted
•Horizontal condylar inclinations set by protrusive
interocclusal record
•Bennett angle calculated ???....
•Adjustable mechanical incisal guide table

105. Hanau H 2 articulator series

107. Hanau H 2 articulator series

108. Hanau H 2 articulator series

109. Hanau Wide Vue articulator series
•Arcon instrument
•Fixed intercondylar distance – 110 mm
•Open track / closed track
•Does not accept kinematic facebow transfer
•Adjustable ‘foot’ incisal pin with 3 types of incisal guide table

110. Condylar shaft
Centric lock
Adjustable incisal guide
table
Thumb nut
Thumb screw

111. Hanau Wide Vue articulator series

112. Hanau Wide Vue articulator series

113. Hanau Wide Vue articulator series

114. Whipmix articulator series

115. Whipmix articulator series

118. DENAR 5A
•Has total capacity to reproduce all
mandibular movements or jaw positions
recorded by any check bite or chew in
technique or by employing pantograph.
•Composed of maxillary & mandibular
bow with condylar elements in the
mandibular bow.
•Superior & medial fossa wall inserts are
available in straight forms or in various
curvatures in nylon or acrylic.

119. •When using pantographic tracing, the
acrylic inserts must be custom ground
with stone or bur.
•An adjustable metal incisal table & a
custom incisal platform are available.
Self curing acrylic resin can be used to
modify the platform.

124. Occlusal plane and cuspal inclination in relation to
Incisal-Condylar guidance for protrusive excursions
Attempt to relate the physiologic guidances with the laws of
conventional mechanics

125. Extreme guiding factors – Condylar guidance and Incisal guidance
– individual guidances !
Orientation of occlusal plane + mesiodistal
cuspal inclines ??? …
Mesiodistal cuspal inclines oriented on an
occlusal plane produce 1 guiding factor –
harmonized with Condylar and Incisal
guidances

126. Inverse ratio between mesiodistal cusp inclines and
orientation of occlusal plane !...

128. Can we reduce the occlusal forces acting on
residual ridges by reducing mesiodistal cusp
inclinations ?
Resultant vector of forces in the same direction

129. Changing the patient from..
‘ one occlusal plane to another ’
…
Full mouth rehabilitation --- steep occlusal plane
Reducing incisal guidance – occlusal harmony in
protrusive movements !
Dangerous
!

132. Muscular complex .. TMJ .. Teeth …
Which is the primary controlling factor ?..
Movement of solid body must have 3 points of guidance
Infinite number of physiologic factors produce coordinates of
mandibular movement
Laboratory objective : depend on mechanical principle to imitate
a resultant physiologic motion
Movement without tooth contact Incisal guidance and jaw motions

133. “ motion of the body of the mandible can vary by merely
changing anterior point of guidance and keeping other 2 at the
same path of motion ”
“.. Change in the contour of anterior guide path does not
necessarily affect condylar path ”
Cohen
Coordinated motion produced by muscle complex can be ‘measured’ at one point !

134. Incisal guidance in relation to jaw movements
When teeth are in contact they exert a strong influence
on entire physiologic system
Teeth -- mechanically advantageous position !!!

135. Clinical extrapolations….
Complete denture patients --- flatten incisal guidance
Fixed prosthodontics !

136. Laws of Articulation
1.Horizontal condyle inclination
2.Protrusive incisal guidance
3.Buccolingual inclination of tooth axes
4.Saggittal condylar pathway
5.Sagittal incisal guidance
6.Tooth alignment
7. The prominence of compensating curve
8. Inclination of the plane of orientation
9. Height of the cusps.
Believed articulation of teeth was related to 9 factors

138. Laws of articulation – Trapazzano’s concept
To analyze and reappraise ‘ Hanau’s Quint ’
Hanau’s study was a pioneer exploration ; ‘monument’ to him
“ Hanau was an engineer and could not be expected to
be well versed with biologic requirements which would
modify engineering requirements ”
Condylar inclination
“ The inclination of the condylar guidance or condylar
inclination is a definite anatomic conception ”
1.Bony contour
2.Action of muscles
3.Limitations of movements of ligaments
4.Method used
5.Realeff

139. “ One of the three most important and necessary
factors and forms one of the end controlling factors ”
Incisal guidance
“ The inclination of the incisal guidance is given by the
angle of the lingual surface of the incisors with the
horizontal plane of reference ”
-- Lingual surface of maxillary or mandibular incisors ?
-- True only when incisal edge / part of the labial surface
of mandibular incisors were in contact ….
Protrusive Lateral ….???

140. Sagittal protrusive incisal guidance : angle formed with the
horizontal plane by drawing a line in the sagittal plane between
the incisal edges of maxillary and mandibular central incisors
when the teeth are in centric occlusion.
GPT

141. Ridge relationship
Arch shape Ridge fullness
Inter-ridge space Esthetics
Phonetics

142. Lateral incisal guide angle : steepest angle formed
with the horizontal plane by drawing a line between
the incisal edges of maxillary and mandibular
incisors and cuspids of both right and left segments
when the teeth are in centric occlusion
“ One of the three important and necessary factors and
forms second of the end controlling factors ”

143. Height of the cusps
-- Misleading -- Led to misunderstanding
“ The change in the cusp height in comparison with masticatory
surface formation as a whole is an auxiliary magnitude ”
Part of Quint ?
“ In the establishment of balanced articulation we are
primarily interested in the length and inclination of
effective cusp inclines ”

144. Cusp angle is the third and the last factor that needs to
be considered in establishing a balanced articulation

145. Plane of orientation
Hanau is vague in discussing the plane of orientation and
needlessly complicating in considering it as a factor in
promulgating the laws of articulation .
‘Plane of Orientation ’ …. ???
‘Orientation of the Plane ’
‘ Plane of orientation is a purely geometric factor !.. 3 dental
landmarks
Inclination of plane of orientation = CG and IG
But …

146. Highly variable location within the available inter-ridge space
Should not be considered as a factor of laws of articulation
Deleted !

147. Prominence of compensating curves
The prominence of compensating curves infers an
increase of the concavity in the alignment of
mandibular posterior teeth…
Redundant as once a balanced occlusion is established
with a cuspal angulation , a compensating curve of varying
concavity is utilized
Deleted !

149. Discussion of ‘Laws of articulation’ – Boucher’s concept
‘Articulation’
‘ Occlusion ’
Quint : a device for showing that a number of factors are inter-related
Quint was developed with an assumption…
Alteration of any 1 factor
Alteration of other factors
required to re-establish balance
Trapozzano concept : Simpler and practical but not precise !
2 posterior factors3 anterior factors

150. Discussion of ‘Laws of articulation’
Condylar Guidance : considered to be unalterable !
But, facebow error : 16 mm high or low
Incisal Guidance : Not largely under the control of the
dentist
Orientation of occlusal plane : position of anterior teeth
forms the plane anteriorly
Plane not positioned to favour weaker ridge
For healthy soft tissues – plane at the same level as in natural
dentition
Compensating curve : permits an alteration of cusp height
without changing the form

151. Discussion of ‘Laws of articulation’
Cusp height : confusing factor !
Tooth tilted or cuspal incline changed by grinding

152. Lott’s concept

153. Levin’s concept

154. ARCON Vs NON ARCON
ARTICULATORS

155. ARCON Vs NON ARCON
ARTICULATORS
Condition found physiologically where the TMJ are located in
the skull and condyles are a part of the mandible
Relationship between the condylar slot and maxillary arch
remains constant !
More accurate reproductions of mandibular movements
obtainable
Fewer factors affect the setting of guide paths
No specific superiority in clinical evaluation of dentures made on
both articulators
Beck et al jpd
1959

156. ARCON Vs NON ARCON
ARTICULATORS
Both produce the same motion as condylar guidance is the
result of interaction of a condylar ball on an inclined plane
Reversing it did not change the guidance produced
Weinberg JPD 1963
A comparitive evaluation of discrepancy in condylar guidance
values between two commercially available arcon and non arcon
articulators
Dr Mukesh Goyal 2009 Manipal

157. Eccentric movement articulator and
non eccentric movement articulator
Approach to the occlusal position
To minimise adjustments and preserve anatomic
details

158. Factors of articulation
Immutable factors Mutable factors
1.Centric relation position
2.Hinge axis
3.Bennett movement
4.Condylar path
1.Axis orbital plane
2.Plane of occlusion
3.Curve of spee
4.Curve of wilson
5.Anterior guidance
6.Vertical dimension

159. Selection of articulators

160. In complete denture therapy …
Celenza : accurate centric relation a must but precise 3
dimensional registrations are a waste due to ‘ Realeff ’
Winkler : Non balanced occlusion with only stable centric
contacts – minimal requirements
Balanced occlusion – additional requirements
necessary
Boucher

161. In complete denture therapy …
Type of records desired

162. Semi- adjustable articulators – most desired one !
Once a shortcoming -- now an advantage !..
‘ Check-bite articulators ’
Straight line condylar paths – built in safety factor
Convex protrusive pathConcave orbiting path
Can be set without the need for any check-bites
Customized anterior
guidance
Simplified fossa
contour technique

163. Accuracy of recording condylar axis and vertical
dimension
Vertical dimension… to increase or not to increase ??? …
Minimal changes in VD – significant effect on tooth contact

165. Accuracy of recording condylar axis and vertical
dimension
Vertical dimension… to increase or not to increase ??? …
Minimal changes in VD – significant effect on tooth contact
Lower arch travels forwards on its closing arc – wider part
in contact with narrower part of upper arch
Equal intensity , simultaneous contacts of all teeth
without requiring displacement of TMJ

166. Conclusion
“ Prevention is better than cure ”