Brief description on Articulators for UG students.

1. ARTICULATION
CREATED BY: Dr. Joel Koshy Joseph MDS

2. Articulator:
A mechanical device which represents the
temporomandibular joints and the jaw members to which
maxillary and mandibular casts may be attached to simulate
jaw movements. (GPT 8)

3. Articulation
The static and dynamic contact relationship between the
occlusal surfaces of the teeth during function.

4. Occlusion:
The static relationship between the incising or masticating
surfaces of the maxillary or mandibular teeth or tooth
analogs. (GPT 8)

5. Functions of Articulators:
1. Hold maxillary and mandibular cast in a planned position.
2. Simulate TMJ and maxilla and mandibular movements (Similar to
patient).
3. To arrange artificial teeth.
4. Mounted models can be used for Diagnostic, treatment planning and
patient presentation.

6. Advantages of Articulators:
1. Provide a better view of the patient’s occlusion, especially the lingual
side.
2. Refinement of complete denture occlusion is extremely difficult
intraorally, because of movement of denture base and resiliency of
the supporting tissues.
3. Patient cooperation is not a factor, chairside and appointment time
for the patient is reduced.

7. Limitation of articulators:
1. Like all instruments, articulators are also
subjected to errors in tooling and errors resulting
from metal fatigue and wear.
2. No articulator can exactly duplicate the condylar
movements of an individuals
3. It can not compensate for any errors in jaw
relation records.

8. Classification of Articulations
• Based on adjustability
Non Adjustable Semi Adjustable Full Adjustable

9. Non Adjustable articulator:
An articulator that does not allow adjustment to replicate mandibular
movements.
Eg. Class I and II articulators,
Slab Articulators
Hinge articulators.
Mean Value articulator

10. Semi Adjustable:
An articulator that allows adjustment to replicate average mandibular
movements – also called Class III articulator.

11. Fully Adjustable Articulators:
An articulator that allows replication of three dimensional
movement of recorded mandibular motions. – Also called
Class IV articulators

12. • Based on position of condylar element:
1. Arcon: 2. Non - Arcon
Articulator Condyle

13. Based on instrument function:
Given by University of Michigan in 1972:
Aka: Michigan’s classification
Class I
Simple holding instrument capable of accepting a single static registration
vertical motion is possible. ( Open and Close movement)
Eg.
Slab Articulators Hinge Articulators
By J. B Gariot in 1805

14. Class II:
• An instrument that permits horizontal as well as vertical
motion but does not orient the motion to
temporomandibular joints.
• Horizontal and vertical movements can be done but can not
be adjusted.
• Average Values and theories are used.
Class IIA
Eccentric motions permitted
are based on average values.
Eg Grittman articulator, Gysi
articulator, Mean Value
articulator

15. Class IIB
• Eccentric motions permitted
are based on arbitrary theories
of motion.
• Spherical Theory
Each cusp and incisal edge
touches or conforms to a
segment of the surface of a
sphere 8 inch in diameter with its
centre in the region of glabella.
Eg. Maxillomandibular
instrument

16. Class IIB
• Eccentric motions permitted
are based on arbitrary theories
of motion.
• Bonwill theory
It states that distance between
the condyles and each condyle
and incisal point is 4 inch forming
a equilateral triangle.
Eg. Bonwill articulator

17. Class IIB
• Eccentric motions permitted
are based on arbitrary theories
of motion.
• Conical theory
It states that the lower teeth
move over the surfaces of the
upper teeth as over the surface
of a cone, generating an angle of
45 degrees with the central axis
of the cone tipped 45 degrees to
the occlusal plane. The teeth of
the maxillary denture would
conform to a segment of the
inner surface of an 8-inch cone.
Eg. Hall articulator

18. Class IIC
• Eccentric motions permitted
are based on engraved records
obtained from the patient.
Eg. House articulator by M. M
House 1927.
Used records obtained form
Centric record by the Needle
House method.

19. Class III
An instrument that stimulates condylar pathways by using
averages or mechanical equivalents for all or part of the
motion; these instruments allow for orientation of the casts
relative to the joints and may be acron or non-acron
instruments.
• Allow eccentric (protrusive and lateral).
• They accept facebow transfer.
• Eg. Semi adjustable articulators.

20. Class IIIA
Instruments accept only
protrusive record to adjust the
protrusive condylar inclinations.
Lateral condylar inclinations is
determined using Hanau
Formulae: L = H/8 + 12
Eg.: Hanau Model H and H2
Bregstrom.

21. Class IIIB
Instruments accept both
protrusive record and lateral
records to record condylar
inclinations.
Eg.:Hanau Kinoscope, Ney
articulator, Panadent

22. Class IV
An instrument that will accept three-dimensional dynamic
registrations; these instruments allow for orientation of the
casts to the temporomandibular joints and simulation of
mandibular movements.
• Fully adjustable articulators
• They accept facebow transfer
• All articulators are of Arcon
type with adjustable interco-
ndylar distance.

23. Class IVA
• The condylar pathways are
engraved by the patient
(Stereographic recordings) and
the instrument will accept
these three-dimensional
dynamic engravings.
• Eg.:TMJ articulator by Kenneth
Swanson 1965.
• Registration is obtained by
records generated by studs in a
cold cure resin (Similar to the
Needle House technique).
• Also known as Stereographic
recordings
• This recording is placed on the articulator and the condylar fossa
is moulded to produce an accurate replica of the patient’s TMJ

24. Class IVB
• The condylar pathways are
obtained using three-
dimensional tracings
(Pantographic recordings) and
the instruments will accept
these three-dimensional
dynamic tracings.
• Eg.: Denar D5A
There tracings are also available
in electronic forms as well.

25. Mean Value Articulator
• Class II A (Michigan Classification)
• Non-Adjustable Articulator (Based on Adjustability)
• Non- Arcon Articulator (Based on Condylar
position)
• Three Point Articulator
• Fixed horizontal axis
• Fixed incisal table angulation
• Fixed condylar path

26. Components:
a. Upper Member
b. Condylar shaft and slot
with spring
c. Lower Member
d. Support rod and
Orientation rod
e. Vertical support arms
f. Incisal adjustment screw
g. Incisal Rod
h. Incisal pin
i. Incisal Table

27. Functions:
1. Upper member: Holds the Maxillary cast
2. Condylar shaft and slot with spring: this represents the
condyle and glenoid fossa, angulated to 30 degree and
spring to push the condylar rod into position.
3. Lower member: holds the Mandibular cast

28. 4. Support rod: for stability for the articulator
Orientation Rod: for orientation of the occlusal
plane

29. Specifications:
Distance between the incisal and
condylar guidance: Average values
Inter-condylar distance: 110mm
Condylar Inclinations: 30 degree
Incisal table angulation: 5 degree

30. Incisal Rod:
• Maintains vertical height and
separation between the upper and
lower members and act as a vertical
anterior stop.
• Incisal pin: orientation of maxillary
anterior teeth
• Incisal Table: for anterior guidance
• Incisal Pin adjustment screw: to
change the position of incisal rod.

31. Procedure for articulations

34. Video on Mounting Cast on a mean valued
articulator

35. Video on transfer of Facebow to Hanau wide Vue II