zTHE DENTAL ARTICULATOR.ppt

ARTICULATOR

1. THE DENTAL
ARTICULATOR
Dr. James Buckman

2. TO EVALUATE OCCLUSAL RELATIONSHIPS
CASTS HAVE TO BE ARTICULATED
•Some casts can be hand held in maximum intercuspation

3. TO EVALUATE OCCLUSAL RELATIONSHIPS
CASTS HAVE TO BE ARTICULATED
•Some casts have to be held in position mechanically
•In some cases we want to simulate mandibular
positions and movements more accurately than hand
articulating can accomplish

4. MOUNTED CASTS ARE A SIGNIFICANT
DIAGNOSTIC AID IN EVALUATING AND
PLANNING OCCLUSAL RELATIONSHIPS

5. NOT ONLY ARE ARTICULATORS OF DIAGNOSTIC
IMPORTANCE, THEY ARE NECESSARY TO CARRY
OUT TREATMENT PROCEDURES AS WELL
•Supporting the working casts to fabricate restorations
and simulating mandibular movement

7. ARTICULATOR:
•A mechanical instrument that represents
the temporomandibular joints and jaws, to
which maxillary and mandibular casts may
be attached to simulate some or all
mandibular movements. –GPT -8

8. TO UNDERSTAND THE ARTICULATOR,
WE NEED:
•An understanding of the specific
determinants of mandibular movements
*These factors will vary from patient to
patient which will result in different
patterns of movement
*Articulators are designed to have
these factors either fixed or
adjustable to simulate the mandibular
movement of each of our patients
•What the parts of the articulator simulate
anatomically and how they function
•Classification and capabilities
•How do we manipulate and adjust

9. DETERMINANTS OF MANDIBULAR
MOVEMENT
•Right TMJ
posterior determinants
•Left TMJ
•Incisal guidance or occlusion –anterior determinant -
programs the fourth determinant
•Neuromuscular response
Guichet

10. POSTERIOR DETERMINANTS OF
MANDIBULAR MOVEMENT
•Intercondylar distance
•Angle of articular eminence
•Immediate side shift
•Progressive side shift
•Bennett movement -forward/backward
•Bennett movement -up/down
ANTERIOR DETERMINANT OF
MANDIBLAR MOVEMENT
•Incisal guidance or occlusion –programs
the fourth determinant

11. INTERCONDYLAR DISTANCE
•The distance between the rotational centers
of two condyles or their analogues –GPT-8
•Distance between the vertical axes (in mm)
•ICD
ICD

12. ANGLE OF ARTICULAR EMINENCE

13. ANGLE OF ARTICULAR EMINENCE
•Measured in degrees from the horizontal

14. IMMEDIATE SIDE SHIFT (MLR)
•Measured in mm or tenths of mm from the
centric position of the condyle
ISS

15. PROGRESSIVE SIDE SHIFT (MLT)
•Measured in degrees from a sagittal plane
passing through the centric position of the
condyle or the termination of the immediate,
early, or distributed M.L.T. if present –
usually 6-8 degrees

16. BENNETT MOVEMENT ON WORKING
SIDE–BACKWARD OR FORWARD
•Measured in degrees from the frontal plane

17. BENNETT MOVEMENT ON WORKING
SIDE –UP OR DOWN
•Measured in degrees from the horizontal plane

18. INCISAL GUIDANCE
•Measured in degrees from the horizontal
plane

19. HOW DO THESE FACTORS EFFECT
THE OCCLUSAL SURFACES OF
RESTORATIONS
•Intercondylar distance
•Angle of articular eminence
•Immediate side shift
•Progressive side shift
•Bennett movement -forward/backward
•Bennett movement -up/down
•Incisal guidance

20. INTERCONDYLAR DISTANCE EFFECTS
The path the lower teeth follow during lateral
11movement
The direction of the grooves on the posterior
11teeth

21. INCISAL GUIDANCE OF 30˚; ANGLE OF ARTICULAR
EMINENCE OF 30˚ -MANDIBLE WILL FOLLOW A
30˚PATH IN A PROTRUSIVE MOVEMENT
Cusp height has to be less than 30˚or will have an
interference
30˚
45˚

22. POSTERIOR INTERFERENCE

23. THE LAST PATIENT HAD AN INCISAL
GUIDANCE OF 30˚ AND AN ANGLE OF
ARTICULAR EMINENCE OF 30˚

24. ANOTHER PATIENT MAY HAVE AN INCISAL
GUIDANCE OF 30˚ AND AN ANGLE OF
ARTICULAR EMINENCE OF 60˚
This patient can have longer cusps
because the mandible will separate more
posteriorly due to the steeper eminence
45˚

25. POSTERIOR DISCLUSION
(SEPARATION)

26. NOW LET’S LOOK AT ANOTHER PATIENT WHO
MAY HAVE AN INCISAL GUIDANCE OF 60˚ AND
AN ANGLE OF ARTICULAR EMINENCE OF 60˚
Cusps of the posterior teeth may be as
steep as 59˚ and still disclude because the
mandible is following a 60˚ path
60˚

27. GREATER DISCLUSION (SEPARATION)
OF POSTERIOR TEETH

28. DETERMINANTS OF MANDIBULAR
MOVEMENT
•Intercondylar distance
•Angle of articular eminence
•Immediate side shift
•Progressive side shift
•Bennett movement -forward/backward
•Bennett movement -up/down
•Incisal guidance
The other determinants and more specific effect on
the occlusal surfaces will be discussed later in the
course

29. What is important about these
factors:
•These factors will vary from patient to
patient and effect occlusal surfaces of the
teeth
•Articulators are designed to have these
factors either fixed or adjustable to
simulate the mandibular movement of
each of our patients

30. TO UNDERSTAND THE ARTICULATORS,
NEED:
•An understanding of the specific
determinants of mandibular movements
*These factors will vary from patient to
patient which will result in different
patterns of movement
*Articulators are designed to have
these factors either fixed or
adjustable to simulate the mandibular
movement of each of our patients
•What are the parts of the articulator and
what do they simulate anatomically
•Classification and capabilities
•How do we manipulate and adjust

33. •Medio-lateral position of the maxillary arch
•Medio-lateral cant of the maxillary arch
Maxillary cast positioned to articulator by
means of the face bow which transfers
the

34. •Anterior –posterior position of the maxillary arch
•Medio-lateral position of the maxillary arch
•Cant of the maxillary arch in relation to the sagittal
plane
Maxillary cast positioned to articulator by
means of the face bow which transfers the

35. •Anterior –posterior position of the maxillary arch
•Anterior –posterior cant of the maxillary arch or the
fossa occlusal plane angle (FOP angle)
Maxillary cast positioned to articulator by
means of the face bow which transfers
the
or the Balkwill Angle

36. Balkwill Angle : the angle formed by the Bonwill
triangle and the Balkwill triangleor the plane of occlusion –
incisors 35 mm below condyles and angle of 26°
Bonwill triangle: a 4 inch equilateral triangle
bounded by lines connecting the contacts of the
mandibular central incisor’s incisal edge to each condyle
and from one condyle to the other
35mm
26°

38. CRANIUM – UPPER MEMBER
Right and left fossae

39. FOSSA – FOSSA ELEMENT
•Condyles articulate with the fossa elements
on articulator similar to how the condyles
articulate with the fossae in the skull –
except on the articulator condyles touch all
three walls

40. TOP WALL
•On articulator simulates and functions as
the articular eminemce
•Referred to as the condylar guide
•Can be adjusted for different angles

41. Condyles move in a similar manner on
the articulator as they do in the skull
•Protrusive or balancing movement, the
condyle moves down and forward

42. BACK WALL
•Looks like the back wall of the fossa, but
retrodiscal tissue is between back wall
and condyle in patient
•On articulator functions as a mechanical
stop for the condyle

43. MEDIAL WALL
•Balancing side medial wall a factor in
determining the amount of M.L.T. or side
shift
CR Left Lateral

45. DETERMINANTS OF MANDIBULAR
MOVEMENT
•Intercondylar distance
•Angle of articular eminence
•Immediate side shift
•Progressive side shift
•Bennett movement -forward/backward
•Bennett movement -up/down
•Incisal guidance

46. INCISAL GUIDANCE AND CONDYLAR
GUIDANCE

47. INCISAL GUIDANCE AND CONDYLAR
GUIDANCE

48. INTERCONDYLAR DISTANCE

49. INTERCONDYLAR DISTANCE

50. INTERCONDYLAR DISTANCE

51. INTERCONDYLAR DISTANCE

52. INTERCONDYLAR DISTANCE

53. MANDIBULAR LATERAL TRANSLATION
Protrusive movement

54. PROTRUSIVE MOVEMENT

55. MANDIBULAR LATERAL TRANSLATION
Progressive Side ShiftBennett Movement

56. PROGRESSIVE SIDE SHIFT

57. PROGRESSIVE SIDE SHIFT
Bennett Movement
PSS

58. IMMEDIATE SIDE SHIFT
•Differs from progressive side shift as there is no
forward movement of the balancing side condyle

59. IMMEDIATE SIDE SHIFT
ISS
Bennett Movement

60. IMMEDIATE SIDE SHIFT
PSS
ISS
Bennett Movement

61. IMMEDIATE SIDE SHIFT

62. IMMEDIATE SIDE SHIFT

63. BENNETT MOVEMENT ON WORKING SIDE –BACKWARD OR FORWARD –ON
ARTICULATOR DETEMINED BY ANGLE OF BACK WALL ON WORKING SIDE

64. BENNETT MOVEMENT ON WORKING SIDE –UP OR DOWN –ON
ARTICULATOR DETEMINED BY ANGLE OF TOP WALL ON WORKING SIDE
•Downward,
more separation
•Upward, less
separation

65. TO UNDERSTAND THE ARTICULATORS,
NEED:
•An understanding of the specific
determinants of mandibular movements
*These factors will vary from patient to
patient which will result in different
patterns of movement
*Articulators are designed to have
these factors either fixed or
adjustable to simulate the mandibular
movement of each of our patients
•What are the parts of the articulator and
what do they simulate anatomically
•Classification and capabilities
•How do we manipulate and adjust

66. CLASSIFICATION OF ARTICULATORS BY:
•Location of condylar guides
Arcon –condylar guides are located on the
maxillary or upper member of the articulator
Nonarcon (condylar articulator) –condylar guides
are located on the mandibular or lower member of
the articulator
•Capabilities
Hinge
Fixed determinant
Semi-adjustable
Fully adjustable

67. NonarconArcon
Condylar guide remains a
constant angle to upper
member of articulator as
lower member opens and
closes
Condylar guide changes
its angulation as lower
member of articulator
opens and closes

68. TWO ALWAYS RULES –RULE ONE
•Always check to see that the fossae elements are
tight against the upper member of the articulator.
•Always keep the balancing side condyleagainst it’s
medial and top walls and the working side condyle
against it’s back and top walls when executing a
lateral movement.
balancing side condyle
medial and top walls
working side condyle
back and top walls

69. RULE TWO
•There should be no “play” between the
upper and lower members of the
articulator
•The lower member should travel back so
the condyles meet their respective back,
top, and medial walls with no pressure
being applied

70. CLASSIFICATION BY CAPABILITIES
•Hinge –only capable of opening and closing movements,
not capable of lateral or protrusive movements (Class I)
•Fixed determinant –(average value) capable of opening
and closing, lateral, and protrusive movements. All
determinants are set to average or mean values and not
adjustable. (Class II)
•Semi-adjustable –capable of opening and closing, lateral,
and protrusive movements. Some of the determinants can
be adjusted. (Class III)
•Fully adjustable –capable of opening and closing, lateral,
and protrusive movements. All determinants are
adjustable. (Class IV)

71. CLASSIFICATION: GPT -9
•Articulator: a mechanical instrument that represents the
temporomandibular joints and jaws, to which maxillary
and mandibular casts may be attached to simulate some or all
mandibular movements; Editorial note for usage: articulators are
divisible into four classes;
•Class I articulator: a simple holding instrument capable of
accepting a single static registration; vertical motion is possible;
syn, NONADJUSTABLE ARTICULATOR
•Class II articulator: an instrument that permits horizontal as well
as vertical motion but does not orient the motion to the
temporomandibular joints
•Class III articulator: an instrument that simulates 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 arcon or nonarcon
instruments; syn, SEMIADJUSTABLE ARTICULATOR
•Class IV articulator: an instrument that will accept 3D dynamic
registrations; these instruments allow for orientation of the casts
to the temporomandibular joints and simulation of mandibular
movements; syn, FULLY ADJUSTABLE ARTICULATOR, FULLY
ADJUSTABLE GNATHOLOGIC ARTICULATOR

72. HISTORICAL ARTICULATORS
•Gysi 1910
•Arcon or nonarcon?
•Fixed determinant or semi-adjustable?

73. HISTORICAL ARTICULATORS
•Gysi 1910
•Arconor nonarcon?
•Fixed determinantor semi-adjustable?

74. HISTORICAL ARTICULATORS
•Snow: 1910; first face bow
•Fixed determinant or semi-adjustable?
•What is adjustable?

75. HISTORICAL ARTICULATORS
•Snow: 1910; first face bow
•Fixed determinant or semi-adjustable?
•What is adjustable? Condylar guide
•Arcon or nonarcon?

76. HISTORICAL ARTICULATORS
•Snow: 1910; first face bow
•Fixed determinant or semi-adjustable?
•What is adjustable? Condylar guide
•Arconor nonarcon?

77. YOU HAVE RECEIVED:
•Whip mix -1964 –semi adjustable
•Adjustable condylar guide and progressive side
shift
•All other determinants are fixed

78. DIFFERENT FOSSAE ARE AVALABLE
WHICH HAVE:
•A fixed progressive side shift of 6-8˚
•An adjustable immediate side shift

79. RIGHT SIDE IMMEDIATE SIDE SHIFT

80. TWO ALWAYS RULES –RULE ONE
•Always check to see that the fossae elements are
tight against the upper member of the articulator.
•Always keep the balancing side condyleagainst it’s
medial and top walls and the working side condyle
against it’s back and top walls when executing a
lateral movement.
balancing side condyle
medial and top walls
working side condyle
back and top walls

81. RULE TWO
•There should be no “play” between the
upper and lower members of the
articulator
•The lower member should travel back so
the condyles meet their respective back,
top, and medial walls with no pressure
being applied

82. Thank You