This document discusses the determinants and factors of occlusion for complete dentures. It outlines 5 key determinants: 1) condylar guidance, 2) incisal guidance, 3) plane of occlusion, 4) compensating curve, and 5) cusp angle of teeth. Each determinant influences occlusion and mandibular movement. The document explains how to establish balanced occlusion by properly relating these 5 factors, such as minimizing incisal guidance to reduce harmful tipping forces. Developing occlusion requires considering these determinants and their interrelationships.

3. Dr. Amal Fathy Kaddah
Prof. of Prosthodontic,
Faculty of Oral & Dental Medicine,
Cairo University

5. Occlusion in complete denture
must be developed to function
efficiently and with the least
amount of trauma to the
supporting tissues.

6.  Preservation of the remaining tissues
 Proper masticatory efficiency
Enhancement of denture stability,
retention and support
 Enhancement of phonetics and
esthetics
Objectives

7. Anterior
determinants of
occlusion
Posterior determinants
of occlusion
The determinants of occlusion

8. 1. The condylar guidance
2. The incisal guidance
3. The inclination of plane
of occlusion
4. The compensating curve
and
5. cusp angle of teeth (Cuspal
inclination)

9. Rotation occurs when the mandible
makes a hinged movement. (the
head of the condyle rotates around
an imaginary axis)
Translation occurs when the
mandible moves into a protrusive or
lateral position, or a combination of
the two (bodily movement of the
head of the condyle)
The movements of the condyle in the
glenoid fossa are either:

10. No Translation
A- Rotation occurs when the head of the condyle
rotates around an imaginary axis

11. Translation
B. Translation is the bodily movement of the head of the condyle

12. The angle formed by the steepness of the
articulator surface of the Temporal bone as
related to a horizontal plane
The condylar guidance is the only factor
given by the patient
1- Condylar inclination

13. Condylar Guidance Angle
The angle formed by an
imaginary horizontal line
at the superior head of
the condyle and the path
that the condyle will
pass through during
function
Varies from individual to
individual because of
anatomical differences

14. 1. The shape of the glenoid
fossa.
2. The variation of the
thickness of the articular
disc in its different parts.
3. The relation of the
condyle to the disc during
movement.
4. The extent of mandibular
protrusion
The inclination of the condylar paths varies in
different individuals and from side to side in
the same person. It depends upon

15. Condylar path inclination varies according
to the amount of protrusion. a-b Sagittal condylar path
inclination. Centric relation position of the condyle.
4-P. 4 mm protrusion.8P. 8 mm protrusion

16. The condylar guidance: refers to the path
of the condyle follows in the temporomandibular
joint when the mandible moves into protrusive or
lateral movements
Balancing side.
Condyle has downward path
Working side.
Condyle pivots.

17. Bennett Angle
The angle formed by the
sagittal plane (assumed
straight protrusive path)
and the path of the
advancing (orbiting)
condyle during lateral
mandibular movements
as viewed in the
horizontal plane.
Balancing side. Working side.

18. • Working side: (Mandible moving toward
the cheek)
• Balancing side: (Mandible moving
toward the tongue)
• Working side condyle pivots within the
socket and is better supported.
• Balancing side condyle has a downward
orbiting path. It is traveling a greater
distance in ‘space’ and is more prone to
injury or damage.

19. If the condylar angle is
steep, its difficult to
produce balance occlusion
because when the condyle
travel downward and
forward; large space is
created posteriorly when
the anterior teeth are edge
to edge. So, compensation
should be made by altering
the other factors to obtain
the desired balance.

20. Means that when the patient produce a
protrusion with well adapted occlusal rims,
there will be a v- shaped gap between the rims
in the molar region.
Sagittal Christensen phenomenon

21. Means that when the patient
produce a lateral excurtion
with well adapted occlusal
rims, there will be a v shaped
gap between the rims in the
molar region on the balance
side. On the working side
there will be contact between
the upper and the lower rims.
The Transversal Christensen
phenomenon

22.  Ease of determination
 Used to set condylar
guidance
 Helps setting teeth
for best occlusal
contacts
Protrusive Records
To Set Condylar Inclination

23. Protrusive Records
To Set Condylar Inclination
 Material must interdigitate
with the opposing “V-
shaped” notches
 Record should cover entire
rim surface.
 Condylar elements are released from hinge
position (unlocked).
 Instrument protruded, and the rims closed into
record

24. Horizontal condylar guidance

25. Prior to Mounting
• Ensure
– Only wax-rim to wax-rim
contact
– Casts should not contact
– Record bases should not
contact
– If other contacts, mounting will
be incorrect

26. Adjust Protrusive Guide for
Maximal Interdigitation

27. The C.G. of articulator is an appropriated duplication of
the C.G. in the patient and is obtained by means of a
protrusive record. So that the patient's
temporomandibular joint is in harmony with the
occlusion as programmed on the articulator

28. The occlusion rims are reestablished and checked for 3mm.
Clearance in a protrusive excursion

32. After protrusive record
making the same procedure is
followed, however the patient
is asked to move his mandible
to left and right and getting
Right and left lateral relation
him to bite on wax wafer, two records are made, one
for left and one for right. These records are used to
adjust the lateral condylar inclination.

33. In Hauau
articulator
Hanan equation
can be used
L = H/ 8+ I2

36. It is the path taken by the
lower anterior teeth as it move
in protrusive movements
against the palatal surface of
upper anteriors till become
edge to edge.
2-The incisal guidance
It’s the influence of the contacting surfaces
of the mandibular & maxillary anterior teeth
on mandibular movement

37. The influence of
the contacting
surfaces of the
guide pin and
The incisal guidance of the
articulator
guide table on articular
movement.

38. Relation
between the
incisal path of
patient and
incisal
guidance of
articulator

39. Average incisal angle is about 10-20 degree
Average incisal angle is about 25-30 degree

40. Incisal Guidance Angle
The angle formed by the
intersection of the plane of
occlusion and a line within
the sagittal plane
determined by the incisal
edges of the maxillary and
mandibular central incisors
when the teeth are in
maximum intercuspation
HO

41. The incisal inclination is
called the incisal guide
angle and the influence that
this angle has on mandibular
movements is termed
incisal guidance.

42. Incisal Guidance Angle
This angle varies directly with the
vertical overbite and inversely with
the horizontal overjet
This angle is set to 10˚ in CD and
not exceeding 20˚

43. ↓ Incisal Guidance Angle
by either:
↑ Horizontal overlap
↓ Vertical overlap
Incisal Guidance

44. The incisal guide angle can be controlled when
developing a balanced occlusion. With a given amount of
vertical overlap (VO) the incisal guide angle can be made
flatter by increasing the horizontal overlap (HO)

45. It can also be made less steep by reducing VO
A- Steep incisal guidance
B. Medium incisal guidance
C. Zero incisal guidance
B

46. Incisal Guidance
• For CD, the incisal
guidance should be as
shallow as esthetics
and phonetics
will Permit when arrangement of anterior teeth
to reduce protrusive displacing forces

47. A) The esthetic factor dictated a steep vertical
overlap with little horizontal overlap. Therefore,
steeper posterior cuspal inclines had to be selected.
(B) In eccentric movements the inclinations of the
posterior cusps must be sufficient to prevent
anterior interference

48. A- The esthetic factors allowed for an adequate
amount of horizontal overlap, so the shallow
cuspal inclines could be selected.
B- In eccentric movement the shallow
posterior inclines are sufficient to prevent
anterior interference

50. I.G. should be either equal to or less than C.G.
I.G. SHOULD NEVER BE GREATER THAN C.G.

51. Anterior interference
I.G. GREATER THAN C.G
X

52. Excursive Movements
Centric
occlusion
Protrusive
The mandible moves essentially forward and the occlusal
contacts are smooth and simultaneous in the posterior both on
right and left sides and on the anterior teeth.

53. Excursive Movements
Centric
occlusion
Protrusive
Anterior interference

54. •I.G. can be set by the dentist
according to esthetics and
phonetics requirements.
but in no case should
I.G. exceed that
of the C.G.

55. If Increased Incisal
Guidance Angle For CD?
During protrusion:
Upper denture drops at
the back
Lower denture slides
backward

56. • Steep I.G. calls for steep cusps,
steep O.P. or a steep C.C. to effect an
occlusal balance.
• This type of occlusion is detrimental
to the stability and equilibrium of the
denture base.
Steep I.G. results in harmful inclined
planes with their harmful risk to the
supporting tissues

57. O. P. is formed by
lines connecting
tips of incisor
teeth and
distobuccal cusps
of the most
posterior teeth on
each side of arch
3- The Plane of Occlusion
(Plane of Orientations)

58. Effect Of Bonvill’s equilateral Triangle
theory On Complete Dentures
The construction of
average articulators is
generally in accordance
with Bonwill’s theory, and
Monson’s pyramid is based
also on Bonwill’s triangle.
This theory proposed that teeth move in relation
to each other as guided by the condylar controls
and the incisal point.
Christensen (1959)

59. The occlusal plane is
parallel to the ear
nose plane
The occlusal plane is
parallel to the
interpupillary line
3- The Plane of Occlusion

60. Its inclination can be altered slightly to a maximum of 10o
It is usually parallel to
Camper’s line.
It is not as important as
other factors
• Imaginary line from incisal
• edge of central incisal – DB cusp of 2nd molar
• Parallel to ala-targus line/Camper’s line
• Tilting of the plane >10 degree is not advisable
3- The Plane of Occlusion
(Plane of Orientations)

61. 1- Aesthetic base
2- Functional base (chewing and speech)
3- Physical and mechanical (leverage
action and parallelism).
Factors must be considered:
Determination of the occlusal plane

62. O.P. At (a) is the ala-
tragus plane obtained
from the patient. At
(b) is a compromise
plane midway
between ridges. At (c)
is a low plane
necessary to favor
weak lower ridges

63. •The orientation of the occlusal plane
becomes a fixed factor of occlusion
•Any necessary alteration for balancing
the occlusion must therefore be made
on other factors affecting the occlusion
(that is, the cuspal inclination or the
prominence of the compensating curve)
3- The Plane of Occlusion

64. Effect of plane of occlusion on cusp height

65. Effective Cusp angle
When we select a tooth with a certain cusp height or angle, it
doesn’t mean anything until the tooth is positioned in the
denture. For example, a particular tooth may be manufactured
with a 20 degree inclination. However, by tilting the tooth in
relation to the mean occlusal plane, one may create an effective
inclination of greater or less than 20 degrees.
CA
20o
CA
20o
Tilt
5o
Tilt
5o
5o Angle of O. plane
Plane of occlusion
horizontal
ECA 25o ECA 25o
• CA: Cusp Angle
• ECA: Effective Cusp angle
= CA 20o+ Angle of plane of
occlusion (5o) = (25o)

66. 4- Compensating curves
Importance of compensatory curves of
the dental arches (Curved Occlusal
Planes) for the natural dentition:
Guidance for the mandible Movement
to complement the paths of the
condyles for balance of the mandible

67. 4- Compensating curves
Artificial curves introduced into
complete denture are among the most
important determinants in establishing
a balanced occlusion so that the
occlusal surface results in a curve that
is in harmony with the movement of the
mandible as guided posteriorly by the
condylar path

68. 1- Spee’s curve
The anatomic curvature of the occlusal alignment of the
lower teeth beginning at the tip of the lower cuspid and
following the buccal cusps of the natural bicuspids and
molars continuing to the anterior border of the ramus
5- Compensating curves

69. The buccal cusps of the
lower posterior teeth are
slightly higher than the
lingual cusps, and a line
drawn through the buccal
and lingual cusps of the
teeth on the other side
forms a lateral curve
called the curve of Wilson
2- Wilson’s curve

70. A proposed ideal curve of occlusion..
the curve of occlusion in which each cusp and
incisal edge of upper and lower teeth of right and
left sides touches or conforms to a segment of the
surface of a sphere eight inches in diameter its
center in the region of the Glabella
3- Monson’s curve

71. Curve of Monson:
• It is a combination of curve of
Spee and the curve of Wilson.
• Coronal and sagittal planes.
• Concave for the mandibular
arch and convex for the
maxillary arch.
• in centric occlusion form a
segment of a sphere of 4 inches
radius with the center of the
sphere at the glabella

72. The compensating curve of the
artificial occlusion corresponds
to a combination of these curves
in natural teeth.
It is considered one of the most
important factors in establishing
balanced occlusion

73. Compensating Curves
• The steepness of the curve necessary to
achieve balance is the result of guiding
influence of angle of condylar guidance and
angle of incisal guidance.
• A lesser compensating curve for the same
condylar guidance would result in a steeper
incisal guidance (anterior interference),
which would cause loss of molar balancing
contacts.

74. Compensating Curves
• It is functionally and mechanically
advantageous to keep
compensating curve as modest as
possible → This is accomplished by
setting as shallow an incisal
guidance as phonetics, esthetics
permit

75. It is measured by the
angle formed by the
mesiobuccal cuspal
incline to the
horizontal plan when
the long axis of the
tooth is vertical to
the plane
Cusp Angle
4- Cusp Height (inclination of cuspless
teeth)

76. A steep condylar guidance necessitates teeth with steep cusps.
Cusp height is therefore an important determinant as it modifies
the effect of occlusal plane and compensating curves.

79. • Steep I.G. calls for steep cusps, steep O.P. or a
steep C.C. to effect an occlusal balance. The
angle of this movement is governed by the
cusp angles and hence the lower incisors will
move at the same angle as the lower molars

80. Cusp Angle

81. Hanau in 1926 formulated laws of balanced
articulation (called Hanau’s quint).
Hanau’s articulation Quint
Arrow pointing
away from center
indicates increasing
values
Arrow pointing
toward center
indicates decreasing
values

82. C= Condylar Inclination x Incisal Guidance
Occ. Plane x Cuspal Inclination x Comp. Curve
Hanau’s Quint
• The five factors of balanced occlusion related to one
another on a balance beam.
• To keep the occlusion in balance is a simple procedure
once the factors are related this way
• Within the confines of esthetics and phonetics, minimize
Incisal Guidance in Complete Dentures to minimize
inclined tipping forces
(1926)

83. Condylar
guidance
Incisal
guidance
Occlusal
Plane
Cusp
Height
Compensating
curve
Theilmann’s Formula
The five factors of balanced occlusion related
to one another on a balance beam. To keep the
occlusion in balance is a simple procedure
once the factors are related to this way

84. Condylar
guidance
Incisal
guidance
Occlusal
Plane
Cusp
Height
Compensating
curve
Theilmann’s Formula
* The incisal guidance and inclination of the plane of
occlusion: can be altered within a small range according
to esthetic and phonetic and anatomical factors.

85. As the mandible is protruded its position is
controlled by the incisal guidance and the
condylar path. The center elements
affecting balance, namely the plane of
occlusion, the cusp inclines, and the
compensating curve, can be adjusted to
harmonize. Their relationship to one
another is easily recognized if this diagram
is reproduced as a cutout for actual
manipulation.

94. The dentist can only control four
of five factors
* The condylar guidance: can be completely fixed
and is not his to change.
* The incisal guidance and inclination of the plane of
occlusion: can be altered within a small range
according to esthetic and physiologic
(phonetic)and anatomical factors.
* Cusps on the teeth and tooth inclination of
cuspless teeth and compensating curve: are the
real working tools of balanced occlusion.

95. • Steep I.G. calls for steep cusps,
steep O.P. or a steep C.C. to effect an
occlusal balance.
• This type of occlusion is detrimental
to the stability and equilibrium of the
denture base.
Steep I.G. results in harmful inclined
planes with their harmful risk to the
supporting tissues
According To The Formula

96. • To achieve balanced occlusion: For
high condylar guidance we need to
have high compensating curve,
occlusal plane and cuspal height.
• To achieve balanced occlusion: For
high incisal guidance we need to have
high compensating curve, occlusal
plane and cuspal height.
According To The Formula

97. To achieve balanced occlusion, the steeper
the condylar guidance, the greater the cusp
height toward the posterior
or the steeper the compensating curves
According To The Formula
CG+IG EFFECT OF OP.CC. CH. BALANCED OCCLUSION SCALE BALANCED OCCLUSION SCALE
CG x IG OP XCC X CH

98. To achieve balanced
occlusion, the steeper the
compensating curves,
the less the cusp height toward
the posterior
According To The Formula

99. Bilateral Balanced Lingualized Occlusion
Protrusive
Balancing Side
Working Side
Centric Occlusion

100. Two figures with the same condylar inclination but
different incisal guide inclinations. A, Steep vertical
overlap, with resultant steep cusp inclines. B, Less
incisal angle, with resultant flatter cusp inclines
a b

101. Two figures with different condylar inclinations and different incisal
guide inclinations. a, Less condylar inclination with flatter cusp
inclines, with resultant Steep vertical overlap. b, Steep condylar
inclination with steep cusp inclines or Steepen the compensating
curves with resultant Less incisal angle.
b
a
The condylar guidance has great influence in the second
molar region and progressively less till the incisor region.
X

102. Point O is the intersection
point for the
perpendiculars dropped
from the condylar &
incisal guidance plane.
It is the radius for the
occlusal plane & cusp
inclines to establish
balanced occlusion.
If the incisal guidance is steeper than the condylar
guidance than balanced occlusion is not possible

103. Question
Q) Suppose that the incisal guidance is set and the
condylar guidance is steeper than your chosen 20 degree
teeth. To obtain balanced occlusion in your complete
denture, what should you do?
a. Steepen the compensating curves in both sagittal and
frontal planes
b. Steepen the compensating curves in only sagittal but
not frontal plane
c. Decrease the inclination of occlusal plane
d. Decrease the steepness of compensating curves in
both sagittal and frontal planes
e. Steepen the condylar guidance
f. None of the above

104. Concepts of
Occlusion for
complete denture
Next lecture

105. Everything is okay in the
end
If it's not okay, then it's
not the end