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COMPLETE DENTURE
OCCLUSION
Balanced Occlusion
and Articulation
Dr. Monia MN Kandil
Bilateral simultaneous occlusal contact of
teeth, anteriorly and posteriorly, in both
centric and eccentric positions.
Gliding of the teeth across each other
during their movement from one position to
another, without any interferences.
1- Provide maximum denture stability during
functional and parafunctional movements of the
mandible.
2- Help in distribution of the masticatory pressure
over the supporting tissues and reduce trauma to
the underlying tissues.
3- Increased efficiency of mastication.
4- Psychologically it is more comfortable to the
patients who enjoy comfort and satisfaction only
when eccentric balance is present.
1- Balance in centric
achieving  Stable
and physiologic
occlusion.
stability of complete dentures are well
served by the freedom in centric (long
centric) concept
2- Balance in eccentric Occl.
During lateral excursions:
There should be working and balancing side contacts, or
At least There a minimum of three-point contact
between the lower centrals and posterior teeth on each
side.
Teeth make contact in lateral excursion
on the working and balancing sides
Excursive Movements
Laterotrusive and Mediotrusive
LEFT MANDIBULAR EXCURSION
Non-working Side
(Mediotrusive)
Working Side
(Laterotrusive)
2- Balance in eccentric Occl.
During protrosive excursions:
It should be at least three-point contact between the
teeth on each arch one anterior and 2 posteriors.
If with anatomic teeth
arrangments  follow
compensating curves.
If with non-anatomic teeth, should use
for example:
Tilting the second molar 
 Using balancing rump
Reverse curve of Wilson 
Factors affecting occlusal balance
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
A, Inclination of the
condylar guidance.
B, Prominence of the
compensating curve
C, Plane of orientation
D, Height of the cusp
E, Inclination of the I.G
The movements of the condyle
in the glenoid fossa are either
translation or rotation
Translation occurs when the
mandible moves into a protrusive or
lateral position, or a combination of the
two
Rotation occurs when the mandible
makes a hinged movement.
No Translation
A- Rotation occurs when the head of the
condyle rotates around an imaginary axis
Translation
B. Translation is the bodily movement of the head of the condyle
A- Rotation occurs when the head of the
condyle rotates around an imaginary axis
B. Translation is the bodily movement of the
head of the condyle
1. The condylar guidance
The condylar guidance: refers to the path of
the condyle follows in the temporomandibular joint
when the mandible moves into protrusive or lateral
movements
Condylar inclination is the angle formed by the steepness
of the articular surface of the temporal bone as related to a
horizontal line.
The inclination of the condylar
paths varies in different individuals
and from side to side in the same
person. It depends upon
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 condylar guidance is the only
factor given by the patient.
Bennett Angle
• The angle formed by the
sagittal plane (assumed
straight protrusive path)
and the path of the
advancing
(orbiting)
condyle during lateral
mandibular , when the
movements as viewed in
the horizontal plane.
The Condyler guidance (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
2-The incisal guidance
The incisal guidance
It is the path taken by
the lower anterior teeth
as it move in a
protrusive movements
against the palatal
surface of upper
anteriors, till become
edge to edge.
The incisal angle
A) Anatomically: 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
Incisal guide
angle:
B) On an articulator:
That angle formed in
the sagittal plane,
between the plane of
reference and the slope
of the anterior guide
table, as viewed in the
sagittal plane
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)
B
A. Steep incisal guidance
B. Medium incisal guidance
C. Zero incisal guidance
It can also be made less steep
by reducing VO
Inc.G should be either equal to or less than Condy.G.
Inc.G should not never be greater than Cndy. G.
Inc.G. can be set by the dentist
according to esthetics and
phonetics requirements.
Steep I.G. calls for steep cusps,
steep O.P. or a steep C.C. to effect
an occlusal balance.
This type of occlusion results in
harmful inclined planes with their
harmful risk to the supporting
tissues
More controllable
Condylar
guidance
Incisal
guidance
Occlusal
Plane
Cusp Compensating
Height
curve
3- The Plane of Occlusion
(Plane of Orientations)
Occl. P. is an
imaginary plane
formed by lines
connecting tips
of incisor teeth
and disto-buccal
cusps of the
most posterior
teeth on each
side of arch
Anterior and Posterior occlusal plane
Parallel to interpupillary line.
Parallel to the ala tragus line.
Occl.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
The Plane of Occlusion
•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)
Determination of the occlusal plane
Factors must be considered:
1- Aesthetic base
2- Functional base (chewing and speech)
3- Physical and mechanical (leverage
action and parallelism).
Determination of the occlusal plane
Aesthetic base.
• The Height Of Occlusal Plane
Should Be 1-2 Mm. Below The
Upper Lip.
Anteriorly Is Influenced By:
• The Length Of The Lip,
• Ridge Fullness,
• Ridge Height, The Amount
Of The Maxillomandibular
Space And
• The Incisal Guide Angle.
Functional base (chewing and speech)
Chewing
• The height of occlusal plane should be convenient and
at a level familiar to the tongue to perform its action
easily and stop food escaping to the floor of the mouth.
• The occlusal surface of the
teeth should be below the
greatest convexity of the
tongue.
•
This also improves the
stability of lower denture.
Functional base (chewing and speech)
Speech:
• During speech, the tongue pushes against
the sides of the teeth to produce a seal for
better pronunciation of words.
Principle of Physics and
Mechanics
1) Leverage action
2) Parallelism
3) Arch form
The amount of leverage or torque exerted on the occlusal plane
is a function of the height of the plane above the ridge.
Torque X = force (f) x Distance from fulcrum (R).
Principle of Physics and
Mechanics
1) Leverage action:
• The nearer the occlusal plane to
the basal bone of the jaws, the
less the leverage action and the
better the stability.
Principle of Physics and
Mechanics
2) Parallellism:
• The occlusal plane should be parallel to both
supporting ridges. In this way the biting forces
are vertical on the ridges and there is no tendency
for horizontal displacement of the dentures
.
Effect of occlusal plane orientation on denture
stability
Principle of Physics and
Mechanics
3) Arch form
Both the width of the occluding surfaces and the
contour of the arch form of the occlusion rims should
be individually established to simulate the desired
arch form of artificial teeth
4- Compensating curves
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
2- Wilson’s curve
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
3- Monson’s curve
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
The compensating curve of
the artificial occlusion
corresponds to a
combination of these
curves in natural teeth. It
is considered one of the
more important factors in
establishing balanced
occlusion
4- Cusp Height (cuspal inclines of
tooth and inclination of
cuspless teeth)
Cusp Angle
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
Types of posterior teeth
1- Anatomic teeth
2- Modified or semianatomic
tooth
3- Non-anatomic tooth
Anatomic teeth
Simulate the natural tooth form.
It has cusp height of varying
degrees of inclination that will
intercuspate with an opposing
tooth of anatomic form.
The standard anatomic tooth has
inclines of approximately 33o
Nonanatomic
tooth
Problems with anatomic teeth
1- The presence of cusp inclines can cause
trauma, discomfort and
instability to the bases because
of the horizontal component of force that
produced during function.
2- The use of adjustable articulator is
mandatory.
3- Various eccentric records must be made
for articulator adjustments.
4- Harmonious balanced occlusion
lost when settling occurs.
is
5- The bases need prompt and frequent
relining to keep the occlusion stable and
balanced.
6- Mesiodistal interlocking will not permit settling of
the base without horizontal force
developing. That acting on thin delicate mucosa
and the underlying bone creates
shearing that are not well tolerated
The arrows indicate the direction and the
magnitude of the force generated by the
two types of teeth as they penetrate the
bolus of food during masticatory cycle
Sharp cusped teeth need
less vertical force for
penetration but produce
more lateral force owing to
the inclined plane effect.
Flat teeth more vertical
force but produce less
lateral force components
Problems with non-anatomic tooth
1- Do not function efficiently
unless the occlusal surface provides
cutting ridges and spillways.
2- They can not be corrected by
occlusal grinding without impairing
their efficiency.
3- Appear
dull and unnatural.
Selection of tooth forms
is based on
1- The capacity of the ridges
2- Interridge distance
3- The ridge relationship
1- The capacity of the ridges
Strong well-formed
horizontal force
resist
2- Interridge distance
A large interridge distance creates a
long lever arm through which
horizontal forces created by the
inclines of cusps can act.
'Therefore, this force can be
controlled by using flat teeth as
the interridge distance increases.
A large interridge distance
3- The ridge relationship
Non-anatomic posterior teeth
used effectively to control the
forces of occlusion and to stabilize
the denture base supported by
compromised weak ridge in
either
class II or class III ridge
relationship
Classification of Relationship
Between Arches
•Skeletal
•Dental
•Posterior teeth
•Anterior teeth
•General rules
•Class 1 – mandibular only slightly back
•Class 2 – mandibular more backwards
•Class 3 – mandibular more forward
1) Lever balance
2) Occlusal balance
"Balanced Occlusion"
1- Lever balance
Dependent on tooth position
as related to its base
1. Placing the teeth over the
ridge or slightly lingual to it.
2. Denture base area covers as
wide area on the ridge as
possible.
3. Placing the teeth as close to
the ridge as other factors will
permit.
4. Using as narrow a
buccolingual width occlusal
food table.
2- Occlusal balance
"Balanced Occlusion"
Is dependent on tooth contact
"stable simultaneous contact of the
opposing upper and lower teeth in
centric relation position with a
continuous smooth bilateral gliding
from this position to any eccentric
position within the normal range of
mandibular function".
Bilateral balance in artificial teeth, is
necessary to stabilize the bases.
All five factors of balance interact with each
other, and changes in any one effect changes
in the others. for the final analysis, 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) factors.
* Cusps, on the teeth and tooth inclination of
cuspless teeth and compensating curve: are
the real working tools of balanced occlusion.