Factors affecting balanced occlusion and its effects on denture stability

1. 1
Balanced occlusion
Dr. veena Saraf

2. 2
Occlusion
• The static relationship between the incising or
masticating surfaces of the maxillary or
mandibular teeth or tooth analogues (GPT 8)
Articulation
• The static and dynamic contact relationship
between the occlusal surfaces of the teeth during
function (GPT 8)

3. 3
Balanced Articulation
• The bilateral, simultaneous, anterior, and posterior
occlusal contact of teeth in centric and eccentric
positions (GPT 8)

4. 4
Balanced occlusion
• “Balanced occlusion in complete denture can be
defined as stable simultaneous contact of the
opposing upper and lower tooth in centric relation
position and a continuous smooth bilateral gliding
from this position to any eccentric position within
normal range of mandibular function”. (Winkler)

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DIFFERENCES BETWEEN NATURAL AND
ARTIFICIAL OCCLUSION
 Natural teeth
 Natural teeth function
independently and each
individual tooth disperses
the occlusal load.
 Malocclusion can be non-
problematic for a long
time
 Artificial teeth
 Artificial teeth function
as a group and the
occlusal loads are not
individually managed.
 Malocclusions problems

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Natural teeth
 Non-vertical forces are
well tolerated
 Incising does not affect
the posterior teeth.
 The second molar is the
favored area for heavy
mastication for better
leverage and power.
Artificial teeth
 Non-vertical forces
damage the supporting
tissues
 Incising will lift the
posterior part of the
denture.
 Heavy mastication over
the second molar can tilt
or shift the denture base.

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Natural teeth
 Bilateral balance is not
necessary and is usually
considered a hindrance
 Proprioceptive impulses
give feedback to avoid
occlusal prematurities.
This helps the patient to
have a habitual occlusion
away from centric
relation.
Artificial teeth
 Bilateral balance is
mandatory to produce
stability of the denture.
 There is no feedback and
the denture rests in
centric relation. Any
prematurities in this
position can shift the
base.

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REQUIREMENTS OF
COMPLETE DENTURE OCCLUSION
Stability of occlusion at centric relation position
& in area forward & lateral to it
Balanced occlusal contacts (tripod contact) during
all eccentric movements.
Unlocking the cusps mesiodistally to allow for
gradual but inevitable settling of the bases due to
tissue deformation & bone resorption.

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The control of the horizontal force by
buccolingual cusp height reduction .
Functional lever balance by favorable tooth to
ridge crest position

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REQUIREMENTS OF
COMPLETE DENTURE OCCLUSION….
Cutting, penetrating and shearing efficiency of
occlusal surface
Incisal clearance during posterior functions like
chewing.

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REQUIREMENTS OF
COMPLETE DENTURE OCCLUSION….
Minimum occlusal contact areas for reduced
pressure in comminuting food
Sharp ridges or cusps and generous sluice ways to
shear & shred food with minimum of force
necessary.

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Types of balance or equilibrium
• Unilateral balance
- Unilateral lever balance
- Unilateral occlusal balance
• Bilateral balance
- Bilateral occlusal balance
- Protrusive occlusal balance

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Unilateral lever balance
• Equilibrium of the base on its supporting
structures , when a bolus of food is interposed
between the teeth on one side & a space exists
between the teeth on the apposite side

14. 14
Unilateral lever balance…..
• Placing the teeth so that the resultant direction of
force on the working side is over the ridge or
slightly lingual to it
• Wide area of coverage
• Placing the teeth as close to the ridge as possible
• Using a narrow buccolingual width occlusal food
table as possible

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Unilateral occlusal balance
• Occlusal surfaces of the teeth one side articulate
simultaneously , as a group ,with a smooth
uninterrupted glide

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Bilateral occlusal balance
• Equilibrium on both sides of the denture due to
simultaneous contact of teeth in centric &
eccentric occlusion
• Minimum of three contacts to achieve equilibrium

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Bilateral occlusal balance
• Incisal guidance
• The plane of occlusion
• The angulation of teeth (tilt & inclination)
• The cusp angulation
• The compensating curve
• Inclination of the condylar path

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Protrusive occlusal balance
• When the mandible moves essentially forward and
the occlusal contacts are smooth and simultaneous
in the posterior both on right & left sides and on
the anterior teeth

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Considerations
• The tooth size & position in relation to the ridge
size & shape
• The extent of denture base coverage
• Occclusal balance with stable contacts at the
retruded border position & in an area anterior to
it

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Considerations……
• Right & left eccentric occlusal balance by
simultaneous contacts at the limit of functional
& Para functional activity
• Intermediate occlusal balance for all positions
between centric occlusion and all other functional
& Para functional excursions

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Is balanced occlusion is
needed ????

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Is “Balance” Necessary?
• Tests of Balanced and Non-balanced Occlusion
• Trapozzano
• 1) No patient preference
• 2) Balanced = slightly more efficient
• 3) Percentage of patients using eccentric
movements during mastication is small
JPD 10: 476-487, 1960.

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• Bilateral balanced contact during the terminal arc
of closer help to seat the denture in a stable
position –lever balance.
• Swallowing saliva
• Closing to reseat the denture
• Clenching

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Advantages of bilateral balance
• Better masticatory efficiency
• Better stability of denture base
• Reduced trauma, improved comfort
• The functional movements are possible

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Concepts Proposed to Attain
Balanced Occlusion:
• Gysi’s Concept(1914):
• Arranging 330 anatomic teeth could be used under
various movements of the articulator to enhance
the stability of the denture.

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French’s concept (1954):
• Lowering the lower occlusal plane to increase the
stability of the dentures along with balanced
occlusion.
• He arranged upper first premolars with 50
inclination, upper second premolars with 100
inclination and upper molars with 150 inclination.

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Sears’s concept:
• He proposed balanced occlusion for non-
anatomical teeth using posterior balancing ramps
or an occlusal plane which curves
anteroposteriorly and laterally.
JPD 1958 ;8; 776

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Pleasure’s concept:
• Pleasure introduced a pleasure curve or the posterior
reverse lateral curve to align and arrange the posterior
teeth in order to increase the stability of the denture.
• He used nonanatomic tooth forms & sets the premolars
&first molars in an anti-Monson curve , thus the pressure
transmitted through the bolus to such an incline creates a
resultant force which eliminates the possibility of buccal
tipping & thus seats the denture
• 1st premolar & 1st molar are set in AntiMonsons curve
• 2nd molar in Monson curve ,this combination is pleasure
curve

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Frush’s Concept:
• He advised arranging teeth in a one-dimensional
contact relationship, which should be reshaped
during try-in to obtain balanced occlusion.

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Hanau's Laws of Articulation
And The Quint
(1) Horizontal Condyle Inclination,
(2) Compensating Curve,
(3) Protrusive Incisal Guidance,
(4) Plane Of Orientation,
(5) Buccolingual Inclination Of Tooth Axes,
(6) Sagittal Condylar Pathway,
(7) Sagittal Incisal Guidance,
(8) Tooth Alignment, and
(9) Relative Cusp Height.
A reevaluation of Hanau's Laws of Articulation and the Hanau Quint
JPD 1978;3;254

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Hanau's Quint
(1) Condylar Guidance,
(2) Compensating Curve,
(3) Relative Cusp Height,
(4) Incisal Guidance, and
(5) Plane Of Orientation.

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Trapozzano Concept
• He eliminated the plane of orientation "since its
location is highly variable within the available
inner ridge space.
• He also suggested that the occlusal plane can be
located at various heights to favor a weaker ridge.

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Trapozzano’s Triad of Occlusion,

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Boucher Concept
(1) there are three fixed factors: the orientation of
the occlusal plane, the incisal guidance, and the
condylar guidance;
(2) the angulation of the cusp is more important than
the height of the cusp; and
(3) the compensating curve enables one to increase
the effective height of the cusps without changing
the form of the teeth.

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THE LOTT CONCEPT
1. The greater the angle of the condyle path, the
greater is the posterior separation.
2. The greater the angle of the overbite (vertical
overlap), the greater is the separation in the
anterior region and the posterior region
regardless of the angle of the condyle path.

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3. The greater the separation of the posterior teeth, the
greater, or higher, must be the compensation curve.
4. Posterior separation beyond the ability of a compensation
curve to balance the occlusion requires the introduction
of the plane of orientation.
5. The greater the separation of the teeth, the greater must
be the height of the cusps of the posterior teeth.

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39. 39
Bernard Levin’s concept
• Eliminate the plane of orientation.
1. The condylar guidance is fixed and is recorded
from the patient.
The balancing condylar guidance includes the
working condyle Bennett movement, which may or
may not affect lateral balance.

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2.The incisal guidance is usually obtained from the
patient's esthetic and phonetic requirements.
However, it can be modified for special requirements,
e.g., a reduction of the incisal guidance is
considered to be helpful when the residual ridges
are flat

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3. The compensating curve is the most important
factor for obtaining balance. Monoplane or low
Cusp teeth must employ the use of a compensating
curve.

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4. Cusp teeth have the inclines necessary for
obtaining balanced occlusion but nearly always
are used with a compensating curve.

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The Quad

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References
• Boucher’s Prosthodontic Treatment for
Edentulous Patient”, 12th edition, Zarb-
Bolender.
• Boucher’s Prosthodontic Treatment for
Edentulous Patient”, 10th edition, Zarb-
Bolender, Hickey, Carlsson.
• Essentials of Complete Denture Prosthodotics,
2nd Edition, Sheldon-Winkler.

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References ………..
• Complete Denture Prosthodontics – Swenson.
• Text Book of Complete Dentures, 5th edition,
Rahn, Charles Heartwell.
• Complete Denture Prosthodontics – Sharry.
• Clinical dental prosthetics, H.R.B.Fenn,
K.P.Liddelow , A.P.Gimson

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References ………..
• Journal of Prosthetic Dentistry 1957; 8: 776
• Journal of Prosthetic Dentistry 1978; 39 : 484
• British Dental Journal 1997; 128:1140.
• Journal of Prosthetic Dentistry 2000; 84(4):390
• Journal of Prosthetic Dentistry 2001; 85(1):15-19.

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