occlusion of complete denture teeth.pptx

OCCLUSION
BY:prof. Dr. mahmoud

INTRODUCTION
 Occlusion is an anatomic and physiologic complex
present when the opposing teeth are in contact. It
consists of the positional relations, the stresses
directed to the supporting structures, their
resistance to stresses, the form and the
arrangement of the teeth , the influencing factors of
the components of the tempromandibular joints
(TMJ), and the neuromuscular mechanism
responsible for mandibular movements, the teeth,
their contacting surfaces and investing tissues
and/or the denture supporting structures.

DEFINITIONS
 Static occlusion :
static relationship between the occlusal surfaces of
the maxillary and mandibular teeth when they are
in contact and the jaws can be either centric or
eccentric relation. The static contacting of the teeth
should be differentiated from gliding occlusion.
Gliding “Dynamic” occlusion : is the contacting of
teeth in motion.Gliding occlusion occurs when the
occlusal surfaces of the teeth make contact when
the mandible is moving to and from eccentric and
centric jaw relations.

centric relation CR; a maxilla mandibular
relationship, independent of tooth contact, in which
the condyles articulate in the anterior-superior
position against the posterior slopes of the articular
eminences .it is a clinically useful, repeatable
reference position.(bone to bone).
centric occlusion : the occlusion of opposing teeth
when the mandible is in centric relation; this may or
may not coincide with the maximal intercuspal
position. (tooth to tooth).
occlusal balance : a condition in which there are
simultaneous contacts of opposing teeth or tooth
analogues on both sides of the opposing dental
arches during eccentric movements within the
functional range.

occlusal harmony : a condition in maximal
intercuspal position and eccentric jaw relation in
which there are no interceptive or deflective
contacts of occluding surfaces
occlusal interference:
1. Any tooth contact that inhibits the remaining
occluding surfaces from achieving stable and
harmonious contacts.
2. Any undesirable occlusal contact.
Maximal intercuspal: position the complete
intercuspation of the opposing teeth independent to
condylar position.
Mandibular movement can be: opening, closing,
protrusive, and lateral;
in lateral it may be
 Working side is the side that the mandible move
toward it in lateral excursion.
 Nonworking side is the side that the mandible
move away from during lateral excursion.

DIFFERENCE BETWEEN NATURAL AND
ARTIFICIAL TEETH
1.Fixed in bone
2.Supported by
periodontal ligament
3.Tooth move into
socket during
mastication because of
elasticity of ligament
4.When teeth , move
one side during
mastication the other
side is not affected
1.Rest on residual
ridge
2.not fixed to soft
tissue
3.Denture move
toward tissue because
of resiliency of mucosa
4.When teeth meet on
one side ,the other
side loses balance
upsetting retention
and stability
Natural teeth Artificial teeth

DIFFERENCE BETWEEN NATURAL AND
ARTIFICIAL TEETH
5. When teeth move in
socket, they produce
stretching effect and exert
tensile force
6. Tensile force
produce stimulation to
under lying bone
7. Physiologic
stimulation maintain
good health of the bone
8. To maintain the
stimulus optimal
occlusion of natural teeth
is important
5.Compression of soft tissue
causes displacement of the
supporting tissue
6.Compression causes
pressure on mucosa of
affecting vascular supply of
bone
7.Instability of denture
causes loss of bone because
of leverage
8.To maintain the
supporting tissue in good
health ,planed occlusion is
necessary
Natural teeth Artificial teeth

REQUIREMENT OF IDEAL COMPLETE
DENTURE OCCLUSION
1. Stability of occlusion in centric relation.
2. Balanced for all eccentric contacts bilaterally for all eccentric
mandibular movements.
3. Unlocking the cusp mesiodistally to allow for gradual but
inevitable settling of the bases due to tissue deformation and bone
resorption.
4. Control of horizontal forces by buccoligual cusp height reduction
according to the residual ridge resistance and interridge space.
5. Functional lever balance by favorable tooth to ridge crest
position
6. Cutting and shearing efficiency of the occlusal surface (sharp
cusps or ridges)
7. Anterior clearance of teeth during mastication.
8. Minimum occlusal contact between the upper and lower teeth to
reduce pressure during function (lingualized occlusion)

TYPES OF OCCLUSAL SCHEME:
As manufactured, posterior denture teeth exhibit
differing cusp angles and cusp heights.
Some have minimal or no cuspal angles and are called
non-anatomic teeth, while the cuspal angles of semi-
anatomic and anatomic teeth vary from approximately
10° to 45°.
The cusp angle is only accurate when the denture
tooth is placed so that the long axis of the tooth is
perpendicular to the plane of occlusion, if it is altered;
the cusp angle of the tooth relative to the occlusal
plane is also changed. This altered cusp angle has been
termed the effective cusp angle of the tooth (ECA).

1. ANATOMIC TEETH
 Simulate the natural teeth form with inclination
approximately 33 degree
 Advantages:
1. Esthetic.
2. Better food penetration.
3. Vertical stress decrease.
4. Harmony with TMJ and muscle of mastication.
5. Balance occlusion in eccentric position
 Disadvantages:
1. Precise technique requires.
2. More time.
3. Difficult teeth position in CL II &CL III& cross bite.
4. Greater lateral force.

2. SEMI ANATOMIC
 teeth cusp incline less steep than anatomical
teeth called modified anatomical teeth (less
than33⁰ “about 20 ⁰” ).
 Advantages:
1. Esthetic. 2. Good chewing efficacy.
3. Less lateral force.
4. Balance occlusion in centric.
 Disadvantages:
1. Less esthetic than anatomic .
2. Poor bolus penetration.
3. Cannot be balanced in eccentric excursions

3. NON ANATOMICAL TEETH)MONO PLANE,
CUSPLESS ,FLAT, NON CUSPAL, ZERO DEGREE)
 Flat and without cusp height.
 Advantages:
1.More applicable in all ridge relationship class II
& III due to there is no intercuspation.
2. Create minimal horizontal forces.
3. Easily maintenance of occlusion in complete
denture.
4. Fabrication of denture with simple technique
and simple articulator no need for adjustable
articulator.

 Disadvantages:
1.Decrease cutting efficiency.
2. Flat teeth occlude in 2 dimensions (Width &
Length) but mandible has 3-dimesions So, teeth
loss shearing efficiency
3. Vertical component present in mastication
doesn't provided.
4. Flat teeth are not function efficiency unless
occlusal surface provide cutting edges & slice ways.
5. They can't be corrected with occlusal grinding
without impairment their efficiency.

6. Flat teeth appear dull and unnatural to some
patient. So, create psychological problems.
7. Bilateral & protrusive movement are not
possible in purely flat occlusion. I.e. with
protrusion, there will be space posteriorly.
Balance occlusion for non-anatomic teeth may be
accomplish by:
1. Compensating curve.
2. Tilting the second molar.
3. Placing the balancing ramp.

CONCEPTS OF OCCLUSION
 Concepts in Centric occlusion:
A) Point centric.
B) Slide in centric.
C) Freedom of centric (long centric).
 Concepts in Eccentric occlusion:
A) Balanced.
B) Non-Balanced.

CENTRIC OCCLUSION
A. Point centric : This concept in which maximum
intercuspation coincide with centric relation.
It appears in 10-15 % in population.
There are 3 features of gnathologic concept of
articulation:
1.Point centric in centric.
2. Balanced occlusion in eccentric.
3. Free articulation → no interfere of cusps during
movement.

B. Slide in centric:
Definition: The 2 or 3-dimensional sliding movement that
mandible make as it moves from most retruded position
to inter cuspal position. (From centric relation to centric
occlusion-maximum intercuspation-).
It occurs due to wear of cusp, carious teeth or loss of
teeth→age changes.
It occurs in 90 % of population with natural dentition.
Centric occlusion in occlusal contacts that are stable
while centric relation in occlusal contact that are not
stable so,the sliding occurs from centric relation to
centric occlusion.
When the sliding movement is straight forward, it can be
tolerated by patient but if occur with lateral slide, it can't
be tolerated → TMJ or muscle problems.

C. Freedom of centric (long centric):
In this concept, there is freedom of movement of mandible
to close without interference into contact in centric
relation & in between (maximum intercuspation).
In this concept, there is flat area created between centric
relation & centric occlusion on the occlusal surface of the
teeth.
It's not presents in natural teeth but can be created by
occlusal adjustment to offer the patient a state he can
tolerate.
It also, can be done on artificial teeth in complete
denture.
When we use monoplane artificial teeth, the freedom of
centric present automatically.
The anterior teeth should arrange to allow this freedom of
movement.
Widening of central fossa → create freedom.

CONCEPTS OF OCCLUSION IN ECCENTRIC
POSITIONS:
 A. Balanced Occlusion (Balanced articulation):
 Definition: It's an occlusal relationship as many teeth
as possible are in occlusion & when changing from
one relation to another they move with smooth,
sliding motion free from cuspal interference and
maintenance even contact.
 It's generally produced by cusp formed teeth & need
definite arrangement of teeth to produce
simultaneous contact of all the posterior teeth in
harmony with the mandibular movement so providing
stabilization forces on the denture base on their basal
seat.
 Bilateral simultaneous contact of opposing teeth in
centric & eccentric (lateral & protrusive) positions.

FACTORS AFFECTING THE BALANCED
OCCLUSION (LAWS OF ARTICULATION HANAU
QUINT)
1. Condylar guidance
2. Incisal guidance
3. The occlusal plane
4. The compensatory curves
5. Cusp angulation

1. CONDYLAR GUIDANCE:
The path that the condyle will pass through during function.
Components of condylar guidance:
a. Horizontal condylar guidance: guides the forward movement
for protrusive balance.
b. Lateral condylar guidance: guides the sideward or lateral
movement of the mandible.
 The first factor of occlusion is the condylar guidance, this
factor recorded from the patient. So it is fixed factor cannot be
modified by the dentist.
 The steeper the condylar guidance, the more separation of the
teeth that will occur when the mandible moves in a protrusive
or lateral movement (Christensen’s phenomenon).
 So compensation large space created posteriorly should be
made by altering the other factors to obtain the desired
balance.

2. INCISAL GUIDANCE:
 Range from to 0-10
 0 for flat teeth.
 10 for cusp teeth.
 Its affect contact of upper & lower anterior teeth
on occlusal balance.
 If incisal guidance is steep, it result in' steep
cusps, steep occlusal plane (steep compensatory
curves) for stability.
 This type of occlusion lead to stability of
equilibrium of the denture base.

 In complete denture: the incisal guidance should be
flat as esthetic & phonetics will permit.
 But if arrangement of anterior teeth need vertical
overlap, compensatory horizontal overlap(over jet)
should be set to prevent the anterior interference on
occlusal balance of posterior teeth.
 In flat teeth: overbite must be zero (no incisal
guidance) (WHY?)
 As with no overbite and the patient protrude his
mandible, no space created posteriorly balanced
contact.
 To provide anteroposterior movement with
interlocking of anterior teeth.

3. PLANE OF OCCLUSION:
 Anteriorly: by the height of the lower cuspids
which is nearly coincident with the
commissures of the mouth.
 Posteriory: by the height the retromolar pad.
 It is also related to:
The ala-tragus line. Or
The camper's plane.
 Its position can be altered slightly without
creating serious functional problems.
 Its role is not as important as are the other
factors.

4. THE COMPENSATING CURVE:
the are introduced in the construction of complete
removable dental prostheses to compensate for the
opening influences produced by the condylar and
incisal guidance’s during lateral and protrusive
mandibular eccentric movements.
 Determined by
1. Inclination of posterior teeth
2. Their vertical relationship to occlusal plane.

THERE ARE TWO TYPES OF CURVES:
A). Anterioposterior compensating curve for Curve
of spee: Anatomic curvature of the occlusal
alignment of teeth beginning at the tip of lower
canine and following the buccal cusps of the
natural premolars and the molars, continuing to
the anterior border of the ramus”
as described by Graf Von Spee. When the patient
moves his mandible forward, the posterior teeth
set on this curve will continue to remain in
contact. Thus avoiding disocclusion.

B.) Lateral compensating curves:
Curve of Wilson: The curve, viewed from the front
that contacts the buccal and lingual cusps of the
molars, being lower in the middle due to the lingual
inclination of the long axes of the mandibular
molars.
Curve of Monson: The curve of occlusion in which
each cusp and incisal edge touches to a segment of a
sphere of 8 inches in diameter with its center located
at the glabella. It is a three dimensional curve. It
runs across the palatal and buccal cusps of maxillary
molars.

5. CUSPAL ANGULATIONS OR INCLINATION
OF CUSPLESS ARTIFICIAL TEETH
 It depends on several factors residual ridge,
neuromuscular control, esthetics, etc) however,
it’s better to reduce the cuspal inclination to help
reduce horizontal forces of occlusion.
 For the balanced occlusion, it is important to use
adjustable articulator

TYPES OF BALANCED OCCLUSION:
1 Unilateral Lever Balance.
2 Unilateral Balanced Occlusion.
3 Bilateral Balanced Occlusion.
4 Protrusive Balanced Occlusion.

1- UNILATERAL LEVER BALANCE:
This is present when there is equilibrium of the base
on its supporting structure.
When a bolus of food is interposed between the teeth
on one side & space exist between the teeth on the
opposite side → unbalanced occlusion.
This equilibrium is encouraged by the following:
1. Placing the teeth so that, resultant direction of
force on functioning side is over the ridge or
slightly lingual to it (without tongue crumpling).
2. Having the denture base cover as wide an area on
the bridge as possible (wide coverage of bone over
ridge as possible).
3. Using a narrow buccolingual width occlusal force
table as practical.

Decrease occlusal table:
1) Decrease Lateral force.
2) Decrease Force on the ridge.
3) ↑ Masticatory efficiency.
4) Placing the teeth as close to the ridge as other factors
will permit. I.e. decreasing of the vertical height.

2- UNILATERAL BALANCED OCCLUSION:
• It is occur when the Occlusal surface of the teeth
on one side articulate simultaneously as a group
with a smooth uninterrupted glide on the
balancing side.
• Unilateral balanced occlusion is a widely
accepted method of tooth arrangement in
restorative dentistry.
• Unilateral balanced occlusion calls for all teeth
on the working side to be in contact during
lateral excursion movement. On the other hand,
teeth on the non-working side are contoured to
be free of any contact.
• The function of the teeth on the working side is
distribute the occlusal load.

• The absence of contact on the non-working side
prevents these teeth form being subjected to the
destructive forces found in the non-working
interference as it also saves the centric holding
cusp.
• This concept mostly indicated in (crown & bridges
& natural teeth ) If not present , so there is
premature contact.
 Group function:
 In this concept, all the teeth on the working side
may be in contact or several teeth may be required
to contact thorough the lateral movement to
produce balance.

3- BILATERAL BALANCED OCCLUSION:
 Bilateral balanced occlusion is present when there is
equilibrium on both sides of the denture due to
simultaneous contact of the denture in centric &
eccentric occlusion.
 It requires a minimum of 3 contacts for establishing a
plane of equilibrium. The more contact, the more
assured the equilibrium.
 It dictates that, a maximum number of teeth should
contact in all excursive position of the mandible.
 This is particularly useful on complete denture
construction in which contact in the non-working side is
important to prevent tipping of the denture.
 This concept is very difficult to achieve in the artificial
occlusion: require adjustable articulator with lateral
and protrusive wafer.

Advantages:
Bilateral balanced contacts help to seat the denture in
a stable position during functional& parafunctional
activities.
 This type of balance is dependent on the interaction
of:
1) The incisal guidance.
2) The plane of occlusion.
3) The angulation of teeth (tilt & inclination).
4) The cusp angulation (height).
5) The compensating curves & the inclination of
condylar path.

4- PROTRUSIVE BALANCED OCCLUSION:
 This is present when the mandible moves
essentially forward & there are smooth &
simultaneous posterior occlusal contact on both
right & left sides and on the anterior teeth.
 These contacts are important to stabilize the
bases during incising & non-functional
activities.
 It is slightly different from bilateral balance in
that:
1) It requires a minimum of 3 contact, 1 on each
side & 1 anterior.
2) 2) It is dependent on the interaction of same
factors.

 The Criteria to accept the concepts of balanced
occlusion:
1. Maximal simultaneous bilateral contact in centric
position.
2. Working contacts present all along the working side.
3. Balancing contacts in protrusive position in the molar
region. This may require tipping the distal end of the
mandibular second molar up so that the mesiolingual
cusp of the maxillary second molar will contact the distal
marginal ridge of the mandibular second molar. If a
compensating curve is required to provide protrusive
balance, it can be created by tipping the mandibular
second bicuspid distally, depressing the mandibular first
molar, and placing an upward inclination on the
mandibular second molar.
4. For Balancing in the molar region in lateral position, one
contact is sufficient.
5. The occlusal plane of the completed setup parallel to the
maxillary and mandibular residual ridges.

CONCEPTS OF BALANCED OCCLUSION IN
ECCENTRIC POSITION

1 The gnathological concept.
2 The concept of buccal reduction of the lower
posterior.
3 Zero-degree teeth with curves. "French".
4 Zero-degree teeth with curves & ramps.
5 Zero-degree teeth with reverse lateral curve and a
ramp. "Wilson".
6 Flat teeth with Max pleasure scheme.
7 Linear Concept.
8 The lingualized occlusion.

1- THE GNATHOLOGICAL CONCEPT:
 In this concept, the anatomical & semi-
anatomical teeth are arranged in point centric &
incisal overlap for esthetic.
 During lateral & protrusive movements, bilateral
contact is present to prevent tipping or rotation
of denture.
 *Advantages of this concept:
1) Distribute the masticatory force over supporting
tissue.
2) Stability of denture.
3) Reduce trauma to underlying tissue.

2- THE CONCEPT OF BUCCAL REDUCTION
OF THE LOWER POSTERIOR:
 This concept is advocated by French who used semi-
anatomic teeth with buccal reduction of lower posterior
teeth resulting in reduction of occlusal table of lower
posterior teeth & movement of occlusal table lingually.
This result in stability of dentures.
 The upper & lower lingual cusps are in contact in centric
occlusion.
 The upper posterior teeth will have a very slight lingual
occlusal inclines. These are:
 5° for upper first premolar.
 10° for upper second premolar.
 15° for upper first & second molars.
 So that, a balanced occlusion will be developed laterally
& anteroposteriorly (1st & 2nd molars) by arranging the
teeth on curved occlusal plane (compensatory curves)

 Reduction of the buccal cusp. Reduced to be away
from contact &the upper posterior teeth is oblique
lingually to have a balance laterally. So, there is
contact in the balanced side & in working side.
 Briefly:
• Contact between upper palatal & lower lingual
cusp > balanced occlusion & lever balance.
• Upper teeth have very slight inclines (5°, 10° &
15°) so that when patient occlude on one side, there
is simultaneous contact on other side > balanced
occlusion laterally.

3- ZERO-DEGREE TEETH WITH CURVES:
(MONOPLANE TEETH)
 Aim:
Arranging flat teeth on compensatory curves, which
determined by chew-in teeth technique to prevent
space created posteriorly while protrusion (christen
phenomenon).
 Advantages:
1) They are more adopted to a common jaw relations.
2) More easily used in cross-bite situations.
3) Import the patient a sense of freedom because they
don't lock the mandible in one position only.
4) They eliminate horizontal forces that may be more
damaging than vertical forces.
5) No need for adjustable articulator.

 Zero-degree teeth can be set on lateral &
anteroposterior curves harmonies with the condylar
inclination to attain reasonable balancing contact in
lateral & protrusive positions.
 One of the weakness of the monoplane teeth, is that
because of the Christensen effect, heavy pressure is
exerted on the anterior segment in protrusion.
 Setting the artificial teeth on a curve solves this
problem (compensatory curves).
 With zero-degree teeth, it is necessary to use a zero-
degree incisal guidance (zero overbite) to develop
balancing contacts in the protrusive position.
 We can produce horizontal over jet for esthetic but
without overbite.

 How to produce curves?
The chew-in or Paterson technique should be
used for determining compensating curve on which
the teeth will be arranged, the use of arbitrary
compensating is undesirable (should be functional
from the patient itself). Therefore, we get
functionally generated path.
 Notes:
 If ↑ incisal angle → the cusp angle will be ↑.
 If not or use flat teeth, there will be space & free of
contact in protrusion & denture will not be stable.
 So, in using flat teeth-> use over jet but not
overbite.

CHEW-IN TEETH TECHNIQUE: (PATERSON
TECHNIQUE)
 Construct a stable acrylic denture base with
compound rim.
 Determine the vertical dimension, then transfer
this relation to simple articulator.
 Make ditch (groove) in the rim & fill it with a
plaster pumice (abrasive material) mixture
(1/2:1/2)
 The upper & lower rims must be higher than the
actual vertical by23 mm
 Leave the rims to be set, then give it to the
patient and instruct him to make excursive
movements15-30 mints> To grind in the plaster
pumice rim to the proper vertical dimension.

 Draw & transfer a curve of the condylar path into the
occlusal rim. Thus forming a functionally generated
path.
 The functionally generated path of the patient is
used to set the flat teeth on this curve.
 Thus, the flat teeth then can be set with Monson's &
Spee's-like compensatory curves.

4- FLAT OR ZERO-DEGREE TEETH WITH
CURVES & RAMPS:
 It is not always possible to arrange cuspless teeth
in balanced occlusion with compensatory curves
alone due to no cusp height.
 Sear advocated the use of:
1) 2nd molar ramp to provide protrusive, lateral
balance.
2)Or denture base ramp.
 Put wax on the retromolar area before flasking so
converting to acrylic.

5- ZERO-DEGREE TEETH WITH REVERSE
LATERAL CURVE "WILSON" AND A RAMP:
 The flat teeth are set at reverse curve laterally
Wilson " anti-monson curve" but with 2nd molar
ramp for balancing contact anteroposteriorly.
 This scheme direct occlusal forces inside crest
lingually, ↑ stability of mandibular denture.
 This reverse occlusal scheme has its curvature
low level of survey line.

6- FLAT TEETH WITH MAX PLEASURE
SCHEME:
 Mandibular premolars are arranged on reverse
curve “Wilson”.
 1st Molars are arranged on flat horizontal plane.
 2nd Molars are arranged on Monson curve [For
lateral stability]
 Distal to 2nd molar is elevated "Vertical ramp“.
 In the area of premolar: the bone is narrow so the
force should be directed lingually to stablize the
denture.
 In the area of molars: buccal shelf of bone thick
so we set the molars in a manner to direct the
force buccally to provide more stability.

7- LINEAR CONCEPT:
 In it, masticatory surface of lower posterior teeth has
straight long narrow occlusal form resembling a line
articulate with opposing monoplane teeth.
 Cutter plane teeth: maxillary & mandibular posterior
teeth are flat with single mesiodistal sharp ridge run
along occlusal surface of lower posterior teeth.
 * Advantages of both linear concept & cutter plane
teeth:
2)Low Forces needed for food penetration→ low forces
on the ridge.
3) Lever balance.
4) Eliminate occlusal deflective contact → ↑ Stability.

 Different Occlusal forms used to develop linear
concept:
1) Upper flat porcelain teeth opposing lower porcelain
linear teeth.
2) Upper flat plastic teeth opposing lower plastic linear
teeth.
3) Upper flat acrylic teeth opposing lower porcelain
linear teeth.
4) Upper anatomic porcelain teeth opposing lower
plastic flat teeth.
5) Upper flat teeth opposing lower cutter plate (ridge
running anteroposterior).
 If anterior is porcelain and posterior is acrylic →
cause problems.
 But the correct one -> anterior is acrylic & posterior is
porcelain.

8- LINGUALIZED OCCLUSION:
 In this concept, there is reduction of efficiency on
lower buccal cusps so that, there is no lateral
thrust against buccal cusp.
 this develops a lingualized occlusion utilizing
only 5 lingual cusps of upper artificial teeth
[ palatal of 4th, 5th, 2 of 6th and mesiopalatal of
7th] on each side to act as cutters operating in
central fossa of lower teeth.
 Maxillary lingual cusps act as centric holding
cusps in mortar & Pestle design.

(a) Normal occlusion and (b) lingualized
occlusion
Lingualized balanced occlusion:
Protrusion
Lingualized balanced occlusion: Lateral
excursion

 Advantages:
1) It creates a more lever by moving the centric contact.
 Half tooth to the lingual, this result in more stability of the
denture.
2) It centralize the occlusal forces over the ridge crest, except
in the 1st molar area where it is slightly lingual.
3) There is only one contact point, this creates mortal &
pestle type of occlusion that provides a small area of contact
for more efficiency& control of lateral fossa.
4) It minimize the frictional contact between upper & lower
occlusal surfaces as there is only one area of contact.
5) Buccalization or reduction of buccal cusps allows an escape
away for the bolus of food & reducing forces on the
supporting tissue.
6) It simplifies the working & balancing contacts because
there is only cusp to contact.
7) It can be used with all ridge contours.

B. NON-BALANCED OCCLUSION:
 Definition: Non-balanced occlusion means maximum
planned contact or intercuspation at centric occlusion
without emphasizing the contact relation in eccentric
position.
 The Criteria to accept the concepts of non-balanced
occlusion:
1. The teeth contacts in centric relation during
masticatory & non-masticatory movements.
2. The artificial teeth should not contact in eccentric
relations as this leads to horizontal torqueing forces to
the supporting tissue, which lead to instability of the
denture & destruction of supporting tissues.
3. The patient is encouraged to mastication in centric
relation only as more tolerated & less destructive to the
tissues.

THE CONCEPTS OF NON-BALANCED
OCCLUSION IN ECCENTRIC POSITION.
1 The monoplane (neutrocentric) occlusion.
2 The organic concept of non-balancing occlusion
(Canine protected occlusal).
3 The lingualized unbalanced occlusion.
4 Occlusal pivots.
5 Non-anatomic teeth with flat anteroposterior
plane and a reverse lateral curve.

1- THE MONOPLANE (NEUTROCENTRIC)
OCCLUSION:
 The monoplane concept (First advocated by Devan) utilized zero-
degree (flat) teeth & made the occlusal plane perfectly flat &
parallel to and evenly dividing the upper & lower residual ridge.
 This completely eliminates inclined planes not only in the tooth
form but also in the occlusal planes so that not lateral
component can be generated with vertical chewing force.
 The occlusal plane was made to fall at the junction of upper&
middle third of retromolar pad.
 Devan's concept of neutrocentric occlusion embodies the
centralization of occlusal forces which act on the basal seat,when
the mandible is in centric relation to the maxilla.
 The term neutrocentric is not related to bone relationship but is
a concept of occlusion that eliminates any anteroposterior or
buccolingual inclines of the teeth using cuspless teeth & directs
the occiusal forces vertically to the posterior teeth.

 Advantages of the monoplane occlusion:
 1) More adaptable to unusual jaw relations as
Class Il & ll malocclusion.
 2) More easily used where variation of width of the
upper & lower jaws indicate a cross bite setup.
 3) Zero-degree teeth give the patient a sense of
freedom because they don't lock the mandible in
one position only.
 4) They eliminate horizontal forces that may be
more damaging than vertical forces.
 5) Zero-degree teeth permit the use of simplified &
less time consuming technique.
 6) They also offer greater comfort & efficiency
for longer period.
 7) They accommodate better to the inevitable
negative changes in ridge height.

FEATURES OF MONOPLANE CONCEPT:
 The occlusal plane should be parallel anteroposteriorly
with the plane of denture foundation not dictated by
the horizontal condylar guidance.
 The teeth are set flat in mesiolateral direction with
no medial or lateral inclination.
 The patient is instructed to avoid incising with the
anterior teeth.
 If incising occur → space posteriorly → low stability.

 Articulator Features:
 Since the teeth are not arranged in balanced
occlusion, the horizontal & lateral condylar
guidance's of articulator may be set at zero.
 The condylar element of the articulator are secured to
function in opening & closing movement only.
 * Features of the Teeth:
 The buccolingual width of the teeth is reduced
to direct the force towards the center of the support
end to reduce the frictional forces.
 The number of teeth are reduced to direct the
forces in the molar & premolar area and to avoid
placing a tooth on the posterior upward incline of the
ridge in the second molar area.
 No over bite.

 Types of teeth used for monoplane concept:
 1)Upper & lower all porcelain teeth.
 2) Upper & lower all plastic teeth.
 3) Combination of upper posterior porcelain teeth
& lower plastic teeth.
 4) Vitallium occlusal insert teeth.
 5) Orthoplane teeth.

2- THE ORGANIC CONCEPT OF NON-BALANCING
OCCLUSION: (CANINE PROTECTED OCCLUSION).
 Also called "Mutually protected occlusion".
 This concept used cusp form posterior teeth
(anatomic teeth) that are not arranged in
protrusive& bilateral balance.
 It is a part of gnathological concept; it is characterized
by disocclusion by cusped guidances in eccentric
position.
 Organic concept is offered by movement of mandible,
which is guided by TMJ, muscles but not teeth.
 As so, to make this concept we must use with the
fully adjustable articulator we need pantogram to
have true hinge axis and kinematic facebow.

 Phases of organic concept:
- The organized occlusion has 3 phases of mutually
interdependent protection:
 1) The posterior teeth should protect the anterior
teeth in the centric occlusal position.
 2) The incisors should have vertical overlap (over
bite) sufficient to provide separation of posterior teeth
when the incisors are in edge to edge contact in the
protrusive movement.
 3) In lateral mandibular position, the cuspids
(canines) should prevent contact of all other teeth
"cuspids of lateral working side" (Canine rise
protection).

 Canine Rise (Cusped protection):
 In this concept, the canine is the only tooth that
provides contact or guidance on the working side.
Canine rise occur naturally.
 The canine is physiologically suitable to support this
function with all posterior teeth clearing on both the
working & balancing sides, the articulator errors are
eliminated.

IMPORTANCE OF HINGE AXIS TO THIS
CONCEPT:
 The aim of this concept is to relate the cusps that they
will be in harmony with the muscles & joint in function.
 The muscles & joints should determine the mandibular
position of occlusion without tooth guidance.
 The mandibular position of occlusion is the terminal
hinge axis.
 In function, the teeth should always be passive to the
path of the mandibular movement, never dictate them.
 When the mandible is moved in a eccentric position,
protrusive or lateral separation of the posterior teeth
occurs wither due to incisal guidance or canine rise.
 The posterior teeth are altered by grinding & inclined to
provide alack of contact on the working & balancing sides
in eccentric position.
 The cusps are altered to a cusp-fossa centric relation in
whom the cusp can enter the fossa & escape without
lateral or anteroposterior interference.

 In this concept, the position of maximum
intercuspation coincide with the retruded position of
the mandible & all posterior teeth are in contact with
the force directed with the long axis of the teeth, the
anterior teeth are slightly out of contact
(approximately 25 micro)
 This concept needs an articulator, which receive &
reproduce pantogram in 3 planes.
 The mutually protected occlusion or canine rise or
organic concept is the most widely accepted because
of its, greater area of fabrication & patient tolerance,
it cannot be used for class II & III malocclusion.
 Notes: Muscles & joint are the only factors that
determine the organic concept.
Teeth used for organic concept:
1) Modified anatomic teeth.
2) 33° cusp form teeth with full gold occlusal surface.

3- THE LINGUALIZED IN UNBALANCED
OCCLUSION:
 Lingualized unbalanced occlusion gives unbalanced
occlusal provided both a limited range of excursive
balance & directing the forces to the lingual side
during working side contact.
 This concept minimize the horizontal stress &
enhances denture stability by controlling the
leverage induced by eccentric tooth contact.
 This concept is achieved by using a sharp upper
lingual cusp in the posterior teeth opposing a
widened central fossa on lower posterior teeth.
 In centric occlusion reducing the lower buccal cusps
& elimination of deflective occlusal contacts.

4- OCCLUSAL PIVOTS:
 There are non-anatomic “cuspless” teeth, which are arranged
high in the 1st & 2nd molar regions.
 It is also explained as an elevation placed on the occlusal
surface usually in the molar region.
 The values of occlusal pivots as mentioned by Sear are:
1) The mandible is placed equilibrium by maintaining the load in
the molar regions.
2) It protects the TMJ against injury
3) The stressed are also reduced in the anterior regions of the
ridge in an anticipation of tissue maintenance.
 In cases of old denture:
 The occlusal pivot is used by placing mix of acrylic resin on the
occlusal surface of the 2nd premolar & the 1st molar region.
 Covering it by tin foil & extended buccally & lingually on the
side of these areas, which allow acrylic resin to set.
 Then remove the tin
 Finish and polish the resin.

5- NON-ANATOMIC TEETH WITH FLAT
ANTEROPOSTERIOR PLANE AND A REVERSE
LATERAL CURVE:
 The flat teeth arranged on a flat anteroposterior
occlusal plane with a reverse lateral curve
“Wilson” without a posterior ramp resulting
in a non-balancing occlusion in eccentric position.
 But if posterior ramp present, balanced occlusion
will occur and this not wanted here.

occlusion of complete denture teeth.pptx

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