Occlusion in Complete Denture

Presented by:
Dr. Jehan Dordi
2nd Yr., MDS
1
OCCLUSION IN COMPLETE DENTURE

Contents
2
o INTRODUCTION
o DEFINITIONS
o DIFFERENCE BETWEEN NATURAL AND ARTIFICIAL
OCCLUSION
o FORCES OF MASTICATION
o REQUIREMENTS OF COMPLETE DENTURE OCCLUSION
o TYPES OF ARTIFICIAL TEETH
o THEORIES OF OCCLUSION

3
o CONCEPTS OF OCCLUSION
o REVIEW OF LITERATURE
o CONCLUSION
o REFERENCES

5
o Occlusion is a factor that is common to all branches of dentistry.
o It is a term generally accepted to describe the contact relationship of the
upper and lower teeth.
o Every time opposing teeth contact there is a resultant force.
o Although this force may vary in magnitude and direction, it must always be
resisted by supporting tissues.
o Control of this resultant force is a basic and perplexing problem.

NOMENCLATURE AND TERMINOLOGY
6
Occlusion:
1. The act or process of closure or of being closed or shut off;
2. The static relationship between the incising or masticating surfaces of the
maxillary or mandibular teeth or tooth analogues. – GPT 9

7
• Articulation:
1. the place of union or junction between two or more bones of the
skeleton;
2. in speech, the enunciation of words and sentences;
3. in dentistry, the static and dynamic contact relationship between the
occlusal surfaces of the teeth during function – GPT 9

DIFFERENCE BETWEEN
NATURALAND
ARTIFICIAL OCCLUSION
8

Natural Teeth
Denture Teeth
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1. Retained by periodontal tissues
that are uniquely innervated and
structured.
2. Teeth receive individual
pressures of occlusion and can
move independently.
3. Malocclusion may be uneventful
for years.
1. All the teeth are on bases seated
on slippery tissues.
2. Teeth move as a unit on their
base.
3. Malocclusion evokes an
immediate response and involves
all of the teeth and the base.

Natural Teeth Denture Teeth
10
4. Non vertical forces affect
only the teeth involved and
are well tolerated
5. Incising does not affect the
posterior teeth.
6. Second molar is the favored
area for masticating hard
foods, owing to more
favorable leverage and
power.
4. Non vertical forces affect all
of the teeth on the bases and
are traumatic to the
supporting structures.
5. Incising affects all of the
teeth on the base.
6. Heavy pressures in the
second molar region will tilt
the base and shift it, if it is
on an inclined foundation.

Natural Teeth Denture Teeth
11
7. Bilateral balance is rarely
found; if present, considered
balancing side interference.
8. Proprioception avoids
prematurities and
interferences and establishes
a stable habitual occlusion
away from centric relation.
7. Bilateral balance is
favourable for base stability.
8. No proprioception. If cusps
interfere or prematurities
exist, the bases will shift on
the foundation tissues.

13
o Force necessary to masticate food with natural teeth vary - 5 to 175
pounds.
o Wide range of force is due to
• Choice of foods
• Condition of the supporting structures of the teeth
• Integrity of the crown
• Muscular development
o The average force in denture wearers in the molar and bicuspid area during
mastication as 22–24 pounds and dropped to 9 pounds in incisor area
o Average closing force during mastication of denture wearers - 11.7 pounds

14
o The comparison shows that denture wearers can exert only from
10% to 15% of the force of a patient with good natural teeth.
o So average complete denture wearer has barely adequate force for
the work required during mastication.

REQUIREMENTS OF COMPLETE
DENTURE OCCLUSION
15

16
1. Stability of occlusion at centric relation position, in an area
forward and lateral to it.
2. Balanced occlusal contacts bilaterally for all eccentric
mandibular movements.
3. Unlocking the cusps mesiodistally to allow for gradual setting of
the bases due to tissue deformation and bone resorption.
4. Control of horizontal force by buccolingual cusp height
reduction according to residual ridge form and interarch
distance.
5. Functional lever balance by favorable tooth to ridge crest
position.
6. Cutting, penetrating and shearing efficiency of occlusal surfaces.

These requirements can be most easily
applied if the occlusion is divided into
3 distinct units
Incising unit
Working occlusal unit
Balancing unit
17

Requirements for Incising Units
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o Be sharp  cut efficiently
o No contact during mastication
o Contact only during protrusive incising function
o Have as flat an incisal guidance as possible considering esthetics and
phonetics
o Have horizontal overlap to allow for base settling without interference

Requirements for Working Occlusal Units
19
o Efficient in cutting and grinding
o Decreased buccal-lingual width to minimize the work force directed to the
denture foundation
o Function as a group with simultaneous harmonious contacts
o Be over the ridge crest in the masticating area for lever balance
o Have a surface to receive and transmit the force of occlusion vertically
o Center the work load near the anteroposterior center of the denture
o Present a plane of occlusion as parallel as possible to the mean foundation
plane

Requirements for Balancing Occlusal Units
20
o Contact on the second molars when the incising units contact in
function
o Contact at the end of the chewing cycle when the working units contact
o Have smooth gliding contacts for lateral and protrusive excursions

Axioms for Artificial Occlusion
21
These axioms were published by Sears and have guided the
planning of complete denture occlusion for many years:

• Smaller the area of occlusal surface
acting on food
• Vertical force to an inclined occlusal
surface
• Vertical force to a denture base
supported by yielding tissue
• Vertical force outside (lateral) to the
ridge crest
• Vertical forces to inclined supporting
tissues
• Smaller will be the crushing force
• Non vertical force on the denture
base
• The base teeters if the force is not
centered on the base
• Tipping forces on the base
• Non vertical forces on the denture
base

Occlusal Schemes Used In Complete Denture
23
• The tooth in a denture  mechanical replacement of lost natural tooth
• The design of the posterior teeth can be divided into 2 main group:
Anatomic teeth
Semi anatomic/
Non anatomic
teeth

• ANATOMIC  330 bucco-lingual inclines
of anatomic teeth for patients with strong,
well formed ridges
• SEMIANATOMIC 200 bucco-lingual
inclines of semi-anatomic teeth for patient
with reduced ridge contour
• NON ANATOMIC 00 non-anatomic teeth
for patient with flat, knife edge ridges
24

26
• Many types of posterior teeth have been designed to meet the needs of various
philosophies of complete denture occlusion.

Anatomic Teeth of 33 Degrees or More
27
o Historians give Dr. Alfred Gysi the credit for creating the first anatomic porcelain tooth
designed to function harmoniously with incisal and condylar guidances.
o They had transverse ridges and were intended for tight interdigitation in an Angle class I
occlusion. These teeth were called "Trubyte ”
o In 1932, Pilkington and Turner patented a new anatomic posterior tooth form having a
slightly shallower cusp of 30° but closely resembling natural occlusal forms.

28
o These carvings were supposedly arrived at mathematically.
o These provided a small degree of freedom in protrusive excursions but were
still tightly interlocked in lateral excursion.

Modified Anatomic Teeth between 30 Degrees and 0
Degrees
29
• It has been a matter of controversy for years as to why artificial posterior
teeth should resemble natural teeth.

30
o Gysi recognized that his anatomic teeth would not satisfy all ridge
relationships
o In 1927, he designed a modified “cross-bite” posterior
o Maxillary buccal cusp was almost eliminated  one prominent lingual cusp
that occluded into a lower anatomic tooth.
o Occlusal surfaces reduced
o Gysi described a “mortar-and- pestle” action of this occlusal scheme

31
o Victor Sears in 1922 and in 1927 designed the “channel” tooth
o Maxillary occlusal surfaces consisted of a deep channel that ran mesiodistally
the entire length of the four posterior teeth.
o Lower posteriors  approximately half the buccolingual width and single
central ridge
o They articulated with the central channel of the maxillary teeth and permitted
unlimited protrusive glide with inclines that limited lateral glide.

32
o In 1930, the Avery brothers introduced the “scissor-bite” technique (the
opposite of Sears).
o Posterior occlusal surfaces were locked anteroposteriorly by grinding steps on
the surface of the teeth, with the angle determined by the inclination of the
condylar path.
o Free in lateral excursion
o Occlusion of these teeth scissors together  shear food in lateral excursions

33
o McGrane, in 1936, designed the “curved
cusp” posterior tooth
o Lock anteroposteriorly and be free
laterally in an arc corresponding to an
arbitrary radius from each vertical
rotational axis of the right and left
condyle.
o So shears food in harmony with the lateral
condyle guidance of the Bennett angle

34
o In 1935, French designed a severely modified tooth.
o Maxillary tooth had a central groove running mesiodistally (similar to Sears’s)
but with very shallow buccolingual inclines to reduce lateral thrust

35
o Mandibular teeth had a narrow mesiodistal food table moved to the
lingual of the occlusal surface and a sloping buccal incline that was
subocclusal
o This design placed the axial occlusal forces lingually, which favored the
stability of the lower denture

36
o Max Pleasure proposed in 1937, to
modify the lower posterior teeth
occlusal surfaces to a reverse curve by
tilting the tooth buccally.
o No balancing contacts in either lateral
or protrusive excursions.
o Was later modified to provide
balancing contacts.

37
o The reverse curve was set in the premolars, a flat occlusal surface on the
first molar and a Monson curve (lingual tilt) at the second molar for
balance.
o The reverse curve (buccal tilt of occlusal surfaces) is created to direct
forces of occlusion lingually to favor the stability of the lower denture,
while still retaining a balancing contact in the second molar

38
o John Vincent, in 1942, introduced a change in materials by using metal
inserts in resin posteriors.
o Originally gold solder wire and later stainless steel inserts were circles
of metal that protruded from the middle third of the maxillary posterior
occlusal surfaces with shallow buccal and lingual cusps protruding
beyond the metal inserts.

39
o These teeth were set opposing French’s mandibular posteriors.
o Primary advantage was the self-adjusting quality of the resin teeth as
they wear against the porcelain teeth.

40
• In 1941, S.H. Payne described the modification of anatomic teeth set to a
“lingualized occlusion” concept

41
o Sosin replaced the maxillary second bicuspid and first and second
molars with cleat-shaped Vitallium forms, called “cross-blades,” of
slightly smaller size.
o The dentures were brought to the try- in stage, the lower molars were
removed, and the case processed.

42
o At the time of insertion, wax was placed in this area, the dentures
inserted, and the patient “chewed” the occlusal form into the wax. This
was then converted to gold and cured to the existing lower denture.

44
o A recent modified occlusal scheme was described by Levin; as
modification to the one proposed by Sosin.
o Levin modified this scheme by reducing the size of the cross-blade to
the maxillary lingual cusp (for esthetic reasons).
o Both authors claim a great increase in masticatory efficiency.

46
• Myerson’s FLX “freedom in lateral excursion” posteriors

Nonanatomic or 0-Degree Cuspless Teeth
47
o The presence of cusps on artificial teeth was felt by many dentists to
present problems that were too difficult to control.
o Because of these difficulties, the cuspless tooth design emerged.

48
o Hall - the first to design and utilize a cuspless tooth called an
“inverted cusp tooth” in 1929
o Tooth was flat with concentric cone-shaped depressions on the
occlusal surface that were like inverted cusps.

49
o It created a flat occlusal surface with sharp concentric ridges around the
cuplike depressions
o This was claimed to provide an efficient shredding action on food

50
o Myerson also designed a cuspless posterior tooth in 1929, which
he called “True-Kusp”
o It had a series of transverse buccal-lingual ridges with sluiceways
between them

51
o In 1934, Nelson described teeth he
called “chopping block” posteriors,
which were flat occlusal surfaces
with numerous ridges.
o The ridges on the mandibular teeth
ran transversely and on the maxillary
they ran mesiodistally.

52
o Because they were perpendicular to one another in contact, an efficient
shredding and cutting action was claimed

53
o In 1939, Swenson designed a posterior tooth he called “non-
lock”
o Essentially flat teeth with sluiceways for shredding and allowing
food to clear the occlusal table.

54
o They did provide balancing contacts, as a modest buccal and lingual
incline was provided

55
o Hardy, in 1946, designed a metal insert upper and lower posterior which
he called “VO” (Vitallium Occlusal).
o Produced in resin blocks of three posterior teeth simulating a buccal
facade of two bicuspids and one molar

56
o Narrow zigzag of Vitallium ribbon embedded on the occlusal surface,
establishing a narrow, flat, convoluted metal surface that was raised
slightly above the encasing resin
o Articulating surfaces of these teeth were metal-to-metal ribbons that
proved to be effective cutters

58
o In 1951, the Myerson Tooth Corporation introduced the first cross-linked
acrylic tooth in a flat occlusal scheme called the “shear-cusp” tooth

59
o Most unusual nonanatomic posterior teeth - Coe Masticators
designed by Cook in 1952.
o The second premolar and the first molar were flat stainless steel
castings with holes on the occlusal surfaces that exited diag-
onally to a port on the buccal surface

60
o With an intent to increase the masticatory efficiency of flat
teeth, Bader, in 1957, introduced the “cutter-bar” scheme by
opposing upper porcelain cuspless teeth with a metal cutting
bar replacing the second bicuspid, first molar and second
molar.

61
o Frush in 1967, described a “linear occlusal concept”
o Maxillary and mandibular posteriors were flat, with a single mesiodistal
ridge usually on the lower
o The idea was to minimize the force of penetrating food by sharp linear
contact

PROBLEMS WITH ANATOMIC TOOTH FORMS
62
o The use of an adjustable articulator is mandatory.
o Eccentric records must be made for articulator adjustments. Setting
the adjustments will vary from dentist to dentist with the same rec-
ords.
o Mesiodistal interlocking will not permit settling of the base without
horizontal forces developing.
o Harmonious balanced occlusion is lost when settling occurs.

63
o The bases need prompt and frequent refitting to keep the
occlusion stable and balanced.
o The presence of cusps generates more horizontal force during
function.

PROBLEMS WITH NONANATOMIC TOOTH FORMS
64
o Occlude in only two dimensions (length and width), but the mandible
has a three-dimensional movement
o Vertical component present in mastication and nonfunctional
movements is not provided for, so that this form loses shearing
efficiency
o Bilateral and protrusive balance is not possible with a purely flat
occlusion.

65
o When set on inclines for balance, it require as much concern as
anatomic teeth for jaw movements.
o Do not function efficiently unless the occlusion surface provides cutting
ridges and generous spillways (sluiceways).

66
o Cannot be corrected by much occlusal grinding without impairing
their efficiency.
o Appear dull and unnatural to some patients and may create a
psychological problem concerning function.

Cusp form Advantage
Anatomic
occlusion
 Penetrate food more easily
 Resist rotation of denture bases through
cusp interdigitation
 Provide better esthetics
 Act as a guide for proper jaw closure
Non anatomic
occlusion
 Does not lock the mandible in one position
 Less time consuming procedure
 Minimises horizontal stress
 Easier to arrange in cross bite
68

Cusp form Disadvantage
Anatomic
occlusion
 Precise jaw closure and base stability
required for interdigitation
 Increased horizontal forces
Non anatomic
occlusion
 Poor esthetics
 Decreased masticatory efficiency
 More difficult to get balanced occlusion
69

Theories Of Occlusion
71
o Spherical theory
o Equilateral triangle theory
o Conical theory

Spherical theory
72
o Monson in 1918
o Positioning of teeth with antero-posterior
and medio-lateral inclines in harmony
with a spherical surface. Some times
referred to as having Monson curve.

73
o Lower teeth moves over the surface of upper teeth as over the surface of
sphere with a diameter of 8 inches (20cm).
o Centre of sphere is in glabella.
o Surfaces of the sphere passes through glenoid fossa along the articular
eminences.

Equilateral triangle theory
74
o This theory was proposed by Bonwill.
o The distance between the condyles is equal
to the distance between the condyle and the
midpoint of mandibular incisors.
o It forms a 4 inches equilateral triangle.

Conical theory
75
o This theory was proposed by Hall
o Lower teeth move over the surfaces
of the upper teeth as over the surfaces
of cone with a generating angle of 45
degree with the central axis of the
cone tipped 45 degree to the occlusal
plane.

76
CONCEPTS OF
COMPLETE DENTURE
OCCLUSION

Static concept:
77
o Static relations - centric occlusion, protrusive occlusion, right and left
lateral occlusion
o All of these relations must be balanced  simultaneous contacts of all
the teeth on both sides at their very first contact
o Cuspal inclines developed so  teeth can glide from a more centric to
eccentric positions without interference and rotating or tipping forces

Dynamic concept:
78
o Primarily concerned with opening and closing movements of
mastication
o Jaw movements and tooth contacts made, as the teeth of one jaw glide
over the teeth of the other.

79
• Occlusal rehabilitation in complete denture fall into four
occlusal concepts
• Unbalanced articulation
• Balanced articulation
• Linear or monoplane articulation
• Lingualized articulation

CONCEPTS PROPOSED TO ATTAIN BALANCED
OCCLUSION
80

Gysi concept
81
o In 1914, 33° cuspal form was introduced by Gysi.
o 33° of cuspal inclines to harmonize them with the condylar inclination
of 33°
o In lateral mandibular movements, cusps contact bilaterally to enhance
the stability of the dentures
Beck HO. Occlusion as related to complete removable prosthodontics. J Prosthet Dent 1972;27:246-62

82
A) In centric occlusion, the masticatory forces directed toward the
ridges
B) In right lateral position, the occlusal contact forces are directed away
from the ridges.
• In extreme working lateral position, contacts on both cusps incline,
contact force are also directed outside the ridges

French concept
83
o Occlusal surface of the mandibular posterior teeth had been reduced to
increase the stability of the dentures
o The maxillary posterior teeth have slight lingual occlusal inclines of 5°
for first premolar, 10° for second premolar, and 15° for first and second
molars,
o So that a balanced occlusion could be developed laterally as well as
anteroposteriorly by the arrangement of teeth on a curved occlusal
plane.

84
o In centric occlusion, half of width of mandibular posterior teeth
helps to direct the masticatory forces in a buccal direction to the
mandibular residual ridge.
o In a right lateral position, the occlusal contact forces are directed
toward the ridges on the working side and away from the ridges on
the balancing side

Sears concept
85
o Sears in 1922 with his chewing members and in 1927 with channel teeth
(both were nonanatomic teeth) developed  balanced occlusion by a
curved occlusal plane anteroposteriorly and laterally or with the use of a
second molar ramp

86
o In centric occlusion, nonanatomic teeth will exert contact forces
toward the ridges.
o In the right lateral position, the occlusal contact forces directed
toward the ridge on the working side and toward the buccal side of
the ridge on the balancing side

Pleasure concept
87
o In 1937, Dr. Max Pleasure presented an occlusal scheme called the
“pleasure curve”
o In which a reverse curve is used in the bicuspid area for lever balance,
o a flat scheme of occlusion is set in the first molar area, and
o a spherical scheme set in the second molar area by raising the buccal
incline to provide for a balancing contact in lateral position

88
o Pleasure rationalized that the occlusion should be of special design due
to the instability of the lower denture.
o Resultant forces should be directed vertically and/or lingually.

Frush concept
90
o In 1967, Frush gave the “Linear occlusal concept” which employed an
arbitrary articulator balance, followed by intraoral corrections to obtain
balance.
o A single mesiodistal ridge on the lower posterior teeth contacted a flat
occlusal surface of the upper posterior teeth set at an angle to the
horizontal.
o The intention was to eliminate deflective occlusal contacts and
increased stability.

91
A) In centric occlusion, contact forces directed toward the ridges
according to the linear occlusal concept.
B) In a right lateral position, the contact forces toward the ridge on the
working side and slightly toward the buccal side of the lower ridge on
the balancing side at a given inclination of 6°

92
Hanau's Quint
Hanau R. Articulation defined, analyzed, and formulated. J Am Dent Assoc 1926;13:1694-709

In 1925, Rudolph L. Hanau presented a discussion paper entitled,
"articulation: defined, analyzed, and formulated"
93
He believed articulation of artificial teeth was related to nine
factors:
o Horizontal condylar inclination
o Compensating curve
o Protrusive incisal guidance
o Plane of orientation

94
o Buccolingual inclination of tooth axes
o Sagittal condylar pathway
o Sagittal incisal guidance
o Tooth alignment
o Relative cusp height

95
o He mathematically charted the nine factors and listed the laws of
balanced articulation in a series of 44 statements.
o Hanau later combined the original nine factors and reduced them to five.
Levin B. A reevaluation of Hanau’s Laws of Articulation and the Hanau Quint. J Prosthet Dent 1978;39:254-8

96
o Thielemann subsequently simplified Hanau's factors in a formula for
balanced articulation.
[K × I]/[OP × C × OK]
Where, K = Condyle guidance
I = Incisal guidance
C = Cusp height inclinations
OP = Inclination of the occlusal plane
OK = Curvature of the occlusal surfaces

Trapozzano concept
97
o Trapozzano reviewed Hanau’s five factors and decided that only three
factors were actually concerned in obtaining balanced occlusion.
o He eliminated the plane of orientation since its location is highly
variable within the available inner ridge space.

98
o He also suggested that the occlusal plane can be located at various
heights to favor a weaker ridge.
o Trapozzano stated, no need for a compensating curve, as it is obsolete
since the cuspal angulation will produce a balanced occlusion.

Boucher concept
100
There are three fixed factors:
o The orientation of the occlusal plane, the incisal guidance and the
condylar guidance
o The angulation of the cusp is more important than the height of the cusp
o The compensating curve enables one to increase the effective height of
the cusps without changing the form of the teeth

The Lott concept
101
He stated the laws as follows:
o The greater the angle of the condyle path  the greater is the posterior
separation
o The greater the angle of the overbite  the greater is the separation in
the anterior region and the posterior region regardless of the angle of the
condylar path

102
o The greater the separation of the posterior teeth  the greater must be
the compensation curve
o The greater the separation of the teeth  the greater must be the
posterior teeth height

Bernard Levin’s concept
104
• Bernard Levin’s concept of the laws of articulation is quite similar to
Lott’s, but he eliminated the plane of orientation.
He has named the four factors as Quad. The essentials are as follows:
o CG is fixed and recorded from the patient.

105
o The IG 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 IG is considered to be helpful when the residual
ridges are flat.

106
o Compensating curve is the most important factor for obtaining balance.
o Monoplane or low cusp teeth must employ the use of a compensating
curve.
o Cusp teeth have the inclines necessary for obtaining balanced occlusion
but nearly always are used with a compensating curve.

BALANCED OCCLUSION
108
o It is defined as the bilateral, simultaneous occlusal contact of the
anterior and posterior teeth in excursive movements – GPT 9
o The simultaneous stable contact of opposing upper and lower teeth in
centric relation position and a continuous smooth bilateral gliding
from this position to any eccentric position within normal range of
mandibular function

Objective of Balanced Complete Denture
109
o Occlusal balance with stable contacts at the retruded border
position and in an area anterior to it.
o Right and left eccentric occlusal balance by simultaneous
contacts at the limit of functional and parafunctional activity.
o Intermediate occlusal balance for all positions between centric
occlusion and all other functional or parafunctional excursions
to the right and left and protrusive.

Importance Of Balanced Occlusion
110
o Improved stability of denture
o No single tooth will produce any interference or disocclusion of the
other teeth.
o Preservation of ridges by better distribution of forces

Characteristic Requirements Of Balanced Occlusion
111
o All the teeth of the working side should glide evenly against the
opposing teeth.
o There should be contacts in the balancing side, but they should not
interfere with the smooth gliding movements of the working side.
o Simultaneous contact during protrusion.

Following Points Should Be Considered:
112
o Wider and larger the ridge and closer the teeth are to the ridge
 the greater the lever balance
o Smaller and narrower the ridge and the farther the teeth are
placed from the ridge  poorer the lever balance

113
o Wider the ridge and the narrower the teeth  the greater the balance
o Narrower the ridge and wider the teeth  poorer the balance
o The more lingual the teeth are placed in relation to the ridge  the better
the balance

114
o The more buccal the teeth are placed to the ridge crest  the poorer the
balance
o The force of occlusion must be centered antero-posteriorly, in the
denture the greater the stability of the base.

“ENTER BOLUS, EXIT
BALANCE”
115
o The echoes through the years of this statement by Sheppaard
has cast suspicion as to whether smooth, gliding, non-
interfering, bilateral tooth contacts are possible.
o It implies that occlusal balance is impossible during
mastication.
o When a bolus of food separates the teeth then why is
Balancing Needed???????
Sheppard IM, Sheppard SM. Denture occlusion. J Prosthet Dent.1968;20:307-18

116
o Allen Brewer and Donald Hudson have shown that complete
denture teeth do contact at times during mastication.
o The average patient masticates food for only 10 or 15 minutes,
two or three times daily.
Allen A .Brewer and Donald C. Hudson - J Prosthet.1961:11:1:62-72

117
o During the remainder of the day, the teeth are in occlusal contact many
times in centric and eccentric positions with no food between them
o Even during the process of chewing food, the teeth will cut through the
bolus frequently, and contact will be made on the balancing side.

118
o Balance is also deemed necessary during many excursive movements
such as swallowing saliva, closing to reseat dentures, and bruxing
performed by patients in between meals.
o Hence, if the balance is not present, the bases could shift, tip or torque
on their foundations during the eccentric movements and cause
inflammation leading to accelerated bone resorption.

Types of Balanced Occlusion
119
Balance may be:
o Unilateral
o Bilateral
o Protrusive

120
• Unilateral lever balance: this is present when there is
equilibrium of base on its supporting structures when a bolus of
food is interposed between teeth on one side and space exists
between teeth on the opposite side.

121
This can be achieved by:
o Placing the teeth so that the resultant duration of force on the functioning
side is over the ridge or slightly lingual to it.
o Having the denture base cover as wide an area on the ridge as possible.
o Placing the teeth as close to the ridge as possible.
o Using as narrow buccolingual width occlusal food table as possible.

122
Unilateral occlusal balance:
o This is present when the occlusal surfaces of teeth on one side articulate
simultaneously, as a group, with a smooth uninterrupted slide.

123
• Bilateral Occlusal Balance :
o This is present when there is equilibrium on both sides of the denture
due to simultaneous contact of the teeth in centric and eccentric
occlusion.
o It requires a minimum of three contacts for establishing a plane of
equilibrium.

124
o The more the contacts, the more assured is the equilibrium.
o This type of balance is dependent on the interaction of the incisal
guidance, the plane of occlusion, the angulation of the teeth (tilt and
inclination), the cusp angulation (height), the compensating curve, and
the inclination of the condylar path.

125
• Protrusive Occlusal Balance:
o Present when the mandible moves forward and the occlusal contacts are
smooth and simultaneous in the posterior both on right and left sides and
on the anterior teeth.

126
o It is slightly different from bilateral balance in that it requires a minimum
of three contacts, one on each side posteriorly and one anteriorly.
o This is dependent on the interaction of the same factors as bilateral
occlusal balance.

127
• This total concept of balanced complete denture occlusion must be
considered in terms of the following:
1. The tooth size and position in relation to the ridge size and shape.
2. The extent of denture base coverage.
3. Occlusal balance with stable contacts at the retruded border position and
in an area (long centric) anterior to it.

128
4. Right and left eccentric occlusal balance by simultaneous contacts at the
limit of functional and parafunctional activity.
5. Intermediate occlusal balance for all positions between centric occlusion
and all other functional or parafunctional excursions to the right, left and
protrusive. (This balance is probably the most important, as it allows for
smooth uninterrupted tooth contacts in the dynamics of daily
mandibular movements.)

FACTORS THAT AFFECT OCCLUSAL BALANCE
129
o Incisal Guidance
o Condylar Guidance
o Plane of Occlusion
o Cusp Angulation
o Compensating Curve

Condylar Guidance
130
1. Mandibular guidance generated by the condyle and articular disc
traversing the contour of the articular eminence
2. The mechanical form located in the posterior region of an articulator
that controls movement of its mobile member – GPT 9

131
o It is the mandibular guidance generated by the condyles traversing the
contours of glenoid fossa.
o It is one of the end controlling factor. It is independent of tooth contact.
o It is recorded from the patient by protrusive record

132
o The pathways followed by condyles are inherent for the patient and are
not controlled by the dentist
o The condylar elements of articulator must be adjusted to simulate as
closely as possible the condylar paths of patient
o Average condylar guidance is about 25-30 degree

Incisal Guidance
134
Defined as
1. the inﬂuence of the contacting surfaces of the
mandibular and maxillary anterior teeth on
mandibular movements;
2. the inﬂuences of the contacting surfaces of the
guide pin and guide table on articulator
movements – GPT 9

135
• It is usually expressed in degrees of angulation from the horizontal
plane by a line drawn in sagittal plane between incisal edges of upper
and lower incisor teeth when closed in centric occlusion.

136
o Greater the vertical overlap of anterior teeth  steeper the incisal
guidance and on forward movement greater separation of posterior
teeth
o Greater the horizontal overlap of anterior teeth  flat anterior
guidance
o Steep incisal guidance  steep cusps, steep occlusal plane, or steep
compensatory curve in order to achieve
OCCLUSAL BALANCE

137
o As steep inclined planes are detrimental to the stability and equilibrium
of denture, it should be as flat as esthetics and phonetics will permit.
o On average it is about 10-12 degree.

Orientation Of Occlusal Plane
138
o It is established in the anterior by the height of lower cuspid, which is
nearly coincident with the commissure of the mouth.
o Posterior - by the height of retromolar pad. It is also related to ala-tragus
line.

139
o This plane is assumed to pass through 3 dental landmark central incisal
point and summit of mesio-buccal cusp of last molar on either side.
o It is transferred to articulator with help of facebow.

140
o Steep increase in inclination of occlusal
plane will result in movement of upper
denture backward and lower denture
forward during function.
o Decrease in inclination will result in
opposite of above movement

4.Compensating Curves
141
o It refers to antero-posterior and lateral curve
produced in the alignment and arrangement
of occluding surfaces of the teeth.
o They are the artificial components of the
curve of Spee and Monsoon which are
found in the natural dentition.

142
o It compensates for opening - called as “CHRISTENSEN’S phenomenon”
that occurs in posterior region when protrusive movements are made.

Compensating curves:
143 ANTERO -POSTERIOR MEDIO-LATERAL CURVE

Cuspal Inclination
144
o It refers to the angle between the cuspal
incline and the horizontal cuspal plane.
o The inclination of the cusp is made
steeper  when the distal end of the
lower tooth is set higher than the mesial
end

145
o The cuspal inclination can be reduced  when the distal end of the
lower teeth is set lower than the mesial end
o Similar adjustment can be made in the inclination of buccal and lingual
cusps when the buccolingual long axis of the teeth are tipped.
o Thus tipping the teeth can produce compensatory curve and make the
effective height of the cusp greater or less.

Influence of Condylar Guidance & Incisal Guidance on
Cuspal Inclination:
146
o Closer the tooth is located to one or other guidance, the more
influence that guidance has on the angle of inclination of its
cusps.

147
o For balance to be achieved, the cuspal
inclination should be parallel with the
mandibular path. (In theory the cuspal
angle required to obtain balance in
protrusion is obtained as follows)

148
o The rotational center of the mandibular path is determined by lines drawn
at right angles from the center of the incisal guide table and from the
condylar track.
o From this intersection curves are traced through the occlusal plane.

• The occlusal plane can
be set at different levels
and each radius
determines the position
of the teeth for balance.
149

• If the incisal guidance is steeper
than the condylar inclination the
intersection of the perpendiculars
is below the occlusal plane and
balanced occlusion is not
possible.
150

Lateral movement
151
o Posterior teeth  parallel to the
path of mandibular movement
o The center of rotation is
established  Lines drawn right
angles to the buccal inclines of
mandibular lingual cusp on
working side and another at right
angles to the lingual surface of
mandibular buccal cusp on the
balancing side. Establishment of center of rotation on lateral moveme

152
o All inclines involved in this lateral position must be on the curves of the
arcs drawn from this rotational center.

Factors Affecting Protrusive Balance
153
o Inclination of the condylar path on the articulator as recorded from
patient
o Inclination of the incisal guidance taken from the patient
o Inclination of the plane of occlusion set to physiological factors
o Compensating curve set to harmonize condylar and incisal guidance
o Control of cusp height and tooth inclination

Factors Affecting Lateral Balance
154
o Condylar inclination on the balancing side
o Inclination of the incisal guidance and cuspid lift
o Inclination of plane of occlusion on balancing and working side
o Compensating curve on balancing and working side
o Bennett side shift on working side
o Buccal cusp height or inclination on balancing side
o Lingual cusp height or inclination on the working side

Arranging teeth for balanced occlusion
157
Programming of articulator:
o The centric relation record is the first essential record that is used
to mount casts on the articulator.
o So the articulator is programmed already in two aspects i.e. casts
are related together in CR as well as the selected vertical
dimension of occlusion.
o Now the articulator is to be adjusted for condylar and incisal
elements.

158
Condylar elements:
o As the mandible moves forward in protrusive excursions the
condyles typically move downward separating posterior teeth.
o Therefore, the amount by which the posterior teeth are separated
is a measure of the amount the condyles move downward as they
move forward.
o An interocclusal (protrusive) record that captures that posterior
separation between the occlusal rims in patient’s mouth can be
replaced between the rims on the articulator.

159
Following the relationship of the mandibular cast
to the maxillary cast by means of centric relation
interocclusal record, the horizontal condylar
inclination must be determined.
o This is accomplished by means of protrusive
interocclusal record.
o The patient should protrude approximately
6mm
o The horizontal condylar guidance is adjusted
until maxillary cast seats into protrusive
interocclusal records.

160
o These condylar settings are used to simulate lateral horizontal
condylar guidance.
o The amount of Bennett movement is calculated by the horizontal
condylar settings by Hanau’s equation:
o Bennett angle (L) = H/8 + 12, where H = HCG

161
Incisal elements:
• The adjustments are made along the frontal and the sagittal plane in
the articulator to compensate for the amount of horizontal overlap
incorporated in the anterior arrangement of teeth.

162
• The setting of the incisal guide table protects the anterior teeth from
dislodgement when arranging the posterior teeth.
• Sagittal inclination  bringing the central incisor into end to end
relation
• Frontal adjustment  cuspid into end to end relation

Setting sagittal inclination
of incisal guide table
Setting frontal inclination
of incisal guide table
163

ARRANGING TEETH IN BALANCED OCCLUSION
164
Balancing eccentric occlusions:
• When the dentures are moved out of centric occlusion  eccentric
occlusion, if there is contact at three widely separated points, then the
occlusion is said to be balanced.

165
• The eccentric occlusion usually considered are the
 Protrusive occlusion  anterior teeth edge to edge
 Right and left lateral occlusion  teeth of working side in buccal
cusp to buccal cusp inter digital contact

166
• In the protrusive occlusion there should be balancing contacts
between all the posterior teeth (at least between the last molars).

167
• In lateral occlusion there should be balancing contacts between all the
posterior teeth of the balancing side (At least between the last molars).

168
• The amount of vertical overlap of the incisors which will be provided
with a given amount of horizontal overlap determines the slope of
incisal guide table.
• The arrangement of anterior teeth should be checked by phonetics and
esthetics and incisal guide table can be adjusted accordingly.

Arranging the posterior teeth:
169
Mandibular premolars:
• Central fossae in line with the canine retromolar pad
reference line
• Occlusal plane : mandibular anterior teeth
Mandibular molars
• First molar  Distal cusp 0.5mm above the occlusal plane
• Buccal and lingual cusps at same height to make transverse
plane horizontal

170
Second molar: Continuous cuspal elevation of compensatory curve.
• The imaginary extension should be parallel to the condylar inclination
• Central fossae aligned  canine retromolar pad reference points

171
• Maxillary premolar:
• Proper position and static cusp contact in centric occlusion
• Checked and refined for dynamic cusp contacts in working,
balancing and protrusive movements

172
First molar:
• Mesiolingual cusp  central fossa of lower 1st molar
• Distolingual cusp between marginal ridges of mandibular 1st and 2nd
molars

173
Second molar:
• Slight more buccal tilt
• Mesiolingual cusp  central fossa of lower 2nd molar
Progressive raising of buccal cusps

SELECTIVE GRINDING
175
o The modification of the occlusal forms of the teeth with the intent
of equilibrating occlusal stress, producing simultaneous occlusal
contacts/ harmonizing cuspal relations.
o Rationale:
1) Eliminate occlusal interferences and to achieve occlusal harmony

176
2) Contacts in harmony with TMJ and neuromuscular system
3) Failure to achieve it
-Soreness
-Loss of supporting bone
-TMJ problems

177
• Principles :
1. Eliminate interlocking transverse ridges
2. Functional cusp not subjected to selective grinding
3. Functional cusp inclines can be reduced but not the cusp

178
Steps at which grinding is performed:
1. At the time of teeth arrangement
2. Lab remount procedures
3. Clinical remount procedures

At the time of teeth arrangement
179
Selective grinding for centric contacts
o After the complete arrangement of teeth, place an articulating paper and
tap the articulator
o Only the lower central fossa or marginal ridges should be ground not the
upper lingual cusps

180
o If any upper buccal cusps or inclines are in contact, they should be
ground out of contact
o Final result: Stable contact with all upper lingual cusps in the common
lower central fossa

181
Selective grinding for working and balancing contacts:
• Working side  Upper lingual cusp contacts lower lingual cusp
• Balancing side  Upper lingual cusp contacts lower buccal cusp

182
• Grind the heavily marked contacts – by selective spot grinding the
premature inclines  until smooth harmonious multiple contacts will
occur
• Method:
• Articulating paper placed bilaterally on posterior teeth
• Gentle pressure on upper member of articulator
• Duplicate lateral excursion

183
Selective grinding for the protrusive contacts
o Maxillary lingual cusp gliding over the distal lingual cusp of the
mandibular teeth
o All the premature contacts are gently ground off
o If anterior teeth prematurity  it can be modified keeping esthetics in
mind

To be discussed:
184
o CONCEPTS OF OCCLUSION  NON-BALANCED ARTICULATION
o REVIEW OF LITERATURE
o CONCLUSION
o REFERENCES

Nonbalanced articulation
185
• Various concepts proposed to attain nonbalanced articulation.

Pound’s concept
186
o Maxillary posterior teeth should have sharp palatal cusps  opposing
widened central fossae of the mandibular posterior teeth
o Teeth should have gold occlusal inlays to maintain vertical dimension at
occlusion
o Accurate retentive denture bases are a requirement in this concept
Beck HO. Occlusion as related to complete removable prosthodontics. J Prosthet Dent
1972;27:246-56

Aull’s concept
187
Features:
o Artificial maxillary posterior should have 33° cusp form teeth
with full gold occlusal surface
o Anterior teeth arranged to meet the requirements of phonetic
values
1972;27:246-56

188
o Characteristic of this concept:
 Recording pantographic tracing  transferring it to articulator  to
eliminate deflective contacts in the posterior arrangement
o Accurate retentive denture bases are a requirement in this concept

Hardy’s concept
189
Features
o Nonanatomic maxillary and mandibular posterior teeth are arranged in a
flat plane with a minimum overbite
o Masticatory forces are directed toward the ridge bilaterally in centric
occlusion
1972;27:246-56

Sear’s concept
190
Features:
o Occlusal pivots were introduced by Sear
o Pivots place the mandible in equilibrium by maintaining the occlusal
load in the molar regions
o Occlusal contact forces are also reduced in the anterior region of the
residual ridges
1972;27:246-56

Kurth’s concept
191
Features:
o Artificial posterior teeth arranged incorporating the reverse lateral curve
o This concept utilizes a posterior tooth blocks in series of four teeth
which were arranged on a flat occlusal plane with a reverse lateral curve
and posterior ramp
1972;27:246-56

LINGUALISED OCCLUSION
192
o In 1927, Gysi introduced the concept of lingualized
articulation.
o In 1941, Payne reported on Farmer’s posterior setup that used
30° cusp teeth that were selectively reshaped to fulfill the
concept of lingualized articulation and meet the individual
requirements of edentulous patients.
Becker CM, Swoope CC, Guckes AD. Lingualized occlusion for removable prosthodontics. J Prosthet Dent 1977;38:601-6

193
o In effect, the occlusion is lingualized by
• the elimination of contacts on the buccal cusps
• the anteroposterior arrangement of lower posterior teeth
• so that their lingual surfaces are on or within the lingual side of a
triangle from the mesial area of the lower cuspid to the sides of the
retromolar pad

194
A monoplane occlusal scheme limits
esthetic results in the premolar region.
A lingualized occlusion provides
improved esthetics in the premolar

Principles OF LINGUALIZED OCCLUSION
195
o Anatomic posterior teeth are used for maxillary denture. Tooth
form with prominent lingual form are used.
o Nonanatomic/semianatomic teeth are used for mandibular
denture. A narrow occlusal table is preferred when severe
resorption has occurred.
o Selective grinding smoothens the central fossa of the
mandibular teeth.

196
A Carborundum stone is used to
recontour the mandibular teeth
Selective grinding of mandibular tooth
forms is needed to create a slight concavity
in the occlusal surface. Left - shallow
cusp form; Right - 0 degree cusp form

197
o Upper lingual cusp occlude in mandibular central fossa. The
upper posterior teeth are rotated slightly to avoid all contact of
buccal cusp.
o Balancing and working contacts should occur only on the
maxillary lingual cusp.

Selective grinding of maxillary buccal cusp
Reduces lateral movement of the lower denture by placing
occlusal forces more lingual to & towards the center of
mandibular teeth
198

199
o Lingualized occlusion is developed to maintain the food-penetration
advantages of the anatomic form while maintaining the mechanical
freedom of the nonanatomic form.
o The lingualized concept utilizes
• anatomic teeth  maxillary denture
• modified nonanatomic or semi anatomic teeth  mandibular
denture

200
Indications:
• High priority on esthetics but a nonanatomic occlusal scheme is
indicated
• Severe residual ridge resorption
• Class II jaw relationship
• Flabby supporting tissue
• When a complete denture opposes a removable partial denture

201
Advantages:
• Both the anatomic and nonanatomic forms are retained
• Cusp form is more esthetic compared to nonanatomic tooth form
• Good penetration of the food bolus is possible
• Bilateral balanced occlusion can be obtained for a region around
centric relation
• Vertical forces are centralized on the mandibular teeth

Versatility of lingualised occlusion makes it a
powerful tool
Characteristic Balanced Lingualised Non-Balanced
1. Better esthetics + + -
2. Ease of penetration
(decreased vertical
stresses)
+ + -
3. Simpler technique - + +
202

Characteristic Balanced Lingualised Non-Balanced
4. Decreased lateral
forces
- + +
5. Ease of
adjustment
- + +
6. Good for class II
and Class III
relations
- + +
7. Good stability by
force
centralization
- + +
203

Organic occlusion
204
o In this concept, the anterior teeth are arranged according to the
requirements of esthetics and phonetics.
o Extreme vertical overlaps producing cuspid guidance are frequently
used, resulting in disocclusion of the posterior teeth away from centric
occlusion.

205
o Characteristic of this concept is:
• Use of pantographic tracings  transfer of these recordings to an
instrument  to eliminate all potential deflective contacts in the
arrangement of posterior teeth

206
• This occlusion is based on the concept that
• muscles and joint determines the mandibular position
• without tooth guidance
• the teeth in the function should always be passive to the parts of the
mandibular movements

207
In organic occlusion
o The posterior teeth  protect the anterior teeth in the centric occlusion
position

208
o The maxillary incisors should have sufficient vertical overlap to provide
separation of the posterior teeth when the incisors are in edge-to-edge
relation
o In lateral mandibular position outside the masticatory movements  the
cuspids should prevent contacts on all other teeth

Monoplane Occlusion
209
o Jones advocated monoplane articulation in 1972
o In this concept, a nonanatomic occlusal scheme is used with a
few specific modifications
o Nonanatomic teeth have no cusp inclines; therefore
balancing contacts must be obtained by other means.
Brudvik JS, Wormley JH. A method of developing monoplane occlusions. J ProsthetDent 1968;19:573-80

210
o One method is to arrange teeth (maxillary and mandibular) to a flat
plane with no overbite. The plane can be positioned to prevent
disturbing protrusive interferences, but it may compromise phonetics
and esthetics.
o Another method is to incline the mandibular second molar to provide
contact with the maxillary denture in all excursions. (Not Monplane)

211
o The maxillary second molars are similarly inclined but left out
of centric contact.
o The inclined second molars provide balancing contacts in
protrusive movements but may lack balancing contacts in
lateral excursions.

212
o An improvement on the inclined molar technique is the use of
customized balancing ramps placed posterior to the most distal
mandibular molars.

213
o The maxillary posterior teeth are arranged first, and the occlusal plane
must fulfill certain requirements.
• Should evenly divide the space between the upper and lower ridges
• Be parallel to the mean denture base foundation
• Fall at the junction of the upper and middle thirds of the retromolar
pads

As the patient moves the mandible from centric relation to
protrusive or lateral position  smooth contact anteriorly on the
teeth  posteriorly on the ramp
A balancing contact
B working contact
C protrusive contact
214

215
Indications:
o Flat ridges
o Knife edge ridges
o Large inter-ridge space
o Poor neuromuscular coordination

216
Advantages:
o Preservation of structure of basal seat
o Simplicity of technique involved
o Good for patients with cross-bite or class 3 relationships and
especially for patient with class 2 relationships who have an
extremely long functional path

217
Disadvantages:
o Not esthetic
o Reported as less efficient in chewing tests

Neutrocentric concept
218
o In 1954, De van formalized guidelines for using “Neutrocentric
concepts”
o The term “neutrocentric” is suggested to denote a concept
embodying two key objectives in the making of a denture:
1. Neutralization of inclines
2. Centralization of occlusal forces acting on the denture foundation
De Van MM. The concept of neutrocentric occlusion as related to denture stability. J Am Dent Assoc

219
o In order to attain these objectives, it may be necessary
• to reduce the size and the number of teeth
• to abandon attempts to secure balancing contacts in eccentric
positions beyond the range of the “masticatory stroke”

220
o Dentures made in accordance with this concept have proved
superior to those copying the natural teeth in position, propor-
tion, pitch, form and number of teeth.
o The dentures thus made achieve (1) surprisingly satisfactory
preservation of ridge bone and (2) good appearance, adequate
speech and mastication.

221
o However, this concept should not be identified with that of the
advocates of nonanatomic teeth, who merely dispense with cuspation.
o Because it is dangerous to discard cusps without neutralizing other
factors of articulation; that is, (1) orientation of the occlusal plane, (2)
compensating curve and (3) incisal guidance.

222
o There is only one factor of articulation which cannot be
neutralized – condylar guidance, but which can be
circumvented by a plan involving the neutrocentric concept.
o If the patient can be persuaded to avoid incising with artificial
teeth, there is no need to be concerned with the sagittal
condylar incline.
o When incision is avoided and no projections exist above or
below the occlusal plane, the condylar inclination on the
articulator may be set at zero.

223
• There are five factors involved in the relation of the teeth to the
denture foundations for denture stability, which are
o Position
o Proportion
o Pitch
o Form
o Number

224
Position
o Arrange the teeth in central position in reference to the foundation as the
tongue will allow, in order to provide greater stability for the denture.

225
Proportion
o Reduced tooth width to 40% of original tooth proportion
 Reduces the vertical stresses on the ridge
 Horizontal stresses also reduced due to the friction between opposing
surfaces was decreased
 Forces more centralized without encroachment on the tongue space

226
Pitch
o Tooth pitch (inclination, tilt) corrected by placing the occlusal
plane parallel to the underlying ridges and midway between
them
o This positioning directs the forces perpendicular to the mean
osseous foundation plane
o There was no compensating curve and no incisal guidance

227
Form
o Tooth form modified using flat teeth with no deflecting inclines
o Reduced destructive lateral forces and the masticatory forces directed
perpendicular to the support
o All contacts in a single plane with no projections above or below the
plane to interfere with the mandibular movements

228
Number
o Posterior teeth reduced in number from 8  6
o Decreased magnitude of the occlusal force and centralized to the second
premolar and first molar area

229
Advantages:
o Simple and requires less precise records
o Ideal for a patient who has resorbed ridges with mobile tissue
o By removing inclines  lateral forces are reduced
o Easier to adjust
o Provides an area of closure and does not lock the mandible into a single
position

230
o Centric occlusion – centric relation discrepancy introduced by the
denture settling would tend to be less destructive because of the
unlocked nature of the occlusion
o Especially indicated in class II (retrognathic) and class III (Prognathic)
crossbite cases

231
Disadvantages:
o Unesthetic as there is no incisal overlap and no posterior cusps
o Impaired mastication efficiency

Physiologically generated occlusion
232
o Mehringer developed physiologically generated occlusion to harmonize
the complete denture occlusion, neuromuscular system and the
temporomandibular joint.
o The complete denture fabrication is preceded till try in and processing of
only maxillary denture is done.

233
o The patient is asked to make chewing and swallowing movements,
which creates functionally generated paths
o Lower teeth are arranged according to maxillary cast over the generated
path

Lineal occlusion
234
o A line of occlusal contacts in one dental arch opposing a flat occlusal
table in the other dental arch has the potential of creating the smallest
lateral component of force against the denture bases.
o Since the area of contact is minimal, the frictional resistance is reduced.
Gronas DG. Lineal occlusion concepts for complete dentures. J Prosthet Dent
1974;32:122-129

235
• COMBINATIONS OF OCCLUSAL FORMS USED FOR
LINEAL OCCLUSION:
• Maxillary - nonanatomic porcelain teeth;
mandibular - porcelain lineal teeth
• Maxillary - plastic teeth (modified); mandibular - plastic lineal
teeth
• Maxillary - nonanatomic plastic teeth; mandibular - porcelain
lineal teeth
• Maxillary - Anatomic Porcelain Teeth;
Mandibular - Nonanatomic Plastic Teeth

Linear occlusion
236
o The occlusal arrangement of artificial teeth, as viewed
in the horizontal plane,
• wherein the masticatory surfaces of the mandibular
posterior artificial teeth have a straight, long, narrow
occlusal form resembling that of a line, usually
articulating with opposing monoplane teeth.
Weinberg LA. Temporomandibular joint function and its effect on concepts of occlusion. J Prosthet Dent 1976;35:553-
66

237
• Teeth are arranged on a flat plane, which extends from the tip of
maxillary central incisors to the top of the retromolar papilla.

238
o The posterior teeth used are nonanatomic with mandibular blade form of
teeth.
o They exhibit bilateral fulcrum of protrusive stability – on protrusion,
blade form of mandibular second molar contacts maxillary first
premolar bilaterally and prevent anterior rotational contact.

Canine – Guided Occlusion for Complete denture
239
o Ramfjord & Ash (1983) refer to the fact that the 'balancing side occlusal
interferences' have a very disturbing influence on the function of the
masticatory system and often trigger bruxism and associated pain in
both muscles and temporomandibular joints.
I. Grunert. Masseter and temporalis surface electromyography in patients wearing complete dentures comparing anterior and posterior occlusal
concepts — A pilot Study. Journal of Oral Rehabilitation, 1994, Volume 21. pages 337-347

240
o A number of investigations showed decreased muscle activity during
lateral movements of the mandible while the canines were in contact
without any additional contact of the posterior teeth (Dahlstrom, 1989).
This confirmed the 'cuspid protective mechanism concept' of D'Amico
(1958).

241
o During parafunction, the activity of masticatory muscles will be lower
with complete dentures providing anterior-canine guidance than with
dentures offering a balanced occlusion.
o This favours the use of anteriorly guided dentures to help prevent the
development of craniomandibular dysfunction problems, high muscle
activity, muscle pain, temporomandlibular joint disorders, ridge
resorption.

243
Complete Denture Occlusion: An Evidence-Based Approach. A
Farias-Neto, A Carreiro. Journal of Prosthodontics 00 (2012) 1–4.
 Study involved an extensive search for randomized controlled
clinical trials comparing bilateral balanced and canine-guided
dentures.
 Studies were identiﬁed by searching electronic databases
(PubMed/MEDLINE, ISI Web of Science, LILACS, and BBD)
using keywords “denture” and “occlusion”

244
 The minimum inclusion requirements were (1) randomized controlled
trials with patients of any age wearing both maxillary and mandibular
conventional complete dentures (CDs), (2) comparison between bilateral
balanced and canine-guided dentures, and (3) assessment of masticatory
function and/or patients’ satisfaction.

245
 Out of the 7 shortlisted studies, which measured the chewing
efficiency and patient satisfaction
 4 showed no significant difference between balanced and canine-
guided occlusion
 2 studies suggested canine guided occlusion to be better than
balanced occlusion
 1 study suggested balanced occlusion to be better than canine guided
occlusion

246
Occlusal designs on masticatory ability and patient
satisfaction with complete denture: A systematic review. K
Zhao, Q Mai, X Wang, W Yang, L Zhao. Journal of dentistry
41(2013)1036 – 1042.
 Using a various key words, an electronic search of clinical
trials published in English and Chinese literature was
performed from four databases: Medline/PubMed, EMBASE,
Cochrane Library and CBM.
 Furthermore, a manual searching of the relevant journals and
the bibliographies of reviews was performed.

247
 General satisfaction, masticatory ability, retention and stability were
major criteria for the evaluation of the outcomes.
 Review concluded that lingualized occlusion and canine-guided
occlusion can be successfully applied in the fabrication of complete
dentures.

248
 Canine guided occlusion has also been shown to be satisfactory.
 More well-controlled randomized trials are needed regarding canine-
guided occlusion and the relationship between alveolar ridge resorption,
different occlusal schemes and patient satisfaction.
 The conventional prosthodontic wisdom that complete dentures require a
balanced occlusal design is not supported by the included literature.

249
• Masticatory Efficiency in Denture Wearers with Bilateral
Balanced Occlusion and Canine Guidance. A FARIAS NETO,
W MESTRINER, A CARREIRO. Braz Dent J (2010) 21(2):
165-169.
 A double-blinded controlled crossover clinical trial was
conducted
 Sample size - 24 edentulous patients who wore sets of complete
dentures with both occlusal concepts during equal periods of 3
months
 Objective data collected through the masticatory efficiency test
performed by the colorimetric method with the beads

250
 Subjective data were recorded by patient's ratings of their chewing
function.
 No significant statistical difference was found for masticatory efficiency
(p=0.095) between the two occlusal concepts studied.
 The results suggest that bilateral balanced occlusion does not improve
the masticatory efficiency in complete denture wearers.

251
• Comparisons of Patient Satisfaction Levels with Complete
Dentures of Different Occlusions: A Randomized Clinical
Trial. M Shirani, R Mosharraf, M Shirany. Journal of
Prosthodontics 23 (2014) 259–266.
 Three sets of complete dentures were made for each of 15
patients (mean age = 58.87 ± 15.02 years).
 They received (1) fully bilateral balanced occlusion (BBO), (2)
lingualized occlusion, and (3) buccalized occlusion (BO)
denture sets in random order.

252
 After wearing each set for 6 weeks, patient satisfaction was assessed
using a 19-item version of the Oral Health Impact Proﬁle for Edentulous
Patients (OHIP-EDENT)
 Each question was scored on a 1 to 5 scale for patients’ problems with
dentures (for these ordinal variables, 1 = “never” and 5 = “very often”).

253
 Results showed in patients within ideal maxillomandibular relationships
with mild and moderately resorbed ridges, BBO scored significantly
higher for uncomfortable eating and avoiding particular foods than LO.
 Also BBO scored significantly higher for avoiding particular foods and
physical disability than BO.
 Furthermore, BBO scored significantly lower for uncomfortable
dentures than LO.

254
In Vivo Comparison of the Masticatory Efﬁciency of Artiﬁcial
Teeth with Two Different Cusp Heights in Complete Dentures:
A Preliminary Study. W Barbosa, C Legami, P Uehara, R
Furuyama at al. Journal of Prosthodontics 00 (2015) 1–5.
 Two teeth compared:
 Heraeus Premium teeth – 30 degree cusp with greater height
– 2.39mm
 Dentsply Biotone teeth -33 degree cusp with lesser height -
1.67 mm
 Sixteen complete denture wearers were given complete
dentures with Heraeus Premium teeth.

255
 Fifteen days after denture installation, a first masticatory efficiency test
was performed with Optocal.
 A new pair of complete dentures with Dentsply Biotone teeth was then
given to each participant to replace the first set.
 Fifteen days after installation of the dentures with Biotone teeth, a
second masticatory efficiency test was performed with Optocal.

256
 On both tests, the comminuted material was treated and sieved through a
stack of sieves under vibration. The content of each sieve was weighed,
and the obtained data were tabulated.
 Results showed no differences in the masticatory efﬁciency of the
complete denture sets using teeth with the two cusp heights.

257
Different Occlusal Schemes in a Persistent Protruding
Complete Denture Wearer. C Legami, D Lopes, A Edson, M
Nakamae at al. Journal of Prosthodontics 00 (2016) 1–5.
 This report presents an alternative for persistent involuntary
protruding complete denture wearers through the use of
artificial teeth with higher cusps.
 Due to an old and worn pair of complete dentures, the patient
had the habit of protruding.

258
 New dentures were made with artificial teeth (Biotone) and in the trial
session, the patient would still protrude.

259
 A new set was made with artificial teeth (Premium), which present
higher cusps.

260
 With these dentures, the involuntary protrusion did not occur.
 From the delivery to the follow-up sessions, the patient stopped
protruding.

CONCLUSION
261
o To date, none of the occlusal patterns has scientifically been proven the
best.
o The first concern is for the health and preservation of the supporting
structures.
o The operator needs to first apply all of the factors that favor the
stability of the base, and then design the occlusion to function
optimally in relation to the forces of mastication.

262
o Begin the occlusal scheme at a repeatable and physiologically
acceptable mandibular position and then give it freedom for the
variances inherent in muscle function, eating habits and foundation
changes.
o Occlusal designs can be varied according to the dentist’s preference and
can still control the force so that the loss of tissue attributed to occlusion
can be minimized.

References:
263
 Winkler S. Essentials of complete denture prosthodontics. 2nd ed. AITBs Publishers,
Delhi: 2000
 Rahn AO, Heartwell CM. Textbook of Complete Dentures. 5th ed. Philadelphia: Lea
and Febiger; 1993
 Zarb GA, Bolender CL. Prosthodontic Treatment for Edentulous Patients. 12th ed.
New Delhi: Mosby; 2004.
 The glossary of prosthodontic terms. 9th ed. J Prosthet Dent 2017.
 Lang BR. Complete denture occlusion. Dent Clin North Am 2004; 48:641-65.

References:
264
 Beck HO. Occlusion as related to complete removable prosthodontics. J Prosthet
Dent 1972;27:246-62.
 Levin B. A reevaluation of Hanau’s Laws of Articulation and the Hanau Quint. J
Prosthet Dent 1978;39:254-8.
 Sheppard IM, Sheppard SM. Denture occlusion. J Prosthet Dent 1968;20:307-18.
 Becker CM, Swoope CC, Guckes AD. Lingualized occlusion for removable
prosthodontics. J Prosthet Dent 1977;38:601-608.
 Brudvik JS, Wormley JH. A method of developing monoplane occlusions. J
ProsthetDent 1968;19:573-80.

References:
265
 De Van MM. The concept of neutrocentric occlusion as related to denture
stability. J Am Dent Assoc 1954;48:165-169.
 Mehringer JE. Physiologically generated occlusion. J Prosthet Dent
1973;30:373-79.
 Gronas DG. Lineal occlusion concepts for complete dentures. J Prosthet Dent
1974;32:122-129.
 Weinberg LA. Temporomandibular joint function and its effect on concepts of
occlusion. J Prosthet Dent 1976;35:553-66.
 I. Grunert. Masseter and temporalis surface electromyography in patients
wearing complete dentures comparing anterior and posterior occlusal concepts
— A pilot Study. Journal of Oral Rehabilitation, 1994, Volume 21. pages 337-
347

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