3. • INTRODUCTION
• DEFINITIONS
• REVIEW OF LITERATURE
• EVOLUTION OF OCCLUSION
• NATURAL OCCLUSION&ARTIFICIAL
OCCLUSION
• REQUIREMENTS OF ‘C D ’OCCLUSION
• AXIMS FOR ARTIFICIAL OCCLUSION
• POSTERIOR TOOTH FORMS
• CONCEPTS OF OCCLUSION
• CONCLUSION
www.indiandentalacademy.com
4. Occlusion is any contact between the
incising or masticatory surfaces of upper
and lower teeth.
Most important subject in all branches
of dentistry.
Articulation
www.indiandentalacademy.com
5. • Importance of occlusion
1 . Vertical & lateral components of
occlusal stresses
2 . In case of F P D’s harmonious
occlusion
3 . Inharmonious occlusion
4 . Repeated fracture of facings
www.indiandentalacademy.com
7. OCCLUSION ( G P T 8 )
“ The static relationship between
incising or masticating surfaces of the
maxillary or mandibular teeth or tooth
analogues . ”
www.indiandentalacademy.com
8. CENTRIC
OCCLUSION
“ The occlusion of
opposing teeth
when the
mandible is in
centric relation .
This may or may
not coincide with
the maximal
inter cuspation ”
ECCENTRIC
OCCLUSION
“ An occlusion
other than centric
occlusion ”
www.indiandentalacademy.com
9. Articulation
“ the static and dynamic contact
relationship between the occlusal
surfaces of teeth during function . ”
www.indiandentalacademy.com
10. Balanced occlusion
“ The bilateral , simultaneous ,
anterior , and posterior occlusal contact
of teeth in centric and eccentric
positions ”
www.indiandentalacademy.com
11. Maximum intercuspation
“ the complete intercuspation of
opposing teeth independent of condylar
position , sometimes referred to as best
fit of teeth regardless of the condylar
position ”
www.indiandentalacademy.com
12. Lingualised articulation ( S. Howard
payne in 1941 )
“ this form of denture occlusion
articulates the maxillary lingual cusps
with the mandibular occlusal surfaces ,
in centric working and non working
mandibular positions . ”
www.indiandentalacademy.com
13. Monoplane occlusion
“ an occlusal arrangement where in the
posterior teeth have masticatory
surfaces that lack any cuspal height ”
www.indiandentalacademy.com
15. • BALANCED ARTICULATION by ALFRED
GYSI
1.33° cusp form
2.30° cusp form by
PILKINGTON AND TURNER
www.indiandentalacademy.com
16. In this concept ,a non anatomic occlusal
scheme is used with a few
modifications.
First one is articulator used
Second one is arrangement of maxillary
and mandibular teeth without any
vertical overlap
After introduction of 0°teeth posterior
teeth are positioned on a flat plane.
Anterior teeth are positioned with a
horizontal and vertical overlap
www.indiandentalacademy.com
17. • He used 30° cusp teeth that were
selectively reshaped to fulfill the
concept of lingualised occlusion
• L O allows adaptation to different
types of ridges , greater masticatory
efficiency , elimination of lateral
interferences
• L O based on the maxillary lingual cusp
functioning as the main supporting
cusp in harmony with the occlusal
surfaces of the lower teeth.
www.indiandentalacademy.com
18. • According to this concept the stability of
mandibular prosthesis can be improved by
using the linear occlusion and steeper
occlusal plane.
• Linear ( non interceptive ) occlusion
consists of following requirements
1 . Zero degree teeth are opposed by
bladed teeth
2 . Mandibular teeth are set to a flat
occlusal plane
3 . There is no anterior tooth interference
to protrusive or lateral movement.
www.indiandentalacademy.com
19. Study on a clinical trial comparing
anatomic, lingualised , and zero degree
posterior occlusal forms for complete
dentures.
concluded that , lingualised posterior
occlusal forms were superior in reducing
sore spots , ability to eat , meal
interruptions compared to 0° posterior
occlusion.
www.indiandentalacademy.com
20. BONWILL’S “ Equilateral triangular concept ”
He believed that articulation of teeth guides the mandible
during function.
He postulated that the distance from incisal edges of
lower incisors to each condyle is 4 inches ( 10 cm ) and
the distance between each condyle is also 4 inches.
www.indiandentalacademy.com
21. Ferdinand Graf Von Spee ( 1890 )
There is a relationship between the curved
arrangements of the occlusal planes of
natural teeth and the corresponding curves
of the condylar paths.
He described the forward movement of
mandible in sagittal plane.
Concentric arcs shows nature of protrusive
movement of mandible.
Total contacts of molar masticatory
surfaces lies on same arc of a circle.
Posteriorly arc touches most
anterior point of condyle
www.indiandentalacademy.com
23. Axis of these arcs lies at the level of
horizontal mid orbital plane.
Steeper the path of condyle , more
pronounced the tooth curve would be
because both have same radius.
www.indiandentalacademy.com
24. “ Carl christensen ”observed the
opening of posterior teeth in mandibular
protrusion .
First to describe an intra oral method of
recording a static protrusive record to
determine condylar inclination.
Ulf Posselt.
www.indiandentalacademy.com
25. George S Monson in 1916
It was based on the concept that the
mandibular teeth move over the
occlusal surfaces of maxillary teeth as
over the external surface of a segment
of an 8 inch sphere and the radius of a
sphere is located in the region of crista
galli
www.indiandentalacademy.com
28. According to this concept if 2 equilateral
triangles ( Bonwill) were placed back to
back they would share a common base
that represented the condylar axis.
Vertex of anterior triangle incisor
point
posterior triangle external
occipital protruberance
www.indiandentalacademy.com
29. Reverse curve will stabilize the lower
denture
Based on observation that occlusion of
dentures and natural dentition were in a
reverse curve fashion i.e. maxillary lingual
and mandibular buccal cusps .
Main draw back
www.indiandentalacademy.com
30. Max pleasure in 1937 introduced “
pleasure curve ” which advocates “ anti
-monson curve ” exept for second
molars.
In pleasure curve reverse curve is used
in bicuspid area for lever balance, flat
occlusion is set in first molar area and a
spherical scheme in second molar area.
www.indiandentalacademy.com
32. Technique involve restoring mandibular
posterior occlusion to a 4 inch sphere.
Maxillary posterior occlusion was fabricated
to mandibular occlusal form by using
maxillary anterior teeth as guide.
According to Schuyler
1.balancing side contacts were eliminated
2.importance of incisal guidance was
elevated
3.concept of long centric was proposed in
which centric occlusion is thought as an
area of contact rather than a point contact.
www.indiandentalacademy.com
33. Condyles were the determinants of
occlusal schemes, and the side shift of
condyles would greatly affect cuspal
position.
Hinge axis was located by rotational
centers of condyles
3-dimensional envelope of motion of
condyles are recorded by pantographic
tracings
Maximum inter cuspation of teeth when
the condyles are in their hinge position
www.indiandentalacademy.com
35. Natural
1.Teeth retained by
periodontal tissues
2. Teeth receive
individual pressures
of occlusion.
3.malocclusion-
uneventfull for years.
4. Non vertical forces
effect only the teeth
involved and
tolerated.
5.Incising
Artificial
1.Allteeth are on bases
seated on slippery
tissues.
2.Teeth move as a unit
3.Malocclusion causes
immediate response.
4.Involves all teeth on
base and traumatic.
5. Incising affects all
teeth on base.
www.indiandentalacademy.com
36. Natural
6.Second molar –
masticating area
7.Bilateral balance
is rarely found
8.Force necessory
to masticate
food 5-175
pounds.
Artificial
6. Cuases tilting
of bases
( inclined plane
effect )
7.Bilateral balance
is necessary for
stability
8.11.7 pounds
www.indiandentalacademy.com
37. Stability of occlusion
Balanced occlusal contacts
Unlocking of cusps mesio distally
Horizontal force controlled by bucco
lingual cusp height reduction
Functional lever balance
Cutting, penetrating, shearing
Anterior incisal clearance
Minimum occlusal contact area
Sharp ridges or cusps
www.indiandentalacademy.com
38. Shorp incising units
They should not contact during
mastication
Flat incisal guidance
Horizontal over lap
Contact only during protrusive incising
www.indiandentalacademy.com
39. Efficient in cutting and grinding
Decreased bucco-lingual width
Function as a group with simultaneous
harmoneus contacts
Over the crest of ridge for lever balance
Have a surface to receive and transmit
force of occlusion vertically
Plane of occlusion should be as parallel
as possible
www.indiandentalacademy.com
40. Contact on 2nd molars when incising
units contacts
Contact at the end of chewing cycle
when working units contacts
Smooth gliding contacts for lateral and
protrusive movements
www.indiandentalacademy.com
41. Smaller occlusal area– smaller crushing
force
Vertical force on inclined occlusal
surfaces
Vertical force on denture base with
resilient tissues
Vertical force lateral to ridge crest
Vertical force on inclined supporting
tissues
www.indiandentalacademy.com
43. Hundreds of years ago teeth were carved
from stone, wood, ivory and metal.
Human teeth
3 types
a) anatomic teeth of 33˚ or more
b)modified anatomic teeth between
3o˚and 0°
c)non anatomic or zero degree
www.indiandentalacademy.com
45. In 1913 Dr. Alfred Gysi of
Switzerland carved the
first anatomic porcelain
tooth.
Marketed by Dentist
supply company and were
called Trubyte.
They had transverse
ridges for tight inter
digitation
Pilkington and turner’s
30˚
Allow for small degree of
freedom in protrusive but
tight interlocking in
lateral excursions
www.indiandentalacademy.com
46. In 1927 Gysi also
introduced the
cross-bite teeth.
Maxillary buccal
cusp was almost
eliminated resulting
one prominent
lingual cusp that
occlude into lower
anatomic tooth
www.indiandentalacademy.com
47. In 1928 Victor
Sears introduced
channel teeth.
Maxillary occlusal
surfaces consists of
deep channel that
run mesio distally.
Lower posteriors
are half of width in
bucco lingually.
www.indiandentalacademy.com
48. Avery bros in 1930
introduced the
Scissor bite teeth.
Posterior occlusal
surfaces locked
antero posteriorly
and free in lateral
excursion
www.indiandentalacademy.com
49. In 1936 Mc
Grane marketed a
tooth which he called
the curved cusp
posterior tooth.
This design lock
antero posteriorly but
free in laterally in an
arc corresponding to
an orbitary radius
from vertical
rotational axis of
condyles
www.indiandentalacademy.com
50. In 1937 Max Pleasure
proposed to modify the
lower posterior teeth
occlusal surfaces to a
reverse curve by tilting
the tooth buccally.
Reverse curve in pre
molars , flat occlusal
surface on 1st
molars
and a monson curve on
2nd
molar for balance.
www.indiandentalacademy.com
51. John Vincent in
1942 introduced a
change in materials
by using metal
inserts in resin
posteriors.
Originally gold
solder wire and
later stain less
steel.
www.indiandentalacademy.com
52. Sosin in 1961
replaced maxillary
second bicuspid and
first & second molars
with cleat shaped
vitallium forms called
cross-blades.
Levin modified this
scheme by reducing
the size of the cross-
blade to the
maxillary lingual
cusp.
www.indiandentalacademy.com
53. HALL’S inverted
cusp teeth
In 1929 Hall was
the first to design
cuspless teeth he
called inverted cusp
tooth.
Tooth was flat with
concentric cone
shaped depressions
on occlusal surfaces
www.indiandentalacademy.com
54. Had a series of
transverse bucco-
lingual ridges
www.indiandentalacademy.com
55. In 1934 Nelson
described teeth he
called chopping
blocks, which were
flat occlusal
surfaces with
numerous ridges.
Ridges on
mandibular teeth
ran transversely
and on maxillary
they ran mesio
distally.
www.indiandentalacademy.com
56. In 1946 Hardy designed
a metal insert upper
and lower posterior
which he called
Vitallium occlusal.
Marketed by Austenal
Company and are still in
use
Produced in resin blocks
of 3 posterior teeth
A narrow vitallium
ribbon
www.indiandentalacademy.com
57. In 1951 Myerson Tooth
Corporation introduced
the first cross-linked
acrylic teeth in a flat
occlusal scheme called
the Shear cusp tooth.
Sears and myerson
proposed a
combination of
porcelain and acrylic
occlusal scheme.
www.indiandentalacademy.com
58. In 1952 Coe
Masticators designed
by Cook
2nd
premolars and 1st
molars were flat
stainless steel castings
with holes on the
occlusal surfaces
diagonally
These teeth occlude
with flat upper
porcelain teeth
www.indiandentalacademy.com
59. In 1957 Bader
introduced cutter bar
scheme by opposing
upper porcelain cusp
less teeth with a metal
cutting bar replacing 2nd
premolar, 1st
& 2nd
molar.
Similar to sears
channel tooth exept the
maxillary molars were
flat
www.indiandentalacademy.com
61. Adjustable articulators
Eccentric records
Harmonious occlusion is lost when bases
are not stable
Bases need frequent refitting
Presence of cusps generates more
horizontal forces
www.indiandentalacademy.com
62. occlude only in 2-dimension
Less shearing efficiency
Bilateral and protrusive balance is not
possible
Esthetically poor.
www.indiandentalacademy.com
64. “ The bilateral , simultaneous , anterior and
posterior occlusal contact of teeth in centric
and eccentric positions ”
Cusp form posterior teeth.
Purpose of B O .
Balance in natural teeth.
www.indiandentalacademy.com
65. Wider , larger the ridge and closer the
teeth to the ridge.
Wider the ridge and narrower the teeth
bucco lingually
More lingual the teeth in relation to
ridge crest
More centered the force of occlusion
antero posteriorly.
www.indiandentalacademy.com
67. Tooth size and position in relation to
ridge size and shape.
Denture base coverage
Occlusal balance at retruded contact
position
Right and left eccentric occlusal balance
www.indiandentalacademy.com
70. Inclination of condylar guidance
The prominence of the compensating
curve
The inclination of the plane of
occlusion–orientation of occlusal plane
The inclination of incisal guidance
The heights of the cusps – inclination of
cusps.
www.indiandentalacademy.com
71. CONDYLOR INCLINATION
(GUIDANCE )
Determined on the
patient by a
protrusive record
and set on the
instrument.
Under the influence
of anterior slope of
glenoid fossa.
www.indiandentalacademy.com
72. SAGITTAL
CONDYLOR
GUIDANCE ANGLE
Average path
taken by the
condyle during a
farward
movement from
centric relation
position when
viewed in a
sagittal plane.www.indiandentalacademy.com
73. : Is the influence of the
contacting surfaces of the
mandibular and maxillary
anterior teeth on
mandibular movement.
It can be set by dentist in
accordance with esthetics
and phonetics.
If the incisal guidance is
steep it calls for steep
cusps, steep occlusal
plane or a steep
compensating curve to
effect an occlusal balance
Incisal guidance should be
as flat as possible.
www.indiandentalacademy.com
74. SIGA
Sagittal incisal
guidance angle
is formed by
vertical overlap
between teeth.
It is only
dependent on
amount of
horizontal
overlap.
www.indiandentalacademy.com
75. ORIENTATION OF OCCLUSAL
PLANE
Is established in
the anterior by
height of the lower
cuspid and in the
posterior by the
height of the
retromolar pad.
Occlusal plane
should be similar to
the natural teeth.
www.indiandentalacademy.com
76. COMPENSATING CURVE
compensating curve is
one of the most important
factors in establishing a
balanced occlusion. The
compensating curves
eliminate Christensen’s
phenomenon to achieve
balance.
It is determined by the
inclination of the posterior
teeth and their vertical
relationship to the
occlusal plane. A steep
condylar path requires a
steep compensating
curve for occlusal balance.
www.indiandentalacademy.com
77. INCLINATION OF THE CUSPS
OF THE TEETH
Refers to the angle
between the total
occlusal surface of
tooth and the
inclination of the cusp
in relation to that
surface.
33° tooth inclination.
The basic inclination of
cusps can be made
steeper
www.indiandentalacademy.com
78. FACTORS OF BALANCED OCCLUSION
RELATED TO A BALANCE BEAM
If the incisal guidance is made steeper
the beam is out of balance.
www.indiandentalacademy.com
79. Equation for determining
degree of inclination
Cuspal inclination=incisal
inclination+1/2(condylar inclination-
incisal inclination)
For e.g. c.g is 40°and i.g is 30°
Cuspal inclination=30˚+1/2(40˚-30˚)
=35°
www.indiandentalacademy.com
80. Factors of lateral balance
The inclination of the condylar path on the
balancing side.
The inclination of the incisal guidance and
cuspid lift.
The inclination of the plane of occlusion on the
balancing side and working side.
The compensating curve on the balancing side
and working side.
The buccal cusp heights or inclinations on the
balancing side.
The lingual cusp heights or inclination on the
working side.
The Bennett side shift on the working side.
www.indiandentalacademy.com
82. LINGUALIZED OCCLUSION
First described by S.
Howard Payne, DDS, in
1941,
This form of denture
occlusion articulates the
maxillary lingual cusps
with the mandibular
occlusal surfaces in
centric, working and
nonworking mandibular
positions. The term is
attributed to Earl Pound.
Maxillary Lingual Cusps
acts as the centric
holding cusps
www.indiandentalacademy.com
83. LINGUALIZED OCCLUSION
• No contact of the
maxillary buccal
cusps with
mandibular buccal
or lingual cusps.
Anatomic teeth are
used in maxillary
arch.
Semi Anatomic or
non anatomic teeth
can be selected for
mandibular arch.
www.indiandentalacademy.com
84. MOLDS FOR LINGUALISED OCCLUSION
Maxillary teeth
are anatomic
Mandibular
occlusal forms
require some
minor reshaping
www.indiandentalacademy.com
86. RATIONALE FOR LINGUALISED
OCCLUSION
Maximum intercuspation must occur at the
centric jaw relation position
An absence of deflective occlusal contacts
or tooth interferences must be observed
between opposing teeth
The arrangement and articulation of
artificial tooth forms must provide enough
cusp height to permit selective occlusal
reshaping to achieve an absence of
interferences
A natural and pleasing appearance must
be achievable with the tooth arrangement
www.indiandentalacademy.com
87. Factors in the tooth molds
for lingualized articulation
The mandibular arch offers the most
recognizable anatomic landmarks used
for arranging artificial teeth.
1. The number of teeth selected
2. Anterior and posterior reference
points.
3. Bucco-lingual positioning of the teeth.
4. Antero-posterior compensating curve.
5. Medio-lateral compensating curve.
www.indiandentalacademy.com
91. Flat planes in all directions
Balance was unnecessary and
undesirable.
www.indiandentalacademy.com
92. Eliminates antero-posterior and medio-
lateral inclines of teeth.
Horizontal condylar guidance set at 0.
Lateral condylar guidance set at 0.
Bucco lingual width of teeth is reduced.
No of teeth is reduced.
www.indiandentalacademy.com
94. In 1966 J. F .FRUSH described
occlusion in 3 geometric terms .
One dimensional-linear occlusion
Two dimensional – flat plane
Three dimensional – cuspid.
This scheme increases stabllity.
www.indiandentalacademy.com
95. • Linear ( non interceptive ) occlusion
consists of following requirements
1 . Zero degree teeth are opposed by
bladed teeth
2 . Mandibular teeth are set to a flat
occlusal plane
3 . There is no anterior tooth
interference to protrusive or lateral
movement.
www.indiandentalacademy.com
96. Mandibular
prosthesis
stability can be
analyzed with
anatomic teeth ,
zero degree ,and
linear teeth .
ANATOMIC
TEETH
www.indiandentalacademy.com
97. ZERO DEGREE
TEETH WITH
MONOPLANE
OCCLUSAL
SCHEME.
www.indiandentalacademy.com
100. Prosthodontic treatment for edentulous patients—
Boucher’s 9th
edi.
Essentials of complete denture prosthodontics— Sheldon
winklers 2nd
edi
Text book of complete dentures– Rahn & Heartwell 5th
edi
Complete denture occlusion-D C N A .2004 ;641-665
Maximising mandibular prosthesis stability utilising linear
occlusion, occlusal plane selection and centric recording
( JPD 2004;13;55-61)
A randamised clinical trial comparing anatomic, lingualised
,and zero-degree posterior occlusal forms for complete
dentures.( JPD 2007;97;292-8)
History of articulators;a critical history of articulators
based on geometric theories of mandibular
movement;part 1(JP,JUNE 2002 ;134-146 )
www.indiandentalacademy.com