Developments in the Occlusal patterns of artificial Teeth / orthodontic continuing education

THE DEVELOPMENTS IN THE
OCCLUSAL PATTERNS OF
ARTIFICIAL TEETH
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

CONTENTS
 INTRODUCTION.
 SPECIFICATIONS OF POSTEROIR
ARTIFICIAL TEETH- BY SEARS AND
PLEASURE.
 GROUPS OF ARTIFICIAL TEETH.
 HISTORYOF DEVELOPMENT.
 EXPERIMENTAL STUDIES.
 CONCLUSION.

INTRODUCTION
 The occlusal surfaces are the primary
concern in selecting the form of the
posterior teeth.
 According to Gysi “ Artificial teeth can
be properly formed only by the
application of the knowledge of the
conditions under which they must
function .”

SPECIFICATIONS FOR POSTERIOR
TEETH FORM-SEARS AND PLEASURE
1. No interferring projections between centric
and eccentric tooth positions to restrict
mandibular movements.
2. It is possible to set them in cross-bite
relationship if necessary.
3. Working occlusal area should be lingually
placed from the ridge crest.
4. It should provide bilateral balance without
sacrificing ideal angle of working occlusal
surface

SPECIFICATIONS(CONT)
5. Bulk of teeth should be sufficient to make
satisfactory contact with tongue and fill
buccal vestibule.
6. All working surfaces should be at right
angles to the direction of closing force.
7. Teeth may be altered by grinding without
losing their mechanical (or) esthetic
advantage
8. Occusal form should permit compensation
for change in ridge relation.

SPECIFICATIONS(CONT)
9. No wells or hollows in which food can
pack.
10.They must present degree of cutting
efficiency required to cut fibrous
foods and thus diminishing trauma to
tissues.
11. Relation of opposing occlusal
surfaces must not interfere with
arrangement of anterior teeth.

GROUPS OF ARTIFICIAL TEETH
 Based on occlusal form of posterior
teeth they are Grouped into 2 types
 ANTOMIC AND NON-ANTOMIC TEETH

ANATOMIC TEETH
1. Simulate natural
tooth form.
2. Have cuspal height
with varying cuspal
inclines.
3. Three dimensional
intercuspation
4. More efficient in
mastication.
5. Increased
horizontal forceswww.indiandentalacademy.com

NON-ANTOMIC TEETH
1. Doesn’t simulate
natural teeth form.
2. No cuspal height
with flat cuspal
form.
3. Two dimensional
Intercupation.
4. Not efficient in
mastication.
5. Decreased
horizontal forces but
increased vertical
forces

18th
century
 In olden days artificial teeth were
carved from stone, wood, ivory,
metal and even human teeth used to
replace lost tooth.
 As these are not esthetic,long lasting
and dosen’t perform masticatory
function well, search for an ideal
artifical tooth has began.

HISTORY OF DEVELOPMENT
 ANATOMIC TEETH
1. Gysi- 1913-1928
2. Sear’s- 1928
3. Avery- 1930
4. French’s- 1935
5. McGrane’s- 1936
 NON-ANTOMIC
TEETH
1. Hall- 1929
2. Myerson- 1929
3. Nelson- 1934
4. Swenson- 1939
5. Hardy- 1946

TRUBYTE TEETH-Dr.Alfred Gysi
 FEATURES:
Teeth had cuspal
angle of 33
degrees,
Transverse ridges
present and were
intended for tight
interdigitation

TRUBYTE TEETH-1913
 PRINCIPAL:
Designed to function harmoniously
with incisal and condylar guidances
simulating natural tooth.
 ADVATAGES:
1.Simulated natural tooth form.
 DISADVATAGES:
1.Dislodgement of denture in severly
resorbed ridges.

CROSS-BITE TEETH(GYSI)-1928
 Principle:
“mortar and pestle”
Action by Brenner and
payne.
-Features: Buccal cusps
are grinded.
 Disadvantage:
Shifting of denture
bases .

CHANNEL TEETH-SEAR’S(1928)
 FEATURES:
Channels run
mesio-distally, with
working occlusal
surface 1mm to
1.5mm width. The
buccal and lingual
plane fall away
from central
horizontal fossa.

SEAR’S CHANNEL TEETH
 PRINCIPLE:
 For efficient cutting and to prevent denture
base instability channels were created on
occlusal surfaces running mesio-distally
 ADVANTAGES:
Free movement in antero-posterior
direction.
 DISADVATAGES:
1.Lock and interference in lateral
excursions.
2.No food table.

AVERY BROTHER’S-SCISSOR-BITE
TEETH(1930)
 FEATURES:
 No cuspal inclines
bucco-lingually.
 Definite interlock
antero-posteriorly
to prmote shearing
action

 PRINCIPLE:
 To promote shearing action buccal and lingual inclines
were eliminated, which is an outstanding feature of
AVERY brothers teeth.
 ADVATAGE:
 Shearing of food in lateral excursions
 DISADVATAGE:
 Food accumulates in buccal vestibule
 When food floats over to the balancing side it is
subjected to rubbing action not shearing action.

FRENCH’s posterior teeth(1935)
 FEATURES:
 Eliminated buccal
cups.
 No antero-posterior
cuspal inclines.
 Central groove running
in mesio-dista sirection
but with very shallow
bucco-lingul inclines to
reduce lateral thrust

 PRINCIPLE:
 Design placed the occlusal forces
lingually.
 ADVANTAGE:
1.Greater denture stability.
 DISADVANTAGE:
1.Did not provide for balancing
contacts in either lateral or
prorusive excursions.

McGRANE’S CUVED CUSP(1936)
 FEATURES:
 Antero-posterior
lock without buccal
and lingual inclines

 PRINCIPLE:
Curved cusp teeth are designed to lock antero-
posteriorly and free laterally in an arc corresponding
to an arbitary radius from each vertical rotational axis
of the right and left condyles.
 ADVATAGES:
1.NO TRAUMA TO THE TISSUES ON WORKING SIDE.
2.Shear food in harmonius with lateral condylar
guidance.
 DIADVANTAGES:
1.NO METHOD FOR ADJUSTMENT IN CASES WHERE
INTERFERENCES OCCURS.
2.No attempt made to get balanced occlusion.

HALL-INVERTED CUSP(1929)
 FEATURES:
 No cuspal
inclinations, flat
occlusal
surface,cutting
blades
incorporated in
occlusal carvings,
sluiceways are
included.

INVERTED CUSP TEETH
 PRINCIPLE:
 Function by simulating the action of
machine used to design cusps.
 ADVANTAGE:
1.Decreased horizontal forces on teeth.
 DISADVANTAGES:
1.Centrifugal force which clears the cups of
debris is not present in mouth and lower
teeth tend to retain teeth.

NELSON- CHOPPING BLOCK-(1934)
 FEATURES:
 Flat occlusal surfaces
with numerous ridges.
 Ridges on mandibular
teeth run transeversly
and in maxilla they
rum mesio-distally.
 ADVANTAGES:
 Ridges run
perpendicular to one
another in contact an
efficient shredding and
cutting action was
claimed.

SWENSON-NONLOCK-(1939)
 FEATURES:
 These are essentially
flat teeth with
sluiceways for
shredding and allowing
food to clear the
occlusal table.
 ADVATAGES:
 They provided
balancing contacts.

HARDY’S-VO (1946)
 Vitallium occlusal (VO)
metal insert placed in
upper and lower teeth
 A narrow zigzag of
vitallium ribbon was
embeded on the
occlusal surface and
ran mesio-distally
establishing a
narrow,flat, convoluted
metal surface that was
raised slightly above
encasing the resin

HARDY’S-VO- TEETH
 ADVATAGES:
1.Better chewing
efficiency.
 DISADVANTAGE:
1.Tongue irritation due to
metal insert.
 MODIFIED HARDY’
TEETH:
 Raising the plastic which
is molded around the
insert so it is high
enough on lingual
surface to prevent
tongue making contact.

EXPERIMENTAL STUDIES TO
EVALUATE CHEWING EFFICIENCY
OF DIFFERENT ARTIFICIAL TEETH
 THOMPSON- In 1937 tested 33 degree cusp
teeth,20 degree teeth, Hall’s teeth, and
Sear’s channel teeth.
He found Sear’s channel teeth were least
efficient .
 SOBOLICK-In 1938 tested on duplicate
dentures with different occlusal forms for
each individual and ranked their effeciency
in following order,Halls inverted cusp,true-
kusp,french’s and lastly tru-byte teeth.

OTHER POSTERIOR TEETH WITH
DIFFERENT OCCLUSAL FORMS
 MYERSON; SHER-CUSP- 1951
 COOK ; COOKS METAL- 1952
 DEVAN ; NEUTROCENTRIC- 1954
 BRADER ; CUTTER BAR - 1957
 FRUSH ; LINEAR OCCLUSAL- 1967

CONCLUSION
 As various posterior teeth different occlusal
forms has evolved, It is the clinician
responsibility to choose suitable teeth with
occlusal form for a particular patient
keeping following in mind
 1. Health and preservation of supporting
tissues.
2. Denture stability.
3. Forces directed to the ridge.
4. Masticatory efficiency.
5. Esthetics and phonetics.

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Developments in the Occlusal patterns of artificial Teeth / orthodontic continuing education

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