Department of Prosthodontics Balanced occlusion Various theories and Hanau's Quint

1. DEPARTMENT OF PROSTHODONTICS
By
Reema Talat Ayesha
Final year
R.R.D.C

2. • Definition
• Types of Balanced Occlusion
-Unilateral
-Bilateral
-Protrusive
-Lateral
• Concepts of Balanced Occlusion
-Gysi’s concept
-French’s concept
-Sears concept
-Pleasure’s concept
-Hanau’s Quint
-Trapozzano’s concept of occlusion
-Boucher’s concept
-Lotts concept
• Factors influencing Balanced Occlusion

3. DEFINITION
‘The simultaneous contacting of the maxillary and
mandibular teeth on the right and left side and in
the posterior and anterior occlusal areas in centric
and eccentric positions, developed to lessen or
limit tipping or rotating of the denture bases in
relation to the supporting structures”-GPT

4. Types of Balanced Occlusion
Unilateral Balanced Occlusion
This is a type of occlusion seen on occlusal surfaces
of teeth on one side when they occlude
simulatenously with a smooth , uninterrupted
glide. This is not followed during complete denture
preparation. It is more pertained to fixed partial
dentures.
 Bilateral Balanced Occlusion
This is a type of occlusion that is seen when a
simultaneous contact occurs on both sides in
centric and eccentric positions. Bilateral balanced
occlusion helps to distribute the occlusal load
evenly across the arch and therefore helps to
improve stability of the denture during centric,
eccentric or parafunctional movements.

5. Protrusive balanced Occlusion
This type of balanced occlusion is present when
mandible moves in a forward direction and
the occlusal contacts are smooth and
simultaneous anteriorly and posteriorly.There
should be atleast three points of contact in
the occlusal plane.Two located posteriorly and
one anteriorly.Absent in natural dentition.
Posterior contact during protrusion to
maintain balance

6. Lateral Balanced Occlusion
In lateral balance there will be a minimal
simultaneous three point contact present during
lateral movement of mandible.This is absent in
natural dentition.Teeth should be arranged such
that there is simultaneous tooth contact in
balancing side and working side.
Canine guided disocclusion.This
relationship is seen in natural
dentition
Anterio and posterior tooth
contact during laterotrusion
seen on working side.

7. Mechanics of balanced occlusion
In natural teeth when the mandible is
protuded so that the incisal edges of
the upper & the lower teeth contact,
there is a gap between the upper &
lower posterior teeth, this is termed as
“Christensen’s phenomenon”.
But this occlusion could cause tipping
of the denture in the posterior
region. Thus simultaneous anterior &
posterior contacts are required when
mandible is protruded.

8. Concepts proposed-
• Gysi’s concept
He proposed the first concept
towards balanced occlusion in
1914.He suggested arranging 33
degree anatomic teeth could be
used under various movements of
the articulator to enhance the
stability of the denture.

9. • French’s concept
He proposed lowering the lower occlusal
plane to increase the stability of the
dentures along with balanced occlusion.he
arranged upper first premolars with 5º
inclination,upper second premolars with
10º inclination and uppe r molars with 15º
inclination.He used modified French teeth
to obtain balanced occlusion.
• Sears’s Concept
He proposed balanced occlusion for non
anatomical teeth using posterior balancing
ramps or an occlusal plane which curves
anteroposteriorly and laterally.

10. • Pleasure’s concept
Pleasure introduced a pleasure curve or
the posterior lateral curve to align and
arrange posterior teeth in order to
increase the stability of the denture.
• Frush’s concept
He advised arranging teeth in a one
dimensional contact relationship,which
should be reshaped during try in to
obtain balanced occlusion.

11. • Hanau’s Quint
Rudolph L.Hanau proposed nine factors that govern the
articulation of artificial teeth.They are
-Horizontal condylar guidance
-Compensating Curve
-Protrusive Incisal Guidance
-Plane of orientation
-Buccolingual inclination of tooth axis
-Saggital condylar pathway
-Saggital Incisal Guidance
-Tooth Alignment
-Relative Cusp Height
“LAWS OF BALANCED ARTICULATION”

12. Hanau later condensed these nine
factors and formulated five
factors which are commonly
known as Hanau’s Quint:
-Condylar Guidance
-Incisal Guidance
-Compensating curves
-Relative Cusp Height
-Plane of Orientation of
occlusal plane

13. A). Incisal guidance
B). Condylar guidance
C). Cuspal angulation
D).plane of occlusion
E). Compensating curve.

14. • Trapozzano’s Concept of Occlusion
HE reviewed and simplified Hanau’s
Quint and proposed his Triad Of
Occlusion.He said that plane of
occlusion could be shifted to
favour weak ridges,hence its
location is not constant and is
variable within the inter arch
distance.
-Condylar Guidance
-Incisal Guidance
-Relative Cusp Height

15. • Boucher’s Concept
Boucher proposed the following three
factors for balanced occlusion.
-Orientation of the occlusal
plane,the incisal guidance
and the condylar guidance.
-The angulation of the cusp is
more important than the height of
the cusp.
-The compensating curve
enables one to increase the height
of the cusp without changing the
form of teeth

16. • Lott’s Concept
-The greater the angle of the condylar path,the
greater is the posterior separation during
protrusion.
-The greater the angle of the overbite,the
greater is the separation in the anterior and
posterior regions irrespective of the angle of
the condylar path.
-The greater the separation of the posterior
teeth the greater or higher must be the
compensating curve.
-Posterior separation beyond the balancing
abiltiy of the compensating curve can be
balanced by the introduction of the plane of
orientation.
-The greater the separation of the teeth, the
greater must be the height of the cusps of
posterior teeth.

18. • Levin’s Concept
He named the four factors of occlusion as
the QUAD
-The condylar guidance is fixed and is
recorded from the patient.
-The incisal guidance is usually obtained
from patients esthetic and phonetic
requirements
-The compensating curve is the most
important factor in obtaining occlusal
balance.
- Cusp teeth have the inclines necessary
for balanced occlusion but nearly always
used with a compensating curve.

20. Factors influencing balanced occlusion
Thielemann’s formula
• Balanced Occlusion= K . I
• OP .C . OK
• Where,
• K CONDYLAR INCLINATION,
• I INCISAL INCLINATION,
• C CUSPAL HEIGHT,
• OP INCLINATION OF PLANE OF
ORIENTATION,
• OK PROMINANCE OF
COMPENSATING CURVE.

21. 1. CONDYLAR GUIDANCE
“Mandibular guidance generated
by the condyle and articular disc
traversing the contour of the
glenoid fossae”
This is the only factor which can be
recorded from patient.It is
registered using prostrusive
registration and transferred to the
articulator as the condylar
guidance.This factor of Balanced
occlusion cannot be modified.

22. a).Horizontal condylar guidance-guides
the forward movement for
protrusive balance.
b).Lateral condylar guidance-guides
the sideward or lateral movement of
the mandible.
Posterior slope of the articular
eminence represented by the
condylar tract of articulator

23. 2. INCISAL GUIDANCE
“The influence of the contacting surfaces of
the mandibular and maxillary anterior
teeth on mandibular movements’
It is determined by the dentist and
customised for the patient during
anterior try in. It acts as a controlling
path for the movements of the casts in
an articulator.Its should be set
according to the desired overjet and
overbite planned for the patient.If
overjet is increased,the inclination of the
incisal guidance is decreased.The incisal
guidance has more influence on
posterior teeth than condylar guidance.

25. 3. PLANE OF OCCLUSION OR OCCLUSAL
PLANE
“
An imaginary surface which is related
anatomically to the cranium and which
theorotically touches the incisal edges of
the incisors and tips of occluding
surfaces of the posterior teeth.It is not a
plane in the true sense of word but
represents the mean curvature of the
surface “
It is established anteriorly by the height of
the lower canine,which nearly coincides
with the commisure of the mouth and
posteriorly by the height of the retro
molar pad.It is usually parallel to
Camper’s line.
The plane of occlusion can be altered
to a maximum of 10o

26. 4. COMPENSATING CURVES
“The anteroposterior and lateral
curvatures in the allignment of the
occluding surfaces and incisal
edges of artificial teeth which are
used to develop balanced
occlusion.”
2 types of curves:
-Anteroposterior curves
-Lateral curves

27. Curve of Spee
“Anatomic curvature of the occlusal
alignment of teeth beginning at the tip of
lower canine and following buccal cusps of
natural premolars and molars,continuing to
the anterior border of ramus”
It is seen in the natural dentition and should be
reproduced in a CD. The significance of the curve
is that, when the patient moves his mandible
forward, the posterior teeth set on this curve will
continue to remain in contact.
Posterior teeth separation
when the curve of spee not
incorporated
Incorporating the curve spee
will provide posterior tooth
contact during protrusion

28. Monson’s Curve
“The curve of occlusion in
which each cusp and incisal
edges touches or conforms to
a segment of a sphere of 8
inches in diameter with its
center in the region of
Glabella.”
Only if teeth are set following
Monsons curve will there be
lateral balance of occlusion.
runs across the palatal & buccal cusps
of maxillary molars.

29. • Wilson’s Curve
“A curve of occlusion which
is convex upwards”
This curve is followed when
first premolars are
arranged. The premolars
are arranged according to
this curve so that they do
not produce any
interference to lateral
movements.

30. Lateral view with 2nd PM
& 1st molar follow the
reverse curve
Pleasure Curve/Reverse Curve
“A curve of occlusion which in
transverse cross section conforms to
a line which is convex upward except
for last molars”
This curve runs from palatal cusp of
the first premolar to the distobucaal
cusp of second molar,The second
molar gives occlusal balance and the
second premolar gives lever balance.
Reverse curve is
used in the
bicuspid area for
lever balance

31. 5. Cuspal Angulation
“The angle made by the average slope of
a cusp with the cusp plane measured
mesiodistally and buccolingually”
The cusps on the teeth or the
inclination of the cuspless teeth are
important factors that modify the
effect of plane of occlusion and the
compensating curves. The mesiodistal
cusps lock the occlusion, such that
the repositioning of teeth does not
occur due to settling of the base. To
prevent the locking of occlusion the
mesiodistal cusps are reduced during
occlusal reshaping.