Introduction
OCCLUSION: occlude means to (CLOSE)
-The static relationship between the incising or masticating
surface of the maxillary or mandibular teeth or tooth
analogues (GPT 8)
-It is important to plan occlusal scheme prior to selection and
arrangement of artificial teeth
-Occlusal scheme is defined as the form and the arrangement of
the occlusal contacts in natural and artificial dentition.
-The choice of an occlusal scheme will determine the pattern of
occlusal contacts between opposing teeth during centric relation
and functional movement of the mandible. With dentures, the
quantity and the intensity of these contacts determine the
amount and the direction of the forces that are transmitted
through the bases of the denture to the residual ridges. That is
why the occlusal scheme is an important factor in the design of
complete dentures.
Requirements of complete denture occlusion:
Cutting,Penetrating and shearing efficiency of occlusal surface
Minimum occlusal contact areas
Reduced posterior cusp height to control horizontal forces
Reduced buccolingual width of posterior teeth to decrease
forces
transmitted to residual ridge
Stability of occlusion at centric relation position and in area
forward
and lateral to it
Stability of occlusion in centric and eccentric relations
Balanced occlusal contacts
Types of Denture Occlusal Schemes
1) Balanced Occlusion
-The bilateral, simultaneous,anterior and posterior
occlusal contact of teeth in centric and eccentric
positions" (GPT8)
- It is not seen in the natural teeth, if it occur in natural teeth
it is considered as
premature contact on non working side and considered as
pathologic
- It enhances the stability of denture
- Balance in complete denture is unique and man made
-
Types of balanced occlusion:
A. Unilateral lever balance
B. Unilateral occlusal balance
C. Bilateral occlusal balance
D. Protrusive occlusal
A-Unilateral lever balance
This is present when there is equilibrium of the base on its supporting
structures when a bolus of food is interposed between the teeth on
one side and a space exist between the teeth on the opposite side.
B- Bilateral occlusal balance
• This is present when there is equilibrium on both sides of denture
due to simultaneous
contact of teeth in centric and eccentric occlusion
• It requires a minimum of a three contacts for establishing a plane of
equilibrium, the
more the contacts the more assured equilibrium
C-Unilateral occlusal balance
This is present when the occlusal surfaces of teeth on
one side articulate simultaneously as a group with a
smooth uninterrupted glide
D-Protrusive occlusal balance
This is present when the mandible moves essentially forward and the
occlusal
contacts are smooth and simultaneous in the posterior both on right
and left
sides and on anterior teeth
It is slightly different from bilateral balance in that it it requires a
minimum of
three contacts (one on each side posteriorly and one anteriorly)
Factors affecting balanced occlusion
1.Condylar Guidance
2.Incisal Guidance
3.Plane of Occlusion
4.Compensating Curves
5.Cuspal Inclination
Advantage:-
Bilateral simultaneous contact help to seat the denture in a stable
position during
mastication,swallowing and maintain retention
• Denture bases are stable even during bruxing activity
• Cross arch balance
Disadvantage:-
• It is difficult to achieve in mouths where an increased vertical incisor
overlap is present-class Il Cases
• It may tend to encourage lateral and protrusive grinding habits
• A semi adjustable or fully adjustable articulator required
2) Monoplane Occlusion
"An occlusal arrangement where in the posterior teeth
have masticatory surfaces that lack any cuspal
height" (GPT8)
- Occlusal arrangement using non anatomic teeth
- Anterior teeth are arranged with an overjet of 2mm and no
overbite
- Monoplane occlusion can be balanced by placing balanced ramps
distal to second molar, it will improves horizontal stability of
denture.
Advantage:-
They are more adaptable to unusual jaw relation such as class I
and class Ill relations
Easy to arrange teeth and less time consuming
They eliminate horizontal forces,more damaging than vertical
forces
They accommodate better to the negative change in the ridge
height that occur with aging
Simple non adjustable articulator is sufficient
Disadvantage:
No vertical Component to aid in shearing during mastication
Lack of positive intercupation
Poor Appearance
3) Lingualized Occlusion
"This form of denture occlusion articulates the maxillary lingual
cusps with the mandibular occlusal surfaces in centric working and
non working mandibular positions" first described by S Howard
Payne in 1941 (GPT8)
Lingualized occlusion can be a type of bilaterally balanced occlusal
cheme
Anatomic tooth are used in maxilla opposing a flat cusped o
shallow cusped mandibular tooth
Forces directed towards lingual side
Maxillary lingual cusp articulates with mandibular central fossae
Advantage:-
Cusp form is more natural in appearance compared to non
anatomic forms
Good penetration of bolus is possible this may reduce the lateral
chewing component
Both anatomic and non anatomic tooth forms are retained
Simple technique
Can be used in Class IL Class IIIV And cross bite situations
Disadvantage:-
Wearing of maxillary lingual cusp or mandibular fossa
More challenging teeth arrangement than monoplane occlusion
