ByBy Bhushan Chavan Bhushan Chavan
Occlusion in Complete Denture
Introduction
What is Occlusion? Occlusion is a relationship between the occlusal surfaces of maxillary and mandibular teeth when they are in contact.
Ideal Requirements Of Complete Denture Occlusion
- Stability of denture and occlusion in centric and eccentric relation
- Balanced occlusal contact in all eccentric movements.
- Reduced cuspal height to control horizontal forces.
- Functional lever balance sholud be obtained by vertical tooth to ridge crest relationship
- Cutting,penetrating and shearing efficiency of the occlusal surface
- Incisal clearance during posterior functions like chewing
- Minimal area of contact to reduce pressure while crushing food
Units In Complete Denture Occlusion INCISAL UNITINCISAL UNIT : Includes four incisors
WORKING UNITWORKING UNIT : Includes Canine and Posterior teeth of the sides toward which mandible moves
BALANCING UNITBALANCING UNIT : Includes canine and posterior teeth opposite to the working side.
Ideal Requirements Of Occlusal Units
INCISAL UNITINCISAL UNIT 1)Sharp incisal edges 2)No contact during mastication 3)Shallow incisal guidance 4)Increased horizontal overlap WORKING UNITWORKING UNIT 1)Cusp for grinding and cutting efficiency 2)Smaller buccolinual width 3)Plane of occlusion parallel to the plane of ridge 4)Occlusal load directed to the anteroposterior centre of denture BALANCING UNITBALANCING UNIT 1)Second molar Should be in contact during protrusive action 2)They should have contact along with the working side at the
end of chewing cycle 3)Smooth guiding contacts for lateral and protrusive movements
CONCEPTS OF OCCLUSIONBALANCED OCCLUSION
NON-BALANCED OCCLUSION
LINGUALIZED OCCLUSION
BALANCED OCCLUSIONDEFINITION:- The simultaneous contacting of the
maxillary and mandibular teeth on the right and left 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.
It is associated cusp form posterior teeth
BALANCED OCCLUSION(contd.)
REQUIREMENTS:-All the teeth of working side should glide evenly
against opposing teeth No single tooth should produce any interference or
any disocclusionThere should be contacts in balancing side but they
should not interfere with smooth gliding movements of working side
There should be simultaneous contact during protrusion
BALANCED OCCLUSION(contd.)
GENERAL CONSIDERATIONS:-Ideal balance can be achieved in cases with wide
and large ridges and in complete dentures with teeth arranged close to the ridge
Complete dentures that have teeth arranged away from the ridge and those that rest on narrow and short ridges will have poor balanced occlusion
Teeth that have narrow buccolingual width provide ideal balanced occlusion
Ideal balance can be achieved by arranging the teeth slightly on lingual side of ridge
BALANCED OCCLUSION(contd.)TYPES:-
- UNILATERAL BALNCED OCCLUSION
- BILATERAL BALANCED OCCLUSION
- PROTRUSIVE BALANCED OCCLUSION
- LATERAL BALANCED OCCLUSION
BALANCED OCCLUSION(contd.)UNILATERAL BALANCED OCCLUSIONUNILATERAL BALANCED OCCLUSIONOcclusal surfaces of teeth on one side when
they occlude simultaneously with smooth uninterrupted glide
Related to FPD
BILATERAL BALANCED OCCLUSIONBILATERAL BALANCED OCCLUSIONSimultaneous contact occurs on both sides in
centric and eccentric relations
BALANCED OCCLUSION(contd.)PROTRUSIVE BALANCED OCCLUSIONPROTRUSIVE BALANCED OCCLUSIONWhen mandible moves in forward direction
and the occlusal contacts are smooth and simultaneous anteriorly and posteriorly.
LATERAL BALANCED OCCLUSIONLATERAL BALANCED OCCLUSIONMinimal simultaneous three point contact
present during lateral movement of mandible
BALANCED OCCLUSION(contd.)
FACTORS INFLUENCING BALANCED OCCLUSIONInclination of condylar path or condylar guidance
Incisal guidance
Orientation of plane of occlusion or occlusal plane
Cuspal angulation
Compensating curves
NON-BALANCED OCCLUSIONDEFINITION:-It is an arrangement of teeth with form or
purpose It is used to set non-anatomic teeth in
occlusionIt includes following conceptsSpherical theoryOrganic or Organised occlusionOcclusal balancing ramps for protrusive
balanceTransographics
NON-BALANCED OCCLUSION (contd.)Spherical theorySpherical theory According to this theory,anteroposterior and mesiodistal inclines
of artificial teeth should be arranged in harmony with spherical surface.
Organic occlusionOrganic occlusion Arrangement of teeth should relate the occlusal elements of
teeth so that teeth will be in harmony with muscles and joints in function
It has 3 phases of mutually interdependent protecttion - Posterior teeth should protect anterior teeth in centric occlusal
position - The maxillary incisors should have vertical overlap sufficient to
provide the separation of the posterior teeth when incisors are in end to end contact
- In lateral mandibular positions outside the masticatory cyclic movements the cuspid should prevent the contact of all other teeth
NON-BALANCED OCCLUSION (contd.)
General considerations:-Opposing teeth should not contact when
jaws are in eccentric relation since it may give destabilizing forces to the basal seat area
Tooth contact should occur only when the mandible is in centric relation to maxilla
The patient should be encouraged to repeat mandibular movements till there is no discomfort in centric relation
LINGUALIZED OCCLUSIONIt involves the use of large palatal cusps
against wide lower central fossa
Maxillary palatal cusps are main functional occlusal elements
Characteristics BALANCED NON-BALANCED LINGUALIZED
OCCLUSION OCCLUSION OCCLUSION
1.Better + - +
Esthetics
2.Ease of + - +
penetration
3.Denture
stability during + - +
parafunctional
movements
4.Simple techinique - + +
Characteristics BALANCED NON-BALANCED LINGUALIZED
OCCLUSION OCCLUSION OCCLUSION
5.Decreased lateral - + +
forces
6.Ease of adjustment - + +
7.Class II and III - + +
jaw relations
8.Good stability, - + +
forces centralized
& neutralized