Occulsal Morphology Determinants

8/10/2019 Occulsal Morphology Determinants

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INTRODUCTION TO OCCLUSION

CUSP HEIGHT DETERMINANTS


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CUSP HEIGHT


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VERTICAL DETERMINANTS

ANGLE OF EMINENTIA

GRADUAL EMINENTIASLOPE REQUIRES SHORTCUSPS

STEEP EMINENTIA SLOPEPERMITS LONGER CUSPS


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VERTICAL DETERMINATS

VERTICAL OVERLAP (OVERBITE)

DEEP ANTERIOR OVERBITEPERMITS LONGER CUSPS

MINIMUM ANTERIOR OVERBITEREQUIRES SHORTER CUSPS


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VERTICAL DETERMINANTS HORIZONTAL

OVERLAP

(OVERJET) PRONOUNCED ANTERIOR

OVERJET REQUIRES SHORTERCUSPS

MINIMUM ANTERIOR OVERJET

PERMITS LONGER CUSPS


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VERTICAL DETERMINANTS

IMMEDIATE SIDE-SHIFT

EXCESSIVE IMMEDIATE SIDE-SHIFT REQUIRES SHORT CUSPS

GRADUAL IMMEDIATE SIDE-SHIFT PERMITS LONGER CUSPS


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SHORT CUSPS MAY BE INCREASED IN LENGTH BYINCREASING THE EFFECTS OF ANTERIOR GUIDANCE

REDUCING OVERJET

INCREASING OVERBITE


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INCISAL GUIDANCE

Can be increased

Has > influence on cusps

Further from power source

Has > proprioception


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INTRODUCTION TO OCCLUSION

TYPES OF OCCLUSION


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TYPES OF OCCLUSION

BILATERALLY BALANCED

UNILATERALLY BALANCED (GROUP FUNCTION)

MUTUALLY PROTECTED (CANINE GUIDANCE)


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BILATERAL BALANCEDOCCLUSION

USED PRIMARILY IN REMOVABLEPROSTHETICS

A MAXIMUM NUMBER OF TEETH SHOULDCONTACT IN ALL EXCURSIVE MOVEMENTS

USEFULL TO PREVENT TIPPING OFDENTURES

WILL CAUSE EXCESSIVE WEAR TO NATURALTEETH


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Maximal IntercuspationView


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Protrusive View


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Right Working View


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Left Working View


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UNILATERALLY BALANCEDOCCLUSION

Group Function

Elimination of all contacts on the non-

working side More than one tooth on the working side is

in contact during lateral excursions

Distributes the occlusal load ACTIVATES/TRIGGERS MORE MUSCLE FIBERS

(**not a good thing)


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UNILATERAL BALANCED

OCCLUSION/ Group Function


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Anterior Guidance

Canine Guidance aka. Cuspid Rise

Anterior teeth bear all the load in excursivemovements of the mandible.

Posterior teeth are discluded in all excursive

movements


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MUTUALLY PROTECTEDOCCLUSION

Anterior teeth protect the posterior teeth inall excursive movements of the mandible.(Working, Non-working, Protrusive, etc.)

Posterior teeth protect the anterior teeth in

the Maximal Intercuspal Position (MIP)


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MUTALLY PROTECTED

OCCLUSION


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WHY USE ANTERIORGUIDED OCCLUSION?

FORCE IS MORE FAVORABLY PLACED ON TEETH

CLASS THREE LEVER IS THE LEAST EFFICIENT ANDTHUS LESS FORCE PLACED ON THE ANTERIORTEETH


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POSTERIOR VS ANTERIOR

OCCLUSAL FORCE


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LEVER TYPES

CLASS I LEVER SIMILAR TO A CROWBARPOWER FULCRUM WORK

CLASS II LEVER SIMILAR TO A WHEELBARROW

FULCRUM WORK POWER

CLASS III LEVERSIMILAR TO A DRAWBRIDGE

FULCRUM POWER WORK

CONDYLE MUSCLE ANTERIOR TEETH


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Lever Class I: Crowbar


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Lever Class I


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Lever Class I: MostPowerful


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Lever Class II:WheelBarrow


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Lever Class III: Chopsticks


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CRITERIA FOR OPTIMUMOCCLUSION

5 Criteria


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1. Stable contacts are established between theteeth when the condyles are in their mostanterior, superior, middle-most position.(MIP=CR)

2 An anterior g idance that is in harmon


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2. An anterior guidance that is in harmony

with the border movements of the

envelope of function


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3. Disclusion of all posterior teeth in theprotrusive movement


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4. Disclusion of all posterior teeth on the

Non-Working Side


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5. Disclusion of all posterior teeth on the

Working Side


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In Review

Cusp height determinants

Types of Occlusal Schemes

Lever Classifications

Optimal Occlusion Principles

Documents

Occulsal Morphology Determinants