esthetic and occlusal considertions

7/29/2019 Esthetic and Occlusal Considertions

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Esthetic consideration ingingival tissue

management


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THE ELEMENTS OF THE OCCLUSAL EQUATION

Occlusion in the natural dentition is characterized by the

following features:

Highly variable occlusal schemes

In many cases, a high degree of adaptation

Can be satisfactory even when several teeth aremissing

The mandible flexes during maximal opening andprotrusion

The condyle can shift causing interferences withposterior morphology (Bennett movement)

The patients envelope of function varies with thepatients position and activity


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Occlusion that is developed in a prosthetic

rehabilitation should have the following features:

Mutual protection between anterior teeth and

posterior teeth, teeth on the working side and

teeth on the non-working side

Bilateral posterior contact

Efficient anterior guidance that discludes all

posterior teeth

Canine guidance or group function

Muscular comfort


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The determinants of occlusion can be divided in anterior and posterior:

ANTERIOR

Overbite

Overjet

POSTERIOR

Intercondylar distance

Condylar guidance

Side shift (ISS, PSS)

Curve of Wilson

Curve of Spee

Occlusal plane inclination


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Anterior guidance

the influence of the contacting surfaces of teethon tooth limiting mandibular movements

It is the consequence of the interaction between

overbite and overjet which influence its efficacy

The less effective the incisal guidance, the more

important are the posterior determinants

of occlusion.


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Overbite


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Overjet


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MagnitudeWidening of periodontal ligament space

Increase in number and width of the periodontal fibersIncrease in density of alveolar bone

DirectionReorientation of stresses and strains withinperiodontium

Lateral and torque forces injure the periodontium

DurationConstant pressure is more injurious than intermittentpressure

FrequencyThe more frequent the application of an intermittentforce, the more injurious


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Excessive occlusal forces

Disrupt the function of the masticatory

musculature

Cause painful muscle spasmsInjure temporomandibular joint

Produce excessive tooth wear


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Acute trauma

Results from an abrupt occlusal impact

Biting on a hard object (cherry seeds)

New tooth restorations or prostheses

Chronic trauma

Develops from gradual changes in occlusion

Produced by tooth wear, drifting of teeth,

extrusion, parafunctional habits


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Traumatic occlusal relationships a.k.a.

Occlusal disharmony

Functional imbalance

Occlusal dystrophy


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Primary trauma from occlusion

Result of alterations in occlusal forces

High restorative fillings

Isertion of prosthesis that creates excessive forceson abutments and antagonists

Normal periodontium with normal height of bone


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Secondary trauma from occlusion

Reduced ability of the tissues to resist occlusal

forces

Adaptive capacity of tissues are impaired dueperiodontal inflammation that results to bone loss

Periodontium becomes more vulnerable to injury

Normal periodontium with normal height of bone

Marginal periodontitis with reduced height of bone


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Stages of Tissue Response

Injury

Repair

Adaptive remodeling


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Injury

Produced by excessive occlusl forces

Chronic force periodontium is remodeled to cushion

impact

Periodontal ligament is widened at the expense of the

bone, results in nagular defects withoiut periodontal

pockets

Tooth becomes loose

Furcations most susceptible to injury of the

periodonitum


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Repair

Constantly occuring in the normal periodontium

Trauma from occlusion stimulates reparative

activity

Damaged tissues are removed

New connective tissue cells and fibers, bone and

cementum are formed to attempt restoration of

injured periodontium


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When bone is resorbed by occlusal forces, it

attempts to reinforce the thinned bony trabeculae

with new bone - buttresing bone formation

Also occurs when bone is destroyed byinflammation and osteolytic tumors


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Adaptive Remodeling of

PeriodontiumIf repair process cant keep pace with the

destruction , the periodontium is remodeled in an

effort to create structural relationship in which the

forces are no longer injurious to the tissues


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Effects of insufficient occlusal force

May also be injurious to the supporting

periodontal tissues

Hypofuntion can result from

Open-bite relationship

Ansence in functional antagonists

Unilateral chewing habits


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Insufficient stimulation causes

thinning of periodontal ligament

Atrophy of fibersOsteoporosis of alveolar bone

Reduction in alveolar bone height

esthetic and occlusal considertions

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