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EDENTULOUS STATEBucher2013

Chap.1

Etiology: heterogeneous dental diseases ,culture ,financial,attitude

Prevalance : but partially dentate

EDENTULOUS STATE

1)Need for complete denture remain high

2)High percentage of older people be edentoulus

3)Impact of longivity on edentulism ?

4) Difficult treatment

EDENTULOUS STATE

Periodontium: hard CT& soft CT

Principal functions: 1)support

2)positional adjustmentSecondary & dependent function: sensory perception

SUPPORT OF NATURAL DENTITION

Quality : Mucosal vs periodontium

Quantity: max:22.96 vs 45cm²mand:12.25

denture-bearing area (basal seat) becomes smaller as ridges resorbs

mucosa :little tolerance /adaptability to denture wearing

Systemic diseases: Anemia, hypertension , diabetes , nutritional deficencies

Support for complete denture

intermittent , rhythmic and dynamic

greatest forces : mastication & deglutiton vertically in direction tongue & circumoral musculature: lower,longer,horizontally

Physiological forces

Increase steadily & abruptly return to zero magnitude , rise time , interval between thrust consistency , stage of chewing, dental status

Physiological forces

function :17.5 min per daymastication(9min) < deglutition

Parafunction : (grinding , clenching,bruxism)

occlusal forces

Natural dentition: 200 N

Complete denturers : max:60-80 N 5-6 times less

masticatory forces ~ type foodFood choice ~ tissue tolerance

Masticatory loads

The residual ridge consists of denture-bearing mucosa, the submucosa and periosteum, and the underlying residual alveolar bone

Residual Ridge :

Residual Ridges

Tensile compressive

Vertical & horizontal

1)Direct effect of loss of pdl

2)Poorly understood factors

Ridge Resorption

More rapid in ant.mand Functional movement may be a major cause(unproved)

"principles" of complete denture construction:

1)minimize the forces transmitted to the supporting structures

2) to decrease the movement of the prostheses

physical factors

1)maximal extension of the denture base(impression)

2) maximal intimate contact (impression)

3)frequent follow up(reline)

muscular effect(neutral zone) buccinator ,orbicularis oris,intinsic&extrinsic muscles of tongue

Psychological effect salaiva

retention

The edentulous state

Deteriorating adult dentition

Healthy adult

Developing dentition

Development & adaptation of the occlusion

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it has been concluded that masticatory efficiency as low as 25% is adequate for complete digestion

of foods

Patients do not compensate for the smaller number of teeth by more prolonged or a larger number of chewing strokes

they merely swallow larger food particles

d

Loss of teeth

diminished masticatory efficency Restrict dietary choice

Systemic effect

• Quality of prosthetic service is related to

dentuer wearer masticatory performance

mandibular movement of dentate & denturers is similar treatment of partially edentulous and

edentulous patients:

chewing efficiency improve masticatory muscle activity

elevator muscle activity & occlusion phase

Chewing occurs chiefly in the premolar and molar regions

both right and left sides are used to about the same extent

the tougher the consistency the greater is the person’s preference for using the

premolar region

The end… Thanks for your patienceAny question? …

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