32. Functional and age changes in the masticatory apparatus. Attrition. Abrasion. Erosion.

whats in it

Masticatory apparatus consists of:
Physiological and Functional changes in masticatory apparatus:

Phases of dental Ware-out:

Dental erosion can be caused by:

age and change in masticatory apparatus

attrition, abrasion, erosion

Masticatory apparatus consists of:

SUPPORTING PART -

SECRETORY PART = GLANDS

SOFT TISSUE = CHEEKS, LIPS, MUCOSA, SKIN

MOTOR = MIMIC AND CHEWING MUSCLES

NEUROTROPHIC PART = blood, neuro, lymphatic system

(5) Physiological and Functional changes in masticatory apparatus:

1. Occlusal surface of the dental crown becomes worn out from abrasion

2. Ontogenetic parodontal changes

3. Tooth (teeth loss)

• -  ADENTIO! NOT ATTRITO partialis (partial tooth loss)

• -  Adentio totalis (total tooth loss)

• -  In general tooth loss leads to dental arch defects (Godons phenomenon)

4. TMJ functional changes

• -  Costens syndrome – this pain is caused by hypertonia (too much muscle tone) of the

  masticatory apparatus which projects into various regions of the head and neck

• -  Condyle angle decreases

• -  Sliding protrusive movements dominate

5. Muscle functional status changes
- Attrition and Abrasion leads to hypertrophy of masseter and the temporal muscle

phases of dental ware out

Phases

of dental Ware-out:

1. Compensatory phase

• -  ATTRITO DENTIS! NOT DENTIN this only affects the enamel

• -  The occlusal contacts become facets up to 4mm (wear facets are flattened areas

  caused by physiological or parafunctional contacts of opposing teeth)

• -  Chewing efficiency decreases

• -  Ps (specific chewing force) gradually increases

2. Sub compensatory phase
- ATTRITO DENTIS CUM ABRASIONE, this affects the tooth up to the enamel-

dentin junction

3. Decompensation

- ABRASIO DENTIS – contains 4 stages

Dental erosion can be caused by:

Mechanical irritants – hard toothbrush, abrasive pastes, parafunctions Chemical irritants
Thermal irritants

age changes in masticatory apparatus:

Sensory system deteriorates as age increases which means senses of smell and taste is affected, as well as hearing is impaired
Motor system deteriorates as age increases. Impairment of the masseter and medial pterygoid muscle suffer a decrease of cross-sectional area and the muscle density decreases as age increases
Epithelium becomes thinner
Connective tissue is less resilient and the ability for mucosa to heal is impaired

Attrition

• -  Dental attrition is the tooth wear caused by tooth-on-tooth contact

• -  This type of tooth wear is normal age process

• -  More rapid attrition could be caused by larger dental problemsAttrition

  • Abrasion

    • -  The process of losing enamel due to some sort of outside mechanical action

    • -  In other words; teeth being physically worn down by external force

      Erosion

    • -  This is a type of tissue loss

    • -  It is the chemical loss of mineralised tooth substance caused by chemical irritants

      (acids)