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Flashcards in Muscles Of Mastication Deck (32):
1

Where do masticatory movements take place

The TMJ

2

What are some in pm bony features of the TMJ

The condyle
Glenoid flossa
Articulate eminence

3

What si the movement when the jaw opens

Hinge

4

What happens when the jaw opens widely

Hinge and slide

5

What happens In a protrusion

Slide Anteriorly

6

What happens in a lateral excursion

Working side - rotation around vertical axis
Non working side - translation

7

What are the four muscles of mastication

Masseter
Temporalis
Lateral and medial pterygoid

8

What innervates the muscles of mastication

The motor root of trigeminal nerve

9

What si the most powerful muscle of mastication

The masseter

10

What is the structure of the masseter

Quadrangle in shape split into two parts deep and superficial

11

What are the attachments of the masseter

Superficial originates form maxillary process of zygomatic bone
Deep part originates form zygomatic arch if temporal bone
Both parts attach a to the ramus of mandible

12

What are the actions of the masseter

Elevates the mandible closing the mouth

13

Where does the temporal bone originate

In the temporal fossa shallow depression on lateral aspect of skull

14

What covers the temporalis

Tough fascia this can harvested surgically and used to repair tymp mem perforated

15

What are the attachments of the temporalis

Originates form temporal fossa condenses to a tendon which inserts onto coronoid orocess of mandible

16

What are h actions of the temporalis

Elevated the mandible closing the mouth
Retracts the mandible pulling jaw Posteriorly

17

What is the structure of the medial pterygoid

Quadrangle muscle with a deep and superficial head

18

Where is the medial pterygoid located

Inferior to lateral pterygoid

19

What are the attachments of the medial pterygoid

Superficial head originates form maxilla
Deep head originates from lateral pterygoid
Both parts attach to ramus of mandible near angle

20

What si the action of the medial pterygoid

Elevates the mandible closing the mouth

21

What si the shape of the lateral pterygoid

Triangular shape with two heads superior and inferior

22

What are the muscle fibres like

Horizontal

23

What do the two tendons of the lateral ptery do

Converge to a single tendon which attaches to the neck of mandible

24

What are the attachments of the lateral ptery

Superior head originates form greater wing of sphenoid
Inferior head originates form lateral otery plate of sphenoid

25

What si the action of the lateral ptery

Acting bilaterally, lateral pterygoid protract the mandible pushing the jaw forwards
Unilateral action produces side to side movement of jaw

26

What are the 3 groups of muscles used in mastication

Between skull and mandible - muscles of mastication

Between mandible and hyoid

Hyoid stabilisers

27

What are the muscles between the mandible and hyoid used for mastication

Genio hyoid c1 with hypoglossal
Mylohyoid Vc
Abd Vc

28

What are the hyoid stabilisers

Infrahyoid
PBD
Stylohyoid

29

What does the trigeminal nerve motor root do

Exit brainstem at pons
Carried with Vc
Exit skull at formen ovale
Nerves to
- masseter
- temporalis
- med ptery
- lat ptery
- mylohyoid
- Abd
- tensor palatini
- tensor tympani

30

What ar the physiological chewing forces

70-150n dentate
4-55n Edentulous

31

What are the maximum clenching forces

500-700n between molars

32

What si mastication

Chewing
Breakdown foodstuffs to prep for swallowing, increase sa for digestion, release chemicals for taste
Stimulate salivary flow