oral function 1: muscles

Question 1

what is the origin of masseter?

Answer 1

zygomatic arch

Question 2

what is the insertion of masseter?

Answer 2

lateral surface and angle of mandible

Question 3

what is the action of masseter?

Answer 3

elevates mandible

Question 4

how is masseter examined?

Answer 4

place one finger intra-orally and the other on the cheek

Question 5

what is the origin of temporalis?

Answer 5

floor of temporal fossa

Question 6

what is the insertion of temporalis?

Answer 6

coronoid process and anterior border of ramus

Question 7

what is the action of temporalis?

Answer 7

elevates and retracts mandible

Question 8

when is masseter tender?

Answer 8

px who have a clenching habit

Question 9

when is temporalis tender?

Answer 9

px who have a bruxist habit

Question 10

how to examine temporalis?

Answer 10

palpate origin by asking px to clench
digital palpation between superior and inferior temporal lines just above ear, extending forwards towards supra-orbital region

Question 11

what is the origin of lateral pterygoid?

Answer 11

from lateral surface of lateral pterygoid plate

Question 12

what is the insertion of lateral pterygoid?

Answer 12

anterior border of the condyle and intra-anticular disc via 2 independent heads

Question 13

what is the function of lateral pterygoid?

Answer 13

protrudes and laterally deviates mandible and inferior head functions with mandibular depressors during openings

Question 14

where does the inferior belly of the lateral pterygoid attach?

Answer 14

head of condyle

Question 15

where does the superior belly insert?

Answer 15

intra-articular disc

Question 16

how do you examine the lateral pterygoid?

Answer 16

response to resisted movement

-hand on mandible and top of head, open mouth

Question 17

what is the the origin of the deep head of the medial pterygoid?

Answer 17

medial surface of lateral pterygoid

Question 18

what is the origin of the superficial head of the medial pterygoid?

Answer 18

tuberosity of maxilla

Question 19

what is the action of the medial pterygoid?

Answer 19

elevates and assists in protrusion of the mandible

Question 20

how to examine the medial pterygoid?

Answer 20

not possible

Question 21

what are the movements of the TMJ?

Answer 21

rotation-initial opening

translation - wider opening

Question 22

what kind of movement is rotation?

Answer 22

hinge

Question 23

what kind of movement is translation?

Answer 23

sliding

wider opening: protrusive or retrusive movements

Question 24

describe protrusion

Answer 24

both condyles leave their fossae and move forward along the articular eminences

Question 25

describe retrusion

Answer 25

both condyles leave eminences and move back into their respective fossae

Question 26

what shape is formed by rotation + translation?

Answer 26

ennvelope

Question 27

what are the maximum biting forces between molars?

Answer 27

200-700N

Question 28

what factors can limit maximum biting force recorded?

Answer 28

psychological -fear of tooth fracture muscle mass -mass increased by parafunction- bruxism

Question 29

what are the muscle fibre types?

Answer 29

type 1 slow, low forces type 2 fast, stronger forces

Question 30

what causes predominant fibre type?

Answer 30

jaw morphology and diet

Question 31

what kind of people can generate stronger bite forces?

Answer 31

squarer jaws with more type 2 fibres

Question 32

what teeth are the greatest bite forces generated on?

Answer 32

1st molars

Question 33

what are the infrahyoid muscles?

Answer 33

sternohyoid omohyoid thyrohyoid sternothyroid

Question 34

what are the suprahyoid muscles?

Answer 34

digastric mylohyoid geniohyoid stylohyoid

Question 35

what muscles act as jaw depressors when the hyoid bone is fixed by contraction of the infrahyoids?

Answer 35

digastric mylohyoid geniohyoid

Question 36

what are the 2 types of tongue muscles?

Answer 36

intrinsic | extrinsic

Question 37

describe intrinsic muscles

Answer 37

alter shape of tongue longitudinal vertical transverse

Question 38

describe extrinsic muscles?

Answer 38

``` alter shape and position genioglossus hypoglossus palatoglossus styloglossus ```

Question 39

what facial muscles control food bolus and prevent spillage?

Answer 39

orbicularis oris | buccinator