Oral Functions: Muscles

Question 1

what is the origin of the masseter?

Answer 1

zygomatic arch

Question 2

what is the insertion of the masseter?

Answer 2

lateral surface and angle of mandible

Question 3

what does the masseter do?

Answer 3

elevates mandible

Question 4

which type of patients have tender masseters?

Answer 4

clenching patients

Question 5

how do you examine the masseter?

Answer 5

one finger intra-orally and the other on the cheek

Question 6

what is the origin of the temporalis?

Answer 6

floor of temporal fossa

Question 7

what is the insertion of the temporalis?

Answer 7

coronoid process and anterior border of ramus

Question 8

what does the temporalis do?

Answer 8

elevates and retracts the mandible

Question 9

which patients have a tender temporalis?

Answer 9

bruxism patients

Question 10

how do you palpate the temporalis?

Answer 10

ask the patient to clench teeth together

Question 11

what is the origin of the lateral pterygoid?

Answer 11

from the lateral surface of the lateral pterygoid plate

Question 12

what is the insertion of the lateral pterygoid

Answer 12

anterior border of the condyle and intra-articular disc via two independent heads

Question 13

what is the function of the lateral pterygoid?

Answer 13

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

Question 14

what does the inferior belly of the lateral pterygoid attach to?

Answer 14

head of condyle

Question 15

what does the superior belly of the lateral pterygoid attach to?

Answer 15

intra-articular disc

Question 16

which muscles is it not possible to manually palpate

Answer 16

lateral pterygoid and medial pterygoid

Question 17

how do you examine the lateral pterygoid

Answer 17

response to resisted movement, one hand on patient head and other under chin and ask them to open mouth

Question 18

what is the origin of the medial pterygoid?

Answer 18

deep head: medial surface of the lateral pterygoid plate

superficial head: tuberosity of maxilla

Question 19

where is the insertion of the medial pterygoid?

Answer 19

medial surface of angle of mandible

Question 20

what is the action of the medial pterygoid?

Answer 20

elevates and assists in protrusion of the mandible

Question 21

which muscle cannot be examined?

Answer 21

medial pterygoid

Question 22

what might happen if hitting the medial pterygoid with LA ?

Answer 22

trismus

Question 23

what are the movements of the TMJ

Answer 23

rotation (initial opening) and translation (wider opening)

Question 24

what sort of movement does the initial opening of the mouth have

Answer 24

a hinge movement

Question 25

what sort of movements does the wider opening of the mouth have?

Answer 25

protrusive and retrusive sliding movements

Question 26

what happens to the condyles during protrusion?

Answer 26

they leave their fossae and move forward along the articular eminences (opposite for retrusion)

Question 27

what is Posselt's envelops of motion?

Answer 27

the range of motion of the lower jaw bone. A diagrammatic representation of a sagittal view of maximum mandibular movement

Question 28

what is the maximum biting forces between molars?

Answer 28

200-700N

Question 29

which factors affect maximum bite force/

Answer 29

psychological - fear of fracture muscle mass - bigger muscles = larger force parafunction = bruxism

Question 30

what is type 1 muscles

Answer 30

slow, low forces

Question 31

what is type 2 muscles

Answer 31

fast, strong forces

Question 32

which type of muscle fibre do people with squarer jaws have more of?

Answer 32

type 2

Question 33

where is the greatest bite force generated?

Answer 33

between 1st molars

Question 34

why do 1st molars have the greatest bite force?

Answer 34

as they have a positive relation to the TMJ and muscles (are nearer the force generating muscles and the fulcrum (TMJ))

Question 35

what are the suprahyoid muscles?

Answer 35

digastric, mylohyoid, geniohyoid, stylohyoid

Question 36

what are the infrahyoid muscles

Answer 36

sternohyoid, omohyoid, thyrohyoid, sternothyroid

Question 37

what do intrinsic tongue muscles do?

Answer 37

alter shape

Question 38

what are the intrinsic tongue muscles?

Answer 38

longitudinal, vertical, transverse

Question 39

what are the extrinsic tongue muscles?

Answer 39

genioglossus, hypoglossus, palatoglossus, styloglossus

Question 40

what do the extrinsic tongue muscles do?

Answer 40

alter shape and position

Question 41

which muscles help to control food bolus and prevent spillage?

Answer 41

orbicularis oris and buccinator