Muscles of Mastication

Question 1

What are the 4 main muscles of mastication?

Answer 1

Temporalis
Masseter
Medial Pterygoid
Lateral Pterygoid

Question 2

Which osteological regions are relevant for muscles of mastication?

Answer 2

Temporomandibular joint
Temporal fossa
Infratemporal fossa

Question 3

What two bony landmarks articulate at the temporomandibular joint?

Answer 3

Mandibular fossa of temporal bone

Head of condyloid process of mandible

Question 4

What movements are associated with the temporomandibular joint?

Answer 4

Elevation (close mouth)
Depression (open mouth)
Protrusion (protrude chin)
Retrusion (retrude chin)
Lateral movements (grinding and chewing)

Question 5

Describe the temporal fossa.

Answer 5

Depressed area on side of skull

Superior to infratemporal fossa

Question 6

Which muscle occupies the temporal fossa?

Answer 6

Upper portion of temporalis muscle

Question 7

Where is the infratemporal fossa located?

Answer 7

Medial/deep and inferior to zygomatic arch

Question 8

Which osteological landmarks are relevant to the infratemporal fossa?

Answer 8

Ramus of mandible
Lateral pterygoid plate
Maxilla
Inferior surface of greater wing of sphenoid
Mastoid and styloid processes of temporal bone

Question 9

What makes up the medial wall of the infratemporal fossa?

Answer 9

Lateral pterygoid plate

Question 10

What makes up the anterior wall of the infratemporal fossa?

Answer 10

Maxilla

Question 11

What makes up the roof of the infratemporal fossa?

Answer 11

Greater wing of sphenoid bone

Squamous part of temporal bone

Question 12

What makes up the lateral wall of the infratemporal fossa?

Answer 12

Ramus of mandible

Question 13

What is the significance of foramen ovale in the infratemporal fossa?

Answer 13

Root which nerve that innervates muscles of mastication passes through to the infratemporal fossa

Question 14

Which nerve innervates muscles of mastication?

Answer 14

Trigeminal nerve - mandibular division (V3)

Question 15

Where is the foramen ovale found in the infratemporal fossa?

Answer 15

Deep and posterior

Question 16

Where is the tuberosity of the maxilla found?

Answer 16

Lateral to hard palate, posterior to alveolar processes

Question 17

Where does masseter originate?

Answer 17

Zygomatic bone

Zygomatic arch

Question 18

Where does masseter insert?

Answer 18

Ramus of mandible: angle and lateral surface

Question 19

What are the two heads of masseter?

Answer 19

Deep and superficial heads

Question 20

How does the deep head of masseter run?

Answer 20

Vertically

Question 21

How does the superficial head of masseter run?

Answer 21

Oblique

Question 22

What functions does masseter perform?

Answer 22

Elevate and protrude mandible

Question 23

Which head of masseter elevates the mandible?

Answer 23

Deep head

Question 24

Which head of masseter protrudes the mandible?

Answer 24

Superficial head

Question 25

Where does temporalis originate?

Answer 25

Temporal fossa (superior temporal line)

Question 26

Where does temporalis insert?

Answer 26

Coronoid process of mandible (apex and medial surface)

Question 27

What functions does temporalis do?

Answer 27

Elevate and retract mandible

Question 28

What are the two heads of the lateral pterygoid muscle?

Answer 28

Superior and inferior heads

Question 29

What are the two heads of the medial pterygoid muscle?

Answer 29

Superficial and deep heads

Question 30

Where does the superior head of lateral pterygoid muscle originate?

Answer 30

Greater wing of sphenoid bone

Question 31

Where does the inferior head of lateral pterygoid muscle originate?

Answer 31

Lateral surface of lateral pterygoid plate

Question 32

Where do the 2 heads of lateral pterygoid muscle insert?

Answer 32

Region of temporomandibular joint | Neck of condyloid process of mandible

Question 33

Together, what do the two heads of the lateral pterygoid muscle do?

Answer 33

Protrude mandible

Question 34

Acting alone and alternatively, what do the two heads of the lateral pterygoid muscle do?

Answer 34

Produce side to side movement

Question 35

Where does the deep head of the medial pterygoid muscle originate?

Answer 35

Medial surface of lateral pterygoid plate

Question 36

Where does the superficial head of the medial pterygoid muscle originate?

Answer 36

Tuberosity of maxilla

Question 37

Where do the two heads of the medial pterygoid muscle insert?

Answer 37

Medial surface of mandible

Question 38

Acting together, what do the two heads of the medial pterygoid muscle do?

Answer 38

Elevate and protrude mandible

Question 39

Acting alone and alternatively, what do the two heads of the medial pterygoid muscle do?

Answer 39

Produce a grinding motion (side to side)

Question 40

Which two muscles form a muscular sling around the mandible?

Answer 40

Medial pterygoid muscle | Masseter