TMJ/Muscles

Question 1

3 parts of the TMJ

Answer 1

• mandibular condyle
• articular fossa and eminence (of the temporal bone)
• articular disc

Question 2

the mandibular condyle has greater dimension _____ than _____

Answer 2

mediolaterally; anteroposteriorly

Question 3

the ____ is the functioning portion and the ____ is the nonfunctioning portion of the TMJ

Answer 3

articular eminence; articular fossa

Question 4

4 ligaments of the TMJ

Answer 4

• fibrous capsule (capsular ligament)
• lateral ligament (formerly TMJ ligament)
• stylomandibular ligament
• sphenomandibular ligament

Question 5

muscles involved in mastrication

Answer 5

• masseter mm.
• temporalis mm.
• medial pterygoid mm.
• lateral pterygoid mm.

Question 6

function of masseter m.

Answer 6

to elevate the mandible (close the mouth) and apply great power in crushing food

Question 7

origin of the masseter

Answer 7

zygomatic arch

Question 8

insertion of the masseter

Answer 8

lateral surface of the rami and angle of the mandible

Question 9

function of the temporalis mm.

Answer 9

to elevate and position (retrude) the mandible

Question 10

____ fibers of temporalis elevate the mandible and close the teeth

Answer 10

anterior and middle vertical fibers

Question 11

____ fibers of temporalis retrude the mandible

Answer 11

posterior/horizontal

Question 12

origin of temporalis m.

Answer 12

temporal fossa

Question 13

insertion of the temporalis m.

Answer 13

coronoid process, temporal crest, and the anterior border of the ramus

Question 14

function of medial pterygoid m.

Answer 14

elevate the mandible or close teeth together

Question 15

origin of medial pterygoid m.

Answer 15

medial surface of the lateral pterygoid plate and the pterygoid fossa of the sphenoid bone

Question 16

insertion of the medial pterygoid m.

Answer 16

medial angle of the mandible

Question 17

one lateral pterygoid m. alone moves the mandible ____; both muscles together ____ or ____ the mandible

Answer 17

laterally; protrude; depress

Question 18

origin of lateral pterygoid m.

Answer 18

superior head attaches to the infratemporal space of the greater wing of the sphenoid bone
inferior head attaches to lateral surface of lateral pterygoid plate of the sphenoid bone

Question 19

insertion of lateral pterygoid m.

Answer 19

pterygoid fovea (on the front of the neck of the condyloid process) and the anterior part of the articular disc

Question 20

suprahyoid mm.

Answer 20

• geniohyoid
• mylohyoid
• digastric

Question 21

infrahyoid mm.

Answer 21

• omohyoid

- sternohyoid

Question 22

working together, the suprahyoids and infrahyoids can all ___ the mouth, ____ the mandible

Answer 22

open; depressing

Question 23

other factors affecting position or movement

Answer 23

• ligaments
• fascia
• muscles of facial expression

Question 24

muscles of facial expression

Answer 24

• orbicularis oris m.
• buccinator m.
• upper oral group (upper lip)
• lower oral group (lower lip)

Question 25

upper lip muscles

Answer 25

• zygomaticus major and minor
• levator labii superioris
• levator anguli oris

Question 26

lower lip mm.

Answer 26

depressor labii inferior
depressor anguli oris
mentalis

Question 27

muscles that elevate the mandible

Answer 27

• masseter mm.
• temporalis mm. (anterior vertical and middle fibers)
• medial pterygoid mm.

Question 28

muscles that depress the mandible

Answer 28

• both lateral pterygoids

- supra and infrahyoid mm. together

Question 29

muscles that retrude the mandible

Answer 29

• temporalis m. (posterior horizontal fibers)

- suprahyoids (with help from infrahyoids)

Question 30

muscles that protrude the mandible

Answer 30

-both lateral pterygoid mm. simultaneously

Question 31

muscles involved in lateral excursion of the mandible

Answer 31

-right lateral pterygoid moves mandible to the left, left lateral pterygoid moves mandible to the right

Question 32

innervation to the muscles of mastication

Answer 32

trigeminal n. (CN V) - the mandibular n. (division III)

Question 33

innervation of muscles of facial expression

Answer 33

facial n. (CN VII)