Muscles that insert into the Modiolus

Question 1

What are the functions of the orbicularis oris?

Answer 1

1. Purses lips and presses them against lips
2. Sphincter action of the lips
3. Pulls the skin medially at dermal injection points

Question 2

What is the orbicularis oris composed of?

Answer 2

• Long vertical segments that curl outward -> marginal protrusion

Question 3

What facial branches innervate the orbicularis oris?

Answer 3

1. Buccal
2. Mandibular

Question 4

In the upper lip, where does the orbicularis oris insert?

Answer 4

• Approx. 4-5 mm lateral from the midline (sparing the central region)

Question 5

What is the function of the levator anguli oris?

Answer 5

Ellevates the commussure

Question 6

Where does the levator anguli oris arise from?

Answer 6

Canine fossa of the maxilla beneath the infraorbital foramen

Question 7

What facial nerves innervates the levator anguli oris?

Answer 7

1. Buccal
2. Zygomatic

Question 8

What nerve and artery travel on the superficial surface of the levator anguli oris?

Answer 8

1. Facial artery
2. Infraorbital nerve

Question 9

When contracted, what does the zygomaticus major do?

Answer 9

Elevates and laterally moves the commissure

Question 10

Where does the zygomaticus major muscle arise from?

Answer 10

Zygomatic bone

(anterior to the zygomaticotemporal suture line and passes inferiorily and medially over the buccinator andlevator anguli oris)

Question 11

Where does the zygomaticus major muscle insert?

Answer 11

Modiolus

Question 12

The zygomaticus major inervates which branches of the facial nerve?

Answer 12

1. Zygomatic
2. Buccal

Question 13

Describe the fibers of the zygomaticus major: supperiorly and inferiorily

Answer 13

Superiorily: deep to the orbicularis oculi muscle

Inferiorily: superficial to the facial vesselsandfacial nerve

Question 14

Where are the 3 places that the buccinator arises from?

Answer 14

1. Posterior alveolar process of the maxilla
2. Ptergomandibular raphe
3. Body of mandible

Question 15

What is the function of the buccinator?

Answer 15

1. Press lips and cheeks against teeth

Question 16

What branch of the facial nerve does the buccinator innervate?

Answer 16

Buccal branches

Question 17

What duct pierces the buccinator after it crosses the anterior edge of the masseter muscle?

Answer 17

Parotid

Question 18

Where does the risorius arise from?

Answer 18

Parotid fascia

Question 19

Where does the risorius insert?

Answer 19

Modiolus

Question 20

What facial nerve branch does risorius innervate with?

Answer 20

Buccal branch

Question 21

What happens when the risorius contracts?

Answer 21

Sardonic smile

Question 22

Where does the depressor anguli oris arise from?

Answer 22

The oblique line on the anterior mandible below the canine and premolarteeth

Question 23

Where does the depressor anguli oris insert?

Answer 23

Modiolus

Question 24

What facial nerve is innervated by the depressor anguli oris?

Answer 24

Mandibular branch

(enters muscle on its deep surface)

Question 25

What is the function of the depressor anguli oris?

Answer 25

Depress and laterally move the commissure

Question 26

What is the platysma pars modiolaris?

Answer 26

Part of the platysma that is posterolateral to the depressor anguli oris, deep to the risorius

Question 27

Where does the platysma pars modiolaris insert?

Answer 27

Muscles of lateral lowerlip

Question 28

What does the platysma pars modiolaris do?

Answer 28

Depressor of the lower lip