13 - Superficial face and muscles of facial expression

Question 1

What is the face?

Answer 1

Anterior aspect of the head, from forehead to chin and ear to ear

Question 2

Describe the sensory innervation of the face.

Answer 2

Supplied by the trigeminal nerve and the cervical nerves C1 and C2 vie the great auricular nerve

Question 3

Where is the CN V1 dermatome?

Answer 3

Vertex to tip of the nose, including the upper eyelids

Question 4

Where is the CN V2 dermatome?

Answer 4

Anterior temple region to upper lip, including the lower eyelids and Ala of the nose

Question 5

Where is the CN V3 dermatome?

Answer 5

Posterior temple region to the chin, including the lower lip, anterior ear and skin over the anterior parotid region

Question 6

Where does the great auricular supply on the face?

Answer 6

Skin over the angle of the mandible and the posterior parotid region

Question 7

How are the muscles of facial expression organised in the face?

Answer 7

• many are anchored to bone or fascia on one end, and skin on the other
• these take their action by pulling on the skin
• some act as dilators or sphincters around the orifices of the face

Question 8

What makes up the parotid plexus?

Answer 8

• temporal
• zygomatic
• buccal
• marginal mandibular
• cervical

Question 9

What does the temporal branch of the facial nerve supply?

Answer 9

• frontal belly of occipitofrontalis
• orbicularis oculi

Question 10

What does the zygomatic branch of the facial nerve supply?

Answer 10

• orbicularis oculi
• upper lip muscles

Question 11

What does the buccal branch of the facial nerve supply?

Answer 11

• buccinator
• orbicularis oris

Question 12

What does the marginal mandibular branch of the facial nerve supply?

Answer 12

Orbicularis oris

Question 13

What does the cervical branch of the facial nerve supply?

Answer 13

Platysma

Question 14

What does the posterior auricular branch of the facial nerve supply?

Answer 14

• occipital belly of occiptiofrontalis
• auricular muscles

Question 15

What is the origin and insertion of occipitofrontalis?

Answer 15

FRONTAL BELLY
Origin - epicranial aponeurosis
Insertion - skin of eyebrows and forehead

OCCIPITAL BELLY
Origin - lateral 2/3 of superior nuchal line
Insertion - epicranial aponeurosis

Question 16

What are the actions of occipitofrontalis?

Answer 16

Occipital belly - retract scalp
Frontal belly - wrinkle forehead and raise eyebrows

Question 17

Describe the orbicularis oculi and its actions.

Answer 17

• 2 parts, palpebral and orbital
• palpebral closes eye gently (blink reflex)
• orbital closes eye tightly (voluntary)

Question 18

What is the origin and insertion of orbicularis oculi?

Answer 18

PALPEBRAL
Origin - medial palpebral ligament
Insertion - lateral palpebral ligament

ORBITAL
Origin - nasal part of frontal bone , frontal process of maxilla and medial palpebral ligament
Insertion - skin around margin of orbit

Question 19

What is the origin and insertion of orbicularis oris?

Answer 19

Origin - partially buccinator/surrounding muscles, partially form medial side of the mandible and maxilla
Insertion - mucous membrane of lips

Question 20

What is the action of orbicularis oris?

Answer 20

• close / protrude lips
• together with surrounding muscles and tongue keep bolus in the mouth
• 1st sphincter of the GIT

Question 21

What is the origin and insertion of buccinator?

Answer 21

Origin - laterally from posterior part of alveolar process of maxilla/mandible and medially from pterygomandibular raphe
Insertion - orbicularis oris

Question 22

What is the action of buccinator?

Answer 22

• control bolus in the mouth, and direct food onto occlusal surfaces
• assist with smiling
• resists distention of sheets (ie blowing)

Question 23

What is the origin and insertion of platysma?

Answer 23

Origin - subcutaneous tissue of the infra and supraclavicular region
Insertion - base of mandible to merge with orbicularis oris, side of cheek, lower lip and angle of the mouth

Question 24

What is the action of platysma?

Answer 24

• tense inferior face / neck
• depress mandible

Question 25

What are the dilators of the mouth?

Answer 25

• levator anguli oris
• depressor anguli oris
• zygomaticus major
• zygomaticus minor
• risiorius
• levator labii superioris

Question 26

What muscle in the nose contributes to the lifting of the upper lip?

Answer 26

Levator labii superioris alaeque nasi

Question 27

What are the branches of the ICA that supply the face?

Answer 27

Ophthalmic branch
- zygomaticofacial
- zygomaticotemporal
- supraorbital
- supratrochlear

Question 28

What are the branches of the ECA that supply the face?

Answer 28

Facial
Transverse facial (branch of superficial temporal)

Maxillary
- buccal
- mental
- infraorbital

Question 29

Describe the venous drainage of the face.

Answer 29

• facial veins drain mainly to the IJV
• transverse facial vein drains some the upper face
• no valves in these veins

Question 30

Describe the retromandibular vein.

Answer 30

• deep vessel of the face
• formed by the superficial temporal and maxillary veins
• runs within parotid gland
• anterior branch joins facial vein
• posterior branch becomes EJV

Question 31

What is the danger triangle of the face?

Answer 31

• no valves in external facial veins
• blood flows in both directions
• veins deep in triangle drain cavernous sinus
• skin infections can lead to intracranial infections
• no distinct deep fascia, therefore fluid accumulates

Question 32

What are the layers of the eyelids?

Answer 32

• skin
• connective tissue
• conjunctiva
• muscle
• tarsus (eyelid support)
• orbital septum