Lecture 10: Deep Face/Infratemporal Fossa

Question 1

Where are the temporal and Infratemporal fossae found in relation to the zygomatic arch?

Answer 1

Temporal fossa is the space superior to the arch

Infratemporal fossa is the space inferior to the arch

Question 2

What are the boundaries of the infratemporal fossa?

Answer 2

Lateral = ramus of mandible

Anterior = maxilla

Medial = lateral pterygoid plate

Roof = sphenoid (greater wing)

Posterior = tympanic plate & mastoid & styloid processes

Inferior = angle of mandible

Question 3

What are the contents of the infratemporal fossa

Answer 3

Inferior portion of temporalis m

Lateral and medial pterygoid muscles

Maxillary a

Pterygoid venous plexus

Nervous structures

Question 4

What nervous structures are found in the infratemporal fossa?

Answer 4

Inferior alveolar n (V3)
Lingual n (V3)
Buccal n (V3)
Chorda tympani (CNVII)
Otic ganglion

Question 5

What are teh branches of the mandibular part of the maxillary artery?

Answer 5

Deep auricular a
Anterior tympanic a
Inferior alveolar a -> branches to mylohyoid and mental

Middle meningeal a
Accessory meningeal a

Question 6

What are the branches of the pterygoid part of the maxillary a?

Answer 6

Deep temporal a
Pterygoid branches
Masseteric a
Buccal a

Question 7

Where does the maxillary artery run in relation to the buccal nerve?

Answer 7

Medial to it

Question 8

Where does the maxillary artery run in relation to the lingual nerve and inferior alveolar nerve?

Answer 8

Lateral to them

**Can run medial to lingual sometimes

Question 9

Where does the maxillary artery run in relation to the mandibular n (V3)?

Answer 9

Medial to it

Question 10

What nerve innervates the muscles of mastication?

Answer 10

Trigeminal nerve (CN V3)

Question 11

What are the 4 paired muscles of mastication?

Answer 11

Temporalis
Masseter
Lateral pterygoid
Medial pterygoid

Question 12

What is the action of the masseter muscle?

Answer 12

Elevates mandible and assists in protraction, retraction and side-to-side motion

**KNOW: closes jaw!

Question 13

What is the action of the temporalis m?

Answer 13

Vertical fibers elevate mandible

Horizontal fibers retract mandible

Unilateral: lateral movement of mandible -> chewing

Question 14

What is the bilateral action of the lateral pterygoid muscles?

Answer 14

Protrudes mandible and opens mouth

Question 15

What is the unilateral action of the lateral pterygoid muscles?

Answer 15

Alternating actions, along with ipsilateral medial pterygoid, result in side-to-side movements necessary for grinding

Question 16

What are the bilateral actions of the medial pterygoid muscles?

Answer 16

Elevation of mandible and also act with lateral pterygoid muscles to assist in protrusion of mandible

Question 17

What are the bilateral actions of the medial pterygoid muscles?

Answer 17

Acts with ipsilateral lateral pterygoid muscles to protrude mandible and produce medial movement towards the opposite side

Alternating actions between left and right sides results in grinding

Question 18

What is the digastric muscle innervated by?

Answer 18

Anterior belly = nerve to mylohyoid (from mandibular nerve of CN V)

Posterior belly = facial n (CN VII)

Question 19

What are the actions of the digastric muscle?

Answer 19

Elevates hyoid bone during swallowing and assists in opening the mandible

Question 20

What is the action of the geniohyoid muscle?

Answer 20

Draws hyoid bone forward during swallowing and assists in opening the mandible

Question 21

What are the actions of the mylohyoid m?

Answer 21

Tightens and elevates oral floor
Draws hyoid bone forward during swallowing
Assists in opening mandible and moving it from side to side

Question 22

What are the actions of the stylohyoid m?

Answer 22

Elevates hyoid bone during swallowing

Assists in opening the mandible

Question 23

What nerve innervates the stylohyoid m?

Answer 23

Facial nerve (CN VII)

Question 24

What muscles open the mandible?

Answer 24

Digastric
Geniohyoid
Mylohyoid
Stylohyoid

Question 25

What is the action of the sternohyoid m?

Answer 25

Depresses hyoid bone

Depresses larynx and hyoid bone for phonation and terminal phase of swallowing

Question 26

What are the actions of the sternothyroid m?

Answer 26

Draws larynx and hyoid bone downward

Depresses larynx and hyoid bone for phonation and terminal phase of swallowing

Question 27

What are the actions of the thyrohyoid m?

Answer 27

Depresses and fixes hyoid bone

Raises larynx during swallowing

Question 28

What are the actions of the omohyoid m?

Answer 28

Depresses the hyoid bone
Draws larynx and hyoid bone downward for phonation and terminal phase of swallowing
Tenses cervical fascia with its intermediate tendon and maintains latency of internal jugular v

Question 29

What muscles are responsible for elevation of the mandible?

Answer 29

Temporalis
Masseter
Medial pterygoids

Question 30

What muscles are responsible for depression of the mandible?

Answer 30

Lateral pterygoids

Suprahyoid and infrahyoid

Question 31

What muscles are responsible for protrusion of the mandible?

Answer 31

Lateral pterygoids
Masseter
Medial pterygoids

Question 32

What muscles are responsible fore retrusion of the mandible?

Answer 32

Temporalis

Masseter

Question 33

What 2 ligaments limit inferior excursion at TMJ?

Answer 33

Sphenomandibular ligament

Stylomandibular ligament

Question 34

An inferior alveolar nerve block blocks sensation to what structures?

Answer 34

Lower teeth

**Injection side is just above 3rd molar

Question 35

How do you block sensation to the upper teeth?

Answer 35

Superior alveolar nerve block to region being anesthesized

**Different from bottom teeth where you inject above 3rd molar and all sensation is lost