Deep Face

Question 1

The pterion of the skull refers to the junction of what? Is it a weak or strong spot in the skull?

Answer 1

• Junction of temporal, parietal, sphenoid, and frontal bones
• Weak spot (dangerous because middle meningeal artery runs beneath)

Question 2

What does the temporalis muscle attach to and what is its function?

Answer 2

• Attaches at coronoid process of mandible

- Function is to elevate the mandible during normal talking

Question 3

Are the temporalis and masseter horizontally or vertically oriented?

Answer 3

Their fibers are vertically oriented.

Question 4

What is the origin and insertion of the masseter muscle?

Answer 4

• Origin: under zygomatic arch

- Insertion: entire ramus of mandible

Question 5

What are the bones of the temporal fossa?

Answer 5

• Parietal
• Temporal
• Sphenoid (greater wing)
• Frontal (very small portion)

Question 6

What is the temporal fossa?

Answer 6

A depression on the temporal region of the skull, above the zygomatic arch.

Question 7

What is the most important thing to know about the infratemporal fossa?

Answer 7

It is located beneath the zygomatic arch and behind the ramus of the mandible.

Question 8

What are the main contents of the infratemporal fossa?

Answer 8

• Medial and lateral pterygoid muscles
• Maxillary artery + branches
• Mandibular divison of trigeminal n. + branches
• Chorda tympani
• Glossopharyngeal n. + branches

Question 9

What are the muscles of mastication?

Answer 9

• Medial and lateral pterygoid
• Masseter
• Temporalis

Question 10

What is the function of the lateral pterygoid muscle?

Answer 10

• Bilateral: protrude mandible

- Unilateral: produces side-to-side grinding

Question 11

What is the function of the medial pterygoid muscle?

Answer 11

• Bilateral: protrude and elevate mandible

- Unilateral: produces side-to-side movements

Question 12

What are the muscles of mastication innervated by?

Answer 12

Mandibular branch of CN V3.

Question 13

Where do the medial and lateral pterygoid muscles originate?

Answer 13

• Medial: medial surface of LATERAL pterygoid plate

- Lateral: lateral pterygoid plate (inferior head) and greater wing of sphenoid (superior head)

Question 14

What is the most important muscle in protraction of the jaw?

Answer 14

lateral pterygoid (which is assisted by medial pterygoid)

Question 15

Which muscles are involved in retraction of the jaw?

Answer 15

• Posterior fibers of temporalis

- Deep fibers of masseter

Question 16

What is the most important muscle in depression (opening) of the jaw?

Answer 16

lateral pterygoid

Question 17

What is an important contributing factor to depression of the jaw? (NOT a muscle)

Answer 17

gravity

Question 18

Which movements of the jaw does the lateral pterygoid control?

Answer 18

• Protraction

- Depression

Question 19

Which muscles are involved in elevation of the jaw?

Answer 19

• Temporalis
• Masseter
• Medial pterygoid

Question 20

Do the masseter and temporalis provide ipsilateral or contralateral movement?

Answer 20

ipsilateral

Question 21

Do the pterygoid muscles provide ipsilateral or contralateral movement?

Answer 21

contralateral

Question 22

What type of joint is the TMJ?

Answer 22

a synovial joint (more specifically, a modified hinge joint)

Question 23

Each TMJ is divided into ________ by its _______.

Answer 23

a superior and inferior compartment; articular disc

Question 24

What is the first movement of the TMJ?

Answer 24

• Lower compartment

- Hinge movement (rotation) to open jaw 1 finger breadth

Question 25

What is the second movement of the TMJ?

Answer 25

- Upper compartment | - Sliding/gliding movement along the eminence, leading to full opening and protrusion of mandible

Question 26

Why does the articular disc move with the head of the mandible?

Answer 26

To prevent bone on bone contact.

Question 27

What does the articular disc attach to?

Answer 27

Lateral pterygoid muscle and joint capsule.

Question 28

The maxillary artery is divided into 3 parts by which muscle?

Answer 28

Pterygoid muscle

Question 29

What are the main branches of the maxillary artery?

Answer 29

MIDBIPS - Middle meningeal - Inferior alveolar - Deep temporal (ant. and post.) - Buccal - Infraorbital - Posterior superior alveolar - Sphenopalatine

Question 30

Which nerve supplies the special visceral afferent (SVA) fibers for taste from the anterior 2/3rds of the tongue?

Answer 30

Chorda tympani

Question 31

What is the function of the masseter muscle?

Answer 31

close (elevate) and protrude the jaw

Question 32

What is the origin and insertion of the medial pterygoid?

Answer 32

- Origin: lateral pterygoid plate (deep) and maxilla and pyramidal plate (superficial) - Insertion: near angle of mandible

Question 33

What is the origin and insertion of the lateral pterygoid?

Answer 33

- Origin: infratemporal crest (superior) and lateral pterygoid plate (inferior) - Insertion: TMJ (superior) and mandible (inferior)

Question 34

Which nerves pass between the medial and lateral pterygoid muscles?

Answer 34

lingual and alveolar nerves

Question 35

Which pterygoid muscle opens the jaw and which closes it? What is the action they are both involved with?

Answer 35

- Lateral opens (depresses) jaw, medial closes (elevates) it | - Both protrude the jaw and grind teeth

Question 36

What are some of the bony landmarks of the infratemporal fossa?

Answer 36

- Articular tubercle of temporal bone - Mandibular fossa of temporal bone - Postglenoid tubercle of temporal bone - Condyloid process of mandible - Ramus and angle of mandible - Coronoid process and mandibular notch - Maxillary tuberosity and pyramidal process of palatine bone - Pterygomaxillary fissure - Foramen ovale and spinosum - Spine of sphenoid

Question 37

Which bony features form the TMJ?

Answer 37

- Articular tubercle of temporal bone (anterior limit) - Mandibular fossa of temporal bone (receives head of mandible to create TMJ) - Postglenoid tubercle of temporal bone (posterior limit of TMJ) - Condyloid process of mandible