Unit 12: Deep Face and Infratemporal Fossa

Question 1

Name the borders of the temporal fossa. Describe them.
- Posterior/Superior Boundary
- Inferior Boundary
- Anterior Boundary
- Roof (Lateral Wall)
- Floor (Medial Wall)

Answer 1

1) Posterior/Superior Boundary = Temporal Lines
2) Inferior Boundary = Zygomatic arch & Infratemporal crest of sphenoid bones
3) Anterior Boundary = Frontal & Zygomatic bones
4) Roof (Lateral Wall) = Temporal Fascia
5) Floor (Medial Wall) = Frontal, parietal, temporal, & greater wing of sphenoid bones

Question 2

Name the contents of the temporal fossa

Answer 2

1) Temporalis muscle
2) Neurovascular = Deep temporal nerves, arteries, and veins

Question 3

Name and describe the borders of the infratemporal fossa
- Superior Boundary/Roof
- Inferior Boundary/Floor
- Posterior Boundary
- Anterior Boundary
- Lateral Boundary
- Medial boundary

Answer 3

1) Superior Boundary/Roof = Infratemporal surface of the greater wing of sphenoid bones
2) Inferior Boundary/Floor = Level with the angle of the mandible
3) Posterior Boundary = Tympanic plate, Mastoid and styloid processes
4) Anterior Boundary = Infratemporal surface of the maxilla
5) Lateral Boundary = Mandibular ramus & coronoid process
6) Medial Boundary = Lateral pterygoid plate, tensor veli palatini, levator veli palatini

Question 4

Name the contents of the infratemporal fossa

Answer 4

1) Medial & Lateral pterygoid muscles
2) Maxillary artery & branches
3) Pterygoid venous plexus
4) CN V3 & Branches
5) Chorda Tympani Nerve
6) Otic Ganglion

Question 5

Describe the infratemporal fossa communications

Answer 5

1) Temporal Fossa = Through a gap bounded by the zygomatic arch
2) Orbit = through the inferior orbital fissure
3) Pterygopalatine Fossa = Through the pterygomaxillary fissure
4) Middle Cranial Fossa = Through the foramen ovale and foramen spinosum
5) Inferior = The neck

Question 6

Name the temporomandibular joint (TMJ) bones

Answer 6

1) Head of the mandible
2) Mandibular fossa of temporal bone
3) Articular tubercle of temporal bone

Question 7

What is the structure of TMJ?

Answer 7

Hinge-like synovial joint

Question 8

What are the movements of TMJ?

Answer 8

1) Elevation & Depression
2) Protraction & Retraction
3) Side-to-Side

Question 9

Describe the TMJ Articular Disc

Answer 9

• Fibrocartilaginous disc that divides/separates the synovial joint cavity into superior and inferior compartments
  
  • Articular disc slides forward into the superior compartment
  • Rotation of the mandible (opening of the mouth) occurs in the inferior compartment

Question 10

What are the ligaments of the TMJ?

Answer 10

1) Joint Capsule
2) Lateral Ligaments
3) Sphenomandibular Ligament
4) Stylomandibular Ligament

Question 11

Joint Capsule of TMJ

Answer 11

Wraps the TMJ, attaching to zygomatic arch, articular cartilage of mandibular fossa of temporal bone, and neck of mandible

Question 12

Lateral ligaments of TMJ

Answer 12

A thickened area of the joint capsule, helping to minimize posterior dislocations of the joint

Question 13

Sphenomandibular Ligament of TMJ

Answer 13

From the spine of the sphenoid to the lingula of the mandible and is called the “swinging hinge” of the mandible

Question 14

Stylomandibular Ligament of TMJ

Answer 14

From styloid process of temporal bone to the inside angle of mandible

Question 15

True/False = Thickened portion of parotid gland CT capsule provides some support of the mandible

Answer 15

True

Question 16

What two nerves innervate the TMJ?

Answer 16

• Sensory innervation = Auriculotemporal nerve and masseteric nerve

Question 17

What the superficial and deep muscles of mastication?

Answer 17

1) Superficial
- Temporalis Muscle
- Masseter Muscle
2) Deep
- Medial Pterygoid Muscle
- Lateral Pterygoid Muscle

Question 18

Temporalis Muscle

Answer 18

• Origin = Temporal Fossa and Fascia
• Insertion = Coronoid process and and anterior border of mandibular ramus
• Action = Elevate and retract the mandible
• Innervation = CN V3 mandibular division of trigeminal nerve

Question 19

Masseter Muscle

Answer 19

• Origin = Inferior and medial surfaces of zygomatic arch
• Insertion = Lateral surface of the angle and ramus of mandible
• Action = Elevates mandible (deep fibers also retract)
• Innervation = CN V3 mandibular division of trigeminal nerve

Question 20

Medial Pterygoid Muscle

Answer 20

• Origin = Medial surface of the lateral pterygoid muscle & maxillary tuberosity
• Insertion = Medial surface of the angle and ramus of mandible
• Action(s) = Elevates mandible and small side-to-side movements
• Innervation = CN V3 mandibular division of Trigeminal nerve

Question 21

Lateral Pterygoid Muscle

Answer 21

• Origin
  
  • Superior Head = Infratemporal surface of the greater wing of sphenoid bones
  • Inferior Head = Lateral surface of the lateral pterygoid plate
• Insertion
  
  • Superior Head = TMJ Capsule
  • Inferior Head = Condylar process of mandible
• Action
  
  • Protrudes mandible
  • Initiates depression of mandible
  • Side to Side movements
• Innervation = CN V3 mandibular division of trigeminal nerve

Question 22

Describe the maxillary artery

Answer 22

• Main artery of the infratemporal fossa
• Branch of external carotid artery that terminates near the neck of the mandible

Question 23

Describe the maxillary artery - part 1

Answer 23

Lateral to lateral pterygoid muscle and medial to the neck of the mandible

Question 24

What are the arteries in maxillary artery - part 1

Answer 24

1) Deep Auricular Artery
2) Anterior Tympanic Artery
3) Middle Meningeal Artery
4) Accessory Meningeal Artery
5) Inferior Alveolar Artery

Question 25

What are the branches of maxillary artery - part 1? Describe them.

Answer 25

1) Middle Meningeal Artery = Passes superiorly between the two roots of auriculotemporal nerve - Moves through foramen spinosum - Main bloody supply to dura mater 2) Accessory Middle Meningeal Artery = Passes superiorly through foramen ovale - Supplies dura mater and trigeminal ganglion 3) Inferior Alveolar Artery = Travels with inferior alveolar nerve - Enters mandible through mandibular foramen to supply lower/mandibular teeth - Leaves mandible through mental foramen (as mental artery) to supply skin over the mandible

Question 26

Describe the maxillary artery - part 2

Answer 26

* Deep to lateral pterygoid muscle - Each muscle of mastication takes a branch plus the cheek 1) Masseteric Branch = Moves through mandibular notch to masseter muscle 2) Deep Temporal Branches = Moves superiorly to deep side of temporalis muscle 3) Pterygoid Branches = To medial and lateral pterygoid muscles 4) Buccal Artery = To buccinator muscle and nearby gums/cheeks

Question 27

Describe the maxillary artery - part 3

Answer 27

* Medial to lateral pterygoid muscle - Enters pterygopalatine fossa - Supplies lower nasal cavity, palate and upper teeth, maxillary sinus, and superficial midface

Question 28

What is the pterygoid venous plexus?

Answer 28

Network of veins accompanying maxillary artery

Question 29

Describe the pterygoid venous plexus communications?

Answer 29

* Communicates with: 1) Cavernous Sinus (via emissary veins) 2) Inferior Ophthalmic Veins (via inferior orbital fissure). 3) Facial Vein (via deep facial vein)

Question 30

What vein the pterygoid venous plexus terminate as? Where does it flow into?

Answer 30

Pterygoid venous plexus terminates maxillary vein that flows into the retromandibular vein

Question 31

CN V3 moves from the ________, through ___________ into the __________

Answer 31

1) middle cranial fossa 2) foramen ovale 3) infratemporal fossa

Question 32

What are the 3 portions of CN V3?

Answer 32

1) Main trunk 2) Anterior division 3) Posterior division

Question 33

Name the contents of the main trunk of CN V3. Describe them.

Answer 33

1) Meningeal branch - Sensory to meninges - Travels with middle meningeal artery 2) Nerve to medial pterygoid (and nerves to TVP & TTymp) - Motor to medial pterygoid (and tensor veli palatini, tensor tympani muscle)

Question 34

Name the contents of the anterior division of CN V3

Answer 34

1) Masseteric nerve - Motor to masseter muscle - Sensory to TMJ 2) Deep temporal nerve = Motor to temporalis muscle 3) Nerve to lateral pterygoid = Motor lateral pterygoid muscle 4) Buccal Nerve = Sensory to skin of cheek and nearby gums

Question 35

Name the contents of the posterior division of CN V3

Answer 35

1) Auriculotemporal nerve = Sensory to TMJ, skin near the ear carries postganglionic parasympathetic fibers from otic ganglion to the parotid gland 2) Lingual Nerve = Sensory to anterior 2/3 of tongue carries chorda tympani nerve to teh submandibular gg. and glands 3) Inferior alveolar nerve = Sensory to mandible teeth & skin enters mandibular foramen after giving off nerve to mylohyoid (which itself is all motor)

Question 36

Otic Ganglion

Answer 36

Parasympathetic ganglion containing postganglionic neurons which receive preganglionic fibers form the glossopharyngeal nerve (CN IX) via the lesser petrosal nerve

Question 37

What is the otic ganglion physically supported by?

Answer 37

Physically supported by the mandibular nerve as it emerges through foramen ovale

Question 38

Chorda Tympani Nerve

Answer 38

* A branch of the facial nerve (CN VII) * Carries preganglionic parasympathetic fibers destined for the submandibular gland * Carries taste fibers from taste buds in the anterior 2/3 of the tongue * Leaves skull through the petrotympanic fissure * Travels with the lingual nerve of CN V3

Question 39

The infratemporal fossa communicates anteriorly with the orbit through what structure?

Answer 39

Inferior orbital fissure

Question 40

Where is the inferior alveolar nerve mixed vs purely sensory?

Answer 40

1) Mixed = Before giving off to nerve to mylohyoid 2) Sensory = After gives off nerve to mylohyoid (within mandible and as mental nerve)

Question 41

What nerves provide sensory innervation to the temporomandibular joint?

Answer 41

1) Auriculotemporal nerve 2) Nerve to masseter

Question 42

Through which foramen does the nerve that innervates the muscles of mastication pass?

Answer 42

Foramen ovale (the mandibular branch of the trigeminal nerve carries motor fibers that innervate the muscles of mastication)

Question 43

What type of fibers does the chorda tympani bring to the lingual nerve?

Answer 43

1) Special sense - Taste to anterior 2/3 of tongue 2) Preganglionic Parasympathetics - To submandibular ganglion

Question 44

What is unique about the action of the lateral pterygoid muscle?

Answer 44

It is the only muscle of mastication that aids in opening the mouth

Question 45

What is the nerve that branches from the inferior alveolar nerve before it enters the mandibular foramen, and which muscles does it innervate?

Answer 45

1) Nerve to mylohyoid 2) Innervates mylohyoid and anterior belly of digastric muscle

Question 46

How does the pterygoid plexus of veins communicate with the facial vein and into which vein does the pterygoid plexus drain into?

Answer 46

1) Deep facial vein 2) Empties into maxillary vein

Question 47

Is the buccal branch of the mandibular division of the trigeminal nerve sensory, motor, or both?

Answer 47

Sensory

Question 48

What is the relationship between the middle meningeal artery and the auriculotemporal nerve?

Answer 48

The auriculotemporal nerve arises by two roots separated by the middle meningeal artery