Temporal and Infratemporal Fossae

Question 1

Coronoid process

Answer 1

the site of insertion for the temporalis muscle

Question 2

Mandibular foramen

Answer 2

Where Inferior Alveolar nerve and artery pass into the mandible

Question 3

Mental foramen

Answer 3

The Inferior Alveolar nerve and artery exit the bone through the mental foramen as the Mental nerve and artery

Question 4

Muscles of mastication

Answer 4

1) Temporalis,
2) Masseter,
3) Medial pterygoid
4) Lateral pterygoid

All are inverted by the Mandibular nerve (CN V3).

Question 5

Elevation or closing the jaw

Answer 5

1) Temporalis,
2) Masseter,
3) Medial pterygoid

Question 6

Depression or opening the jaw

Answer 6

1) gravity,
2) mylohyoid
3) digastric
4) geniohyoid

Question 7

Protrusion or Anterior movement of the jaw

Answer 7

Lateral pterygoid (assisted somewhat by Medial pterygoid)

Question 8

Restriction orPosterior movement of the jaw

Answer 8

The posterior, horizontal fibers of temporalis (assisted by digastric and geniohyoid)

Question 9

Sliding and rotatory (grinding) movement of the jaw

Answer 9

1) Medial pterygoid

2) Lateral pterygoid

Question 10

Temporalis Muscle

Answer 10

• Origin: Floor of the temporal fossa which includes
portions of four bones of the cranium (temporal, parietal, frontal and sphenoid) which come together at the pterion.
• Insertion: The muscle passes medial (deep) to the zygomatic arch to insert on the coronoid process of
the mandible and is covered on its external surface by the tough temporalis fascia from which it also
originates.
• Innervation: Mandibular nerve (CN V3)

Question 11

Temporalis fascia

Answer 11

• Origin: Superior temporal line
• Insertion: Inserts on and supports the zygomatic
arch, resisting the inferior pull of the masseter muscle

Question 12

Masseter muscle

Answer 12

• Origin: Zygomatic arch
• Insertion: lateral aspect of the ramus and angle of the mandible.
• Innervation: Mandibular nerve (CN V3)

Question 13

Medial pterygoid

Answer 13

• Origin: Medial surface of the lateral pterygoid plate
• Insertion: Medial aspect of the ramus and angle of the mandible inferior to the mandibular foramen
• Innervation: Mandibular nerve (CN V3)

Question 14

Lateral pterygoid

Answer 14

• Origin: Lateral surface of the lateral pterygoid plate
• Insertion: Capsule and articular disc of the Tempporomandibular joint (TMJ) and the neck of the mandible (pterygoid fovea)
• Innervation: Mandibular nerve (CN V3)

If one lateral pterygoid muscle is paralyzed, the contraction of the contralateral muscle will cause the jaw to protrude toward the side of the paralyzed
muscle.

Question 15

Mandibular notch

Answer 15

Mandibular artery and nerve passes laterally through the mandibular notch

Question 16

Buccinator muscle

Answer 16

Innervated by CN VII; Maxillary nerve

Question 17

Parotid Duct

Answer 17

Pierces through the buccinator muscle to drain the oval cavity opposite the second maxillary molar tooth

Question 18

Temporal Fossa

Answer 18

The temporal fossa is a shallow depression superior
to the zygomatic arch and contains the temporalis
muscle and its blood and nerve supply as well as the zygomaticotemporal branch of the maxillary nerve (V2).

Question 19

Sphenomandibular ligament

Answer 19

It runs from the spine of the sphenoid to the lingula on the mandibular ramus, helps maintain the mandibular condyle in position and becomes fully taut when the jaw is half open.

Question 20

Temporomandibular joint (TMJ)

Answer 20

The TMJ is a very complex synovial joint involving
the condyle of the mandible and both the mandibular fossa and articular tubercle of the temporal bone, as well as an articular disc made of
fibrous connective tissue with some features similar
to cartilage

Question 21

Infratemporal fossa

Answer 21

It’s an extracranial area located just inferior to the

temporal fossa and the zygomatic arch.

Question 22

Structures in the Infratemporal fossa

Answer 22

1) The two pterygoid muscles
2) Maxillary artery
3) Mandibular nerve (V3)
4) Chorda tympani nerve
5) Pterygoid venous plexus
6) The parasympathetic otic ganglion

Question 23

Major branches of the Maxillary artery

Answer 23

1) Middle meningeal artery

2) Inferior alveolar artery

Question 24

Middle meningeal artery

Answer 24

Pathway:Passes between the two roots of the auriculotemporal nerve (a branch of V3) and ascends to and through the foramen spinosum to enter the cranial cavity
Supplies: Major supplier of the dura mater.

Question 25

Inferior alveolar artery

Answer 25

Pathway: travels inferiorly to enter the mandibular foramen Supplies: supplies the mandibular teeth and soft tissues It exits the mandible anteriorly through the mental foramen as the mental artery.

Question 26

Lesser branches of the Maxillary artery | First Portion

Answer 26

1) the deep auricular, 2) anterior tympanic 3) accessory meningeal They contribute blood to the external acoustic meatus, middle ear and dura mater

Question 27

Lesser branches of the Maxillary artery | Second Portion

Answer 27

1) Deep temporal - temporalis 2) Masseteric artery - masseter 3) Pterygoid artery - pterygoid 4) Buccal artery - buccinator They supply muscles of the temporal and infratemporal fossa

Question 28

Mandibular Nerve

Answer 28

It enters the infratemporal fossa through the foramen ovale and innervates deeper structures of the face and oral cavity. It is the only branch of the trigeminal nerve with somatic efferent motor components to the 4 muscles of mastication and 4 other muscles It also has 5 sensory nerve branches

Question 29

Nerve branches of Mandibular Nerve

Answer 29

1) Inferior alveolar 2) Lingual 3) Auricotemporal 4) Meningeal 5) Buccal

Question 30

Inferior alveolar

Answer 30

It enters the mandibular foramen after giving off the motor nerve to the mylohyoid and anterior belly of the digastric muscles; sensory to the mandibular teeth and, as its terminal mental nerve, the lower lip and chin.

Question 31

Lingual

Answer 31

It provides general sensation to the anterior ⅔ of the tongue and floor of mouth. (Accompanied for part of its course by the chorda tympani nerve.)

Question 32

Auricotemporal

Answer 32

It travels beside the parotid gland and ascends next to the superficial temporal artery to the temporal region; sensory to temporal skin, ear structures, TMJ and parotid gland. Also carries secretomotor parasympathetic postganglionic fibers from the otic ganglion to the parotid.

Question 33

Meningeal

Answer 33

It travels with the middle meningeal artery through the foramen spinosum to supply the dura mater of the middle cranial fossa mainly.

Question 34

Buccal

Answer 34

It provides sensory to the skin, oral mucosa and gingiva in the cheek region. (The buccinator muscle itself is innervated by the facial nerve.)

Question 35

Muscles Innervated by the Mandibular Nerve

Answer 35

It innervates the four muscles of mastication and the following muscles: 1) Anterior belly of the digastric 2) Mylohyoid 3) Tensor veli palatini (in soft palate) 4) Tensor tympani (middle ear)

Question 36

Chorda Tympani

Answer 36

Preganglionic parasympathetic fibers exit the brainstem with the facial nerve. In the facial canal, it branches as the Chorda Tympani. It hitchikes a ride with the Lingual nerve ans synampses in the Submandibular ganglion. Postganglionic secretomotor fibers travel to the submandibular and sublingual salivary glands as well as the multiple minor microscopic salivary glands in the inferior oral cavity.

Question 37

Taste Fibers

Answer 37

Afferent special sense taste fibers from the anterior ⅔ of the tongue, originally traveling in the lingual nerve, join the chorda tympani and travel posteriorly to join CN VII back to the brainstem. These taste fibers have their pseudo-­‐unipolar nerve cell bodies in the geniculate ganglion of CN VII.

Question 38

Parasympathetic to Parotid

Answer 38

Other preganglionic parasympathetic fibers leave the glossopharyngeal nerve (CN IX) inferior to the jugular foramen in the tympanic nerve. They enter the middle ear and ascend on the promontory in the tympanic plexus and exit it as the lesser petrosal nerve. After re-­‐entering the cranial cavity they travel down the petrous ridge and exit through the foramen ovale to synapse in the ottic ganglion. Postganglionic parasympathetc secretomotor fibers “hitch-­‐hike a ride” on the auriculotemporal nerve to the parotid gland.

Question 39

Pterygoid Venous Plexus

Answer 39

The pterygoid venous plexus also has direct valveless drainage into the cavernous sinus, so infections could spread there and lead to a cavernous sinus thrombosis, a potentially fatal situation.