Deep Face and Infratemporal Fossa

Question 1

Boundaries of the infratemporal fossa- lateral, anterior, medial, posterior, roof, inferior

Answer 1

Lateral- ramus of mandible
Anterior- maxilla
Medial- lateral pterygoid plate
Roof- sphenoid greater wing
Posterior- tympanic plate and mastoid and styloid process
Inferior- angle of mandible

Question 2

Muscles and arteries/veins in infratemporal fossa

Answer 2

Inferior portion of temporalis muscle
Lateral and medial pterygoid muscles
Maxillary artery
Pterygoid venous plexus

Question 3

Nerves in infratemporal fossa

Answer 3

Inferior alveolar V3
Lingual V3
Buccal V3
Chorda tympani - CN VII
Otic ganglion

Question 4

Deep auricular artery

Answer 4

Branch of mandibular part of maxillary artery

Supplies external acoustic meatus, external TM and TMJ

Question 5

Anterior tympanic artery

Answer 5

Branch of mandibular part of maxillary artery

Supplies internal TM

Question 6

Inferior alveolar artery

Answer 6

Branch of mandibular maxillary
Enters mandibular foramen and supplies mandible, mandibular teeth, chin and mylohyoid muscle
gives off mylohyoid artery, later becomes mental artery

Question 7

Middle meningeal artery

Answer 7

Branch of mandibular maxillary
Enters cranium via foramen spinosum and supplies dura mater of the lateral wall, trigeminal ganglion, facial nerve and geniculate ganglion, tympanic cavity and tensor tympani

Question 8

Accessory meningeal artery

Answer 8

Branch of mandibular maxillary
Enters cranium via foramen ovale and supplies extracranial muscles of infratemporal fossa, otic ganglia and sphenoid bone

Question 9

Maxillary artery in relation to lateral pterygoid

Answer 9

Can run lateral or medial to the lateral pterygoid muscle

Question 10

Maxillary artery in relation to buccal, lingual, mandibular and inferior alveolar nerves

Answer 10

Runs lateral to inferior alveolar and medial to buccal nerve
Can run lateral or medial to lingual nerve
Runs medial to the mandibular nerve

Question 11

Four muscles of mastication

Answer 11

Temporalis
Masseter
Lateral pterygoid
Medial pterygoid

Question 12

Masseter muscle OINA

Answer 12

O- zygomatic bone and arch
I- mandibular angle/ramus
N- masseteric nerve- anterior division of CN V3
A- elevates mandible, assists in protraction, retraction and side to side motion

Question 13

Temporalis OINA

Answer 13

O- temporal fascia and fossa
I- Coronoid process of mandible
N- deep temporal nerve (anterior division of CN V3)
A- vertical fibers- elevate mandible
horizontal fibers- retract mandible
unilateral- lateral movement of mandible

Question 14

Lateral pterygoid OINA

Answer 14

O- greater wing of sphenoid bone, lateral pterygoid plate
I- mandible and TMJ
N- Lateral pterygoid nerve (ant division of CN V3)
A- bilateral- protrudes mandible and opens mouth
unilateral- alternating actions, along with ipsilateral pterygoid, result in side to side movements necessary for grinding

Question 15

Medial pterygoid OINA

Answer 15

O- maxilla and palatine bone, lateral pterygoid plate
I- pterygoid rugosity
N- medial pterygoid nerve (ant division of CN V3)
A- bilateral- elevation of mandible, also acts with lateral pterygoid to assist in protrusion
unilateral- acts with ipsilateral pterygoid to protrude mandible and produce medial movement toward opposite side. Alternating actions b/w right and left sides results in side to side chewing movement

Question 16

Digastric muscle OINA

Answer 16

O- digastric fossa anteriorly, medial to mastoid posterior
I- body of hyoid bone via intermediate tendon
A- elevates hyoid during swallowing, assists in opening mandible
N- anterior belly- nerve to mylohyoid (from mandibular nerve of CN V)
posterior belly- facial nerve

Question 17

Geniohyoid OINA

Answer 17

O- inferior mental spine of mandible
I- body of hyoid
A- draws hyoid forward during swallowing, assist in opening mandible
N- ventral ramus of C1

Question 18

Mylohyoid OINA

Answer 18

O- mylohyoid line of mandible
I- body of hyoid bone by median tendon
A- tightens and elevates oral floor, draws hyoid forward during swallow, assists in opening mandible and moving it side to side
N- mylohyoid nerve from mandibular branch of CN V

Question 19

Stylohyoid OINA

Answer 19

O- styloid process of temporal bone
I- body of the hyoid bone by split tendon
A- elevates hyoid bone during swallow, assists in opening mandible
I- facial nerve

Question 20

Sternohyoid action innervation

Answer 20

Depresses/fixes hyoid bone
Depresses larynx and hyoid bone for phonating and the terminal phase of swallowing
N- ansa cervicalis of the cervical plexus C1-C3 and C4

Question 21

Sternothyroid action innervation

Answer 21

A- draws the larynx and hyoid bone downward (fixes)
depresses the larynx and hyoid bone for phonating and terminal phase of swallowing
N- ansa cervicalis of the cervical plexus C1-3 and C4

Question 22

Thyrohyoid action innervation

Answer 22

A- depresses and fixes hyoid, raises larynx during swallowing
N- ventral ramus of C1 and C4

Question 23

Omohyoid OINA

Answer 23

O- superior border of scapula
I- body of hyoid
A- Depresses/fixes hyoid, draws larynx and hyoid bone downward for phonation and terminal phase of swallowing. Tenses the cervical fascia with its intermediate tendon and maintains patency of internal jugular vein
N- ansa cervicalis of cervical plexus C1-3 and C4

Question 24

Elevation of mandible is primarily carried out by

Answer 24

Temporalis, masseter, medial pterygoids

Question 25

Depression of mandible is primarily carried out by

Answer 25

Lateral pterygoids, suprahyoid and infrahyoid muscles

Question 26

Protrusion of mandible primarily carried out by

Answer 26

Lateral pterygoids, masseter, medial pterygoids

Question 27

Retrusion of mandible primarily carried out by

Answer 27

Temporalis, masseter

Question 28

Lateral movements of mandible primarily carried out by

Answer 28

Ipsilateral temporalis and masseter + contralateral pterygoids

Question 29

Ligaments of TMJ and their function

Answer 29

Lateral temporomandibular ligament
Stylomandibular ligament
Sphenomandibular
Latter 2 ligaments limit inferior excursion at TMJ

Question 30

TMJ joint is innervated by

Answer 30

Mandibular branch of trigeminal- branches into auriculotemporal nerve, posterior deep temporal nerve and masseteric nerve