DR #4 Anatomy of Scalp and face

Question 1

what are the two belly’s of occipitofrontalis?

and what connects them?

Answer 1

frontal belly
occipital belly
connected by epicranial aponeurosis

Question 2

what is the innervation to the frontal belly of occipitofrontallis?

Answer 2

temporal branch of facial nerve (CN VII)

Question 3

what is the innervation to the occipital belly of occipitofrontallis?

Answer 3

pos auricular br of facial nerve

Question 4

what is the nerve supply to orbicularris oculi

Answer 4

temporal and zygomatic branches of facial

Question 5

what is the nerve supply of the buccinator muscle

Answer 5

buccal br of facial

Question 6

name the dilator muscles of the mouth

what vein and artery lies deep to the them

Answer 6

• zygomaticus major and minor
• levator labii superioris
• risorius

facial vein and artery run deep to them

Question 7

what is the small nodular region at the angle of the mouth where some of the muscles of facial expression insert. When is this impo?

Answer 7

modiolus

- impo in prosthetic dentistry and facial surgery

Question 8

what is the nerve supply of orbicularis oris and dilators of the mouth?

Answer 8

buccal and mandibular br of facial

Question 9

where does the platysma muscle begin inferiorly and end superiorly
what is the action
what is the nerve supply

Answer 9

inf = just below and superficial to clavicle 
sup = some fibres to mandible and some to orbicularis oris 
action = pull down corner of the mouth 
NS = cervical br of facial

Question 10

where does the parotid gland lie?

Answer 10

inf to ext auditory meatus, ant to masseter and between mandible and SCM. pierces the buccinator muscle

Question 11

where does the parotid duct open?

Answer 11

opposite the 2nd upper molar tooth in the vestibule of the mouth

Question 12

what is the main action of the masseter?

Answer 12

elevation of mandible (close the mouth)

Question 13

what are the actions of temporalis?

Answer 13

pos fibres = retract mandible

mid and ant fibres = elevate the mandible

Question 14

origin and insertion of masseter?

Answer 14

origin = zygomatic arch and maxillary process of zygomatic bone 
insertion = mandibular angle + lateral surface of mandibular ramus

Question 15

identify the boundaries of the infratemporal fossa (lat, med, sup, inf, ant, pos)

Answer 15

lat = ramus of mandible 
med = lateral pterygoid plate of sphenoid 
ant = pos maxilla 
pos = tympanic plate, mastoid and styloid process 
sup = infratemporal crest of sphenoid 
inf = angle of mandible

Question 16

what are the major structures within the infratemporal fossa?

Answer 16

• medial and lateral pterygoid muscles
• mandibular br (V3) of V
• maxillary ar
• pterygoid venous plexus

Question 17

where does the lateral pterygoid muscle insert

Answer 17

condylar process of mandible along with disc and capsule of TMJ

Question 18

what is the function of the lateral pterygoid?

Answer 18

only muscle of mastication to open the mouth (depresses)

Question 19

what is the nerve supply of the muscles of mastication?

Answer 19

mandibular br of V

Question 20

what foremen within the face do the three branches of the trigeminal pass through?

Answer 20

V1 = supraorbital foramen 
V2 = infraorbital 
V3 = mental foramina

Question 21

what are the branches of the ophthalmic division of trigeminal?

Answer 21

• lacrimal
• frontal -> supraorbital, supratrochlear
• nasociliary -> long ciliary, pos ethmoidal, ant ethmoidal which goes to ext nasal
• nasociliary continues as infratrochlear

Question 22

what are the branches of the maxillary division?

Answer 22

infraorbital, zygomaticofacial, zygomaticotemporal

Question 23

what are the branches of the mandibular division?

Answer 23

auriculotemporal, buccal, mental, lingual, inf alveolar

Question 24

where does the facial nerve emerge from the skull?

Answer 24

stylomastoid foramen

Question 25

what are the 5 main terminal branches of the facial nerve

and what is their function?

Answer 25

• temporal
• zygomatic
• buccal
• marginal mandibular
• cervical

motor supply of muscles of facial expression

Question 26

differentiate between an UMN and LMN lesion of the facial nerve

Answer 26

UMN L (stroke) = contralateral lower face paralysis (upper half is spared)

LMN L (bell’s palsy) = ipsilateral whole face paralysis (all muscles of facial expression)

Question 27

which artery supplies lateral face and scalp?

and what is it a branch of?

Answer 27

transverse facial ar branch of superficial temporal ar

Question 28

which artery supplies the anteromedial aspect of the scalp?

Answer 28

ophthalmic ar

Question 29

what are the layers of the scalp?

Answer 29

S - skin 
C - connective tissue 
A - aponeurosis 
L - loose connective tissue 
P - pericranium

Question 30

which artery supplies the pos aspect of the scalp

Answer 30

occipital ar

Question 31

describe the boundaries of the “danger triangle”

Answer 31

base = oral fissure 
apex = masion 
laterally = all of the nose