clinical anatomy of the face Flashcards
what does pneumatised mean?
air within the bones
what bones are pneumatised?
what form are these in?
the frontal, temporal, sphenoid, ethmoid and maxillary bones
what are the 2 parts of the skeleton of the head?
neurocranium - bony covering of brain and meninges
viscerocranium - facial skeleton
what makes up the neurocranium?
- roof called calvaria
- floor called cranial base (brain sits on)
- 8 bones
what 8 bones make up the neurocranium?
frontal
ethmoid
sphenoid
occipital
temporal X2
parietal X2
what makes up the viscerocranium?
14 bones
what bones are in the form of paranasal sinuses?
frontal, sphenoid, ethmoid and maxillary bones
what is the external auditory meatus?
ear canal
what blood vessels lie under the pterion?
middle meningeal blood vessels
what is the weakest point of the skull?
pterion
trauma to the pterion may cause the middle meningeal blood vessels to rupture. what would this be called?
extra- dural haemorrhage
how much of non verbal communication does our face provide?
80 to 90%
what does our facial identity depend on?
underlying skeleton as well as growth of the skeleton
what are the nerves that come off of the spinal cord?
spinal nerves
name the 5 groups of spinal nerves and how many of each?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
what are the spinal nerves that come off of the neck called?
8 cervical
what spinal nerves are below the cervical nerves to the lower chest called?
12 thoracic
what spinal nerves are between the lower part of the ribcage and the upper pelvis?
5 lumbar
what are the spinal nerves that are near our bum?
5 sacral
what is the last spinal nerve?
1 coccygeal
how many pairs of spinal nerves are there all together?
31
what nerves come off of the brain and brainstem?
12 paired cranial nerves
what are the 3 branches of the trigeminal nerve?
ophthalmic, maxillary and mandibular divisions
what does the trigeminal nerve supply?
sensory innervation to the face
motor innervation of muscles of mastication
what does the facial nerve supply?
muscles of facial expression (branchial motor fibres/special visceral efferent)
special sensory fibres (special visceral afferent; taste),
general sensory fibres (general somatic afferent; ear)
parasympathetic fibres (general visceral efferent – innervating the sublingual and submandibular salivary glands)
what area is supplied by the ophthalmic nerve?
Forehead and scalp
Frontal and ethmoidal sinus
Upper eyelid and its conjunctiva
Cornea (see clinical relevance)
Dorsum of the nose
what area is supplied by the maxillary nerve?
Lower eyelid and its conjunctiva
Cheeks and maxillary sinus
Nasal cavity and lateral nose
Upper lip
Upper molar, incisor and canine teeth and the associated gingiva
Superior palate
what area is supplied by the mandibular nerve sensory supply?
Mucous membranes and floor of the oral cavity
External ear
Lower lip
Chin
Anterior 2/3 of the tongue (only general sensation; special taste sensation supplied by the chorda tympani, a branch of the facial nerve)
Lower molar, incisor and canine teeth and the associated gingiva
what is the mandibular nerve motor supply?
Muscles of mastication; medial pterygoid, lateral pterygoid, masseter, temporalis
Anterior belly of the digastric muscle and the mylohyoid muscle (these are suprahyoid muscles)
Tensor veli palatini
Tensor tympani”
where is type 1 and type 2 herpes simplex most common?
1 - mouth
2 - genitalia
what does varicella zoster virus result in?
infection results in chickenpox and can cause lung and airway disease like bronchitis or pneumonia.
what happens when the varicella zoster virus resolves?
When it resolves the virus lays dormant in the ganglia (collection of cell bodies)
can the varicella zoster virus reactivate?
reactivate in 10-20% of people resulting in shingles or herpes zoster
can the varicella zoster virus reactivate?
reactivate in 10-20% of people resulting in shingles or herpes zoster
what are the 3 branches of the trigeminal nerve?
5a = ophthalmic nerve
5b = maxillary nerve
5c = mandibular nerve
what are the sensory and motor parts of the trigeminal nerve?
sensory = opthalmic nerve, maxillary nerve, mandibular nerve
motor = muscles of mastication, mandibular nerve aswel
what does the masseter do?
Elevates the mandible and closes the mouth
what does the temporals do?
Elevates the mandible and closes the mouth, retraction of the mandible
what does the lateral pterygoid do?
Both left and right acting at the same time will result in protraction of the mandible. When one acts on its own it results in deviation of the mandible to the opposite side.
what does the medial pterygoid do?
Elevation of the mandible, closure of the mouth
where does the masseter attach?
from the zygomatic arch to the mandible
where does the temporals attach?
onto the frontal and parietal bones to the coronoid process of the mandible
how many muscles are in the face?
43
how are the muscles of the face arranged?
around the orifices
attached to bone or fascia then the skin
what nerve supplies the muscles of the face?
facial nerve
CN 7
what are the muscles of the mouth, lips and cheeks important for?
clear speech
swallowing
eating
drinking
what do evertors do in the upper and lower lip?
allow us to pout
what doe elevators and depressors do to the upper and lower lip?
like them up and down while smiling for example
what do retractors do to the upper and lower lip?
pull them back
where does the obicularis oris originate from and where does it insert?
Originates from the maxilla and cheek muscles inserting into the lips – skin and mucous membrane of the lips.
what is the obicularis oris involved in?
pursing of the lips – think of the selfie pout!!!
what supplies the obicularis oris?
buccal branch of the facial nerve
where is the obicularis oris?
round the mouth
where does the buccinator originate from and where does it extend to?
Originates from the maxilla and the mandible and extends down to blend with the orbicularis oris and the skin of the lips.
what does the buccinator do?
Pulls cheeks inwards resulting in pushing food and fluid into the centre of the oral cavity.
what supplies the buccinator?
buccal branch of facial nerve
what are the 2 parts of the obicularis oculi?
orbital part
palpebral part
which part of the obicularis oculi circles the eye?
orbital part
what does the orbital part of the obicularis oculi do?
strong closure of the eyes
what is the thicker part of the obicularis oculi?
orbital part
what does the palpebral part of the obicularis oculi do?
soft closure of eyes including blinking
where are the auricular muscles?
around the ear
what do the auricular muscles do?
move the ears
why the the auricular muscles so small?
as few people can move their ears voluntarily
what are the 3 auricular muscles?
posterior
anterior
superior
where does the parotid duct pass and where does it enter the oral cavity?
from the anterior aspect and enters the oral cavity opposite the upper second molar
what 3 major structures pass through the parotid gland?
- external carotid artery (+ terminal branches - maxillary and superficial temporal arteries)
- retromandibular vein (superficial, temporal and maxillary veins unite)
- facial nerve
what encloses the parotid gland?
tight investing fascia
what causes mumps?
paramyxovirus
what is the main visible symptom of mumps?
swelling of the parotid gland, lymph nodes (including those in the parotid gland)
what problems does swelling of the parotid gland cause?
deafness, infertility and meningitis
what is facial palsy?
weakness and loss of function of the muscles of facial expression
what is a parotidectomy?
surgical removal of the parotid gland
what happens to the face in bells palsy?
facial paralysis of one side of the face
when can bells palsy be diagnosed?
if there is no other specific cause that can be identified
when can bells palsy be diagnosed?
if there is no other specific cause that can be identified
why is the treatment of bells palsy controversial?
- due to herpes simplex/zoster
- linked to HIV and other viruses
where does the facial nerve leave the skull?
through the stylomastoid foramen
what are the 2 treatments for bells palsy?
prednisolone - steroid helps with inflammation
acyclovir (orally) - helps with viral infection
what percent of head and neck tumours are in salivary glands?
what % of this is in the parotid gland?
3%
75-85%
what percent of salivary gland tumours are benign?
70-80%
what does the temporal branch of the facial nerve do?
Innervates the frontalis, orbicularis oculi and corrugator supercilii
what does the zygomatic branch of the facial nerve do?
innervates the orbiculares oculi
what does the buccal branch of the facial nerve do?
Innervates the orbicularis oris, buccinator and zygomaticus muscles
what does the marginal mandibular branch of the facial nerve do?
innervates the mentalis muscle
what does the cervcial branch of the facial nerve do?
innervates the platysma
what is an anterograde parotidectomy?
involves identifying main trunk of facial nerve then trace out to the smaller branches as you go
what is a modified blair incision?
pre-auricular incision (in front of ear), to below the ear, back up over the mastoid process and into the skin crease of the neck
what is a retrograde parotidectomy?
involves identifying a smaller branch of the facial nerve and tracing it back to the parotid gland
what is the most common method of parotidectomy?
anterograde as its easier to find main bit of nerve
what is a nerve stimulator?
buzz any area which looks like the facial nerve and this will result in the electrodes picking up the impulse
what are surgical drapes used for?
to allow only the areas being operated on to be visible
what happens if you image the branch of the facial nerve that passes the angle of the mandible?
loss of function of muscles at lower lip
what is the Sternocleidomastoid?
muscle that moves the neck to the opposite side when there is ipsilateral contraction and when both contract there is flexion of the neck
what nerve could be used in a nerve graft if the parotidectomy is complicated and the facial nerve is damaged?
great auricular nerve C2/3
in a parotidectomy why do we move the parotid gland out the way?
to get deep into the main part of the facial nerve
what is facial reanimation?
bringing the face back to left after any kind of nerve damage
what does reanimation treatment of the face depend on?
level of injury and paralysis
duration of the paralysis (greater than 12 months the treatment may not be valid)
what are the 2 ways to describe facial reanimation?
dynamic - full movement of the face
static - make face symmetrical (cosmetic rather than function)
when would facial reanimation be considered dynamic?
immediate/ early reconstruction - right away
intermediate reconstruction - after recovery time
when would facial reanimation be considered static?
> 12 months after injury
or after complications
when is a hypoglossal facial anastomosis used?
for patients with intermediate duration length facial paralysis
what is hypoglossal - facial anastomosis?
joining CN12 to CN7 for facial reanimation
what type of joining is most commonly used in hypoglossal - facial anastomosis?
side to end joining of the nerves
what nerves innervates the tongue?
what nerve innervates the facial muscles?
hypoglossal nerve CN12
facial nerve CN7
what is the main complication of a hypoglossal - facial anastomosis?
how can this be revolved?
due to the hypoglossal nerve be used to innervate the tongue and now the face aswel….
when the patient spoke or swallowed/ate there was twitching of the face at the same time
- physiotherapy and botox
what is the fascia lata (iliotibial tract) used for in facial reanimation?
taken out of thigh and placed in and around the zygomatic bone and anchored to the modiolus (corner of mouth) to prevent the jokers smile
what is the fascia lata (iliotibial tract)?
fibrous avascular band running down the lateral aspect of the thigh with a minor role in hip movement and knee stabilization
where is the fascia lata inserted in static facial reanimation?
through the hairline
what is the original incision would be made to retrieve the facia lata?
lazy s shape along the upper thigh
what does the facia lata attach onto in static facial reanimation?
both corners of mouth
what does the facia lata attach onto in static facial reanimation?
both corners of mouth
why are endoscopic techniques use?
- minimise the risk of infection
- minimise scarring and recovery time
