clinical anatomy of the face Flashcards
what is the cranium?
the head
what are the two parts of the skeleton of the head?
- neurocranium
- viscerocranium
what is the neurocranium?
bony covering of the brain and meninges (layers surrounding brain and spinal cord)
what is the roof of the neurocranium called?
the calvaria
what is the floor of the neurocranium called?
cranial base
how many bones make up the neurocranium and what are they called?
eight
- one frontal
- one ethmoid
- one sphenoid
- one occipital
- two temporal
- two parietal
what does pneumatised mean?
air within the bones
which bones of the cranium are pneumatised?
frontal, ethmoid, sphenoid, temporal and maxillary
which bones of the cranium are in the form of paranasal sinuses?
frontal, ethmoid, sphenoid and maxillary
what is the connection between the frontal and parietal bones?
coronal suture
what is the connection between the parietal and occipital bones?
lambdoidal suture
what is the connection between the parietal and temporal bones?
squamous suture
skull diagram…
what is the ear canal called?
external auditory meatus
what does the viscerocranium make up and how many bones is there in it?
the facial skeleton- 14 bones
where are the mastoid air cells found?
the temporal bone (mastoid is behind the ear)
what is the small bone in the skull where muscles attach onto?
styloid process
what is the crash impact barrier part of the skull?
zygomatic bone
what is the weakest point of the skull?
pterion- where the frontal, parietal, sphenoid and temporal bones meet
what can happen as a result of trauma to the pterion?
rupture of the middle menigeal vessels resulting in a extra-dural haemorrhage (lucid interval after injury)
what % of non-verbal communication does our face contribute to?
80-90%
what is the orifaces?
nose, lips, chin
does the facial skeleton or calvaria take longer to grow?
facial skeleton
what is the calvaria?
top part of the skull
what are triangles of the neck important for?
to identify lumps
regions of head and neck?
regions of the face…
what are the divisions of the 31 pairs of spinal nerves?
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
where do the cranial nerves arise from?
the brain and brainstem
which nerve supplied sensory innervation to the face?
trigeminal
which nerve supplies motor innervation to the muscles of mastication?
trigeminal
which nerve supplies the muscles of facial expression?
facial
what are the three branches of the trigeminal nerve?
ophthalmic Va, maxillary Vb and mandibular Vc
what does the ophthalmic nerve branch of the trigeminal nerve innervate?
- Forehead and scalp
- Frontal and ethmoidal sinus
- Upper eyelid and its conjunctiva
- Cornea
- Dorsum of the nose
what does the maxillary nerve branch of the trigeminal nerve innervate?
- 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 does the mandibular nerve branch of the trigeminal nerve innervate?
Sensory supply:
- Mucous membranes and floor of the oral cavity
- External ear
- Lower lip
- Chin
- Anterior 2/3 of the tongue
- Lower molar, incisor and canine teeth and the associated gingiva
Motor Supply:
- Muscles of mastication; medial pterygoid, lateral pterygoid, masseter, temporalis
- Anterior belly of the digastric muscle and the mylohyoid muscle (these aresuprahyoid muscles)
- Tensor veli palatini
- Tensor tympani”
what is HSV?
Herpes simplex – virus caused by herpes simplex virus. There are 2 types, Type 1 and Type 2 and around the mouth, Type 1 is more common the mouth and Type 2 around the genitalia.
It could cause a cold sore around the corners of the mouth, affecting the maxillary or mandibular territories.
what is VZV?
Varicella zoster virus (VZV): Primary varicella zoster infection results in chickenpox and can cause lung and airway disease like bronchitis or pneumonia. When it resolves the virus lays dormant in the ganglia (collection of cell bodies) and can reactivate in 10-20% of people resulting in shingles or herpes zoster.
what are the muscles of mastication?
masseter, temporalis, pterygoids
where is the masseter?
zygomatic arch to mandible
what is the function of the masseter?
elevates the mandible and closes the mouth
where is the temporalis?
from frontal/parietal bones to coronoid process of mandible
what is the function of the temporalis?
elevates the mandible and closes the mouth
ALSO
retracts the mandible
what is the function of the lateral pterygoids?
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. ONLY ONE WHICH OPENS MOUTH
what is the function of the medial pterygoids?
elevate mandible and close the mouth
how would you test the muscles of mastication clinically?
ask patient to clench jaw tightly
how many muscles are in the face?
43
what nerve supplies the facial muscles?
facial nerve VII
what is different about the facial muscles?
they are attached to the bone/fascia (tissue) then to the skin directly
- this allows for facial expression
what are the muscles around the lips and mouth important for?
clear speech
what are the muscles of the mouth/cheeks?
- elevators, retractors, evertors (pout) of upper lip
- depressors, retractors, evertors of lower lip
- obicularis oris
- buccinator
where is the obicularis oris?
around the mouth
- originates from the maxilla and cheek muscles and inserts into the lips
which muscle is involved in pursing of the lips?
obicularis oris
what nerve supplies the obicularis oris?
buccal branch of the facial nerve
where is the buccinator muscle?
cheek
- originates from the maxilla and mandible and extends down to blend with the obicularis oris and skin of the lips
what is the function of the buccinator muscle?
pulls in cheeks, pushing food into middle of the oral cavity
what nerve supplies the buccinator muscle?
buccal branch of the facial nerve
what is the muscle which moves the eye?
obicularis oculi
what are the two parts of the obicularis oculi?
orbital (strong thicker closing part) and palpedral (in eyelids- soft closing eg blinking)
what muscle allows some people to move their ears?
auricular muscles
what are the three major structures which pass through the parotid gland?
- external carotid artery
- retromandibular vein
- facial nerve
what enters the oral cavity opposite the second upper molar?
parotid duct
what causes mumps?
a paramyxovirus
- it can cause swelling of the parotid gland, and lymph nodes, including those inside the parotid gland
- swellings are painful and give a hamster appearance, and are sore as they stretch the fascia (connective tissue) which surrounds the parotid gland
what can mumps cause?
deafness, infertility and meningitis
- it is usually a self limiting condition and clears itself, and analgesia and bed rest are the only supportive treatments available
what is bell’s palsy?
complete paralysis one ONE SIDE only
- most common cranial neuropathy
- diagnosed only if no specific cause is identified
- due to swelling of facial nerve through the stylomastoid foramen
what are available treatments for bell’s palsy?
prednisolone (steroid)
acyclovir
what are the 5 main branches of the facial nerve?
- temporal
- zygomatic
- buccal
- marginal mandibular
- cervical
what does the temporal branch of the facial nerve innervate?
the frontalis, orbicularis oculi and corrugator supercilli
what does the zygomatic branch of the facial nerve innervate?
orbicularis ocui
what does the buccal branch of the facial nerve innervate?
orbicularis oris , buccinator and zygomaticus muscles
what does the marginal mandibular branch of the facial nerve innervate?
mentalis muscle
what does the cervical branch of the facial nerve innervate?
the platysma
what is the risk of removing the parotid gland (tumour)?
the facial nerve branches could be cut
what does ectomy mean?
surgical removal
what are the two ways of doing a parotidectomy?
anterograde or retrograde
what is an aterograde parotidectomy?
identifying main trunk of facial nerve and tracing out smaller branches PREFFERED
what is a retrograde parotidectomy?
identifying smaller branches of facial nerve and tracing them back to the main trunk
what should be done before operating need parotid gland?
- mark mandible angle
- mark neck
what is likely to be done during an operation which could potentially damage the facial nerve?
the great auricular nerve
what does facial reanimation treatment depend on?
- level of injury
- duration of paralysis ( before 12 months)
what are the types of facial reanimation?
- immediate/ early reconstruction
- intermediate reconstruction
- late reconstuction
which facial reconstructions are dynamic?
(bring back movement)
early and intermediate
what is a static facial reconstruction?
(late)
bring back facial symmetry
what is a hypoglossal facial anastomosis (joining up again)?
joins CN XII and CN VII if CN VII stops working
- used for patients with intermediate length paralysis
- side to end anastomosis is most popular
what does the hypoglossal nerve innervate?
tongue muscles
where is skin taken from for static facial reanimation?
thigh- fascia lata (attached to corner of mouth)
