ICL 11.0: Muscles of the Face & Infratemporal Flashcards
what are the 5 groups of muscles of the face?
- epicranial group
- circumorbital and palpebral group
- auricular group
- nasal group
- buccolabial group
which muscles are in the epicranial group?
- epicranius aka occipitofrontalis
2. temporoparietalis
which muscles are in the circumorbital and palpebral group?
- orbicularis oculi
- levator palpebrae superioris
- corrugator supercilii
which muscles are in the auricular group?
- auricularis anterior
- auricularis superior
- auricularis posterior
which muscles are in the nasal group?
- procerus
- nasalis
- depressor septi
which muscles are the buccolabial group?
- orbicularis oris
- levator labii superioris
- levator Labii superioris alaeque nasi
- risorius
- zygomaticus major
- zygomaticus minor
- mentalis
- levator anguli oris
- depressor labii inferioris
- depressor anguli oris
- buccinator
where do facial muscles originate and attach too?
they arise from the facial bones and attached to the skin or encircle facial orifices
what is the innvervation of the facial muscles?
all of them are innervated by the facial nerve
EXCEPT levator palpebrae superiors which is innervated by the oculomotor nerve
what is the route of the facial nerve?
it leaves the skull through stylomastoid foramen, and soon pierces the parotid gland
within the parotid gland, it ramifies into terminal branches which leave the parotid gland from the different borders and run in the superficial fascia of the face to reach their target muscles
this is very close to the TMJ so it is at risk if there is a fracture/dislocation of TMJ
what are the 7 branches of the facial nerve?
- greater petrosal nerve
- nerve to the stapedius
- chorda tympani
- osterior auricular
- nerve to posterior belly of digastric muscle
- nerve to stylohyoid
- five terminal branches for the muscles of facial expression
what are the 5 terminal branches of the facial nerve?
- temporal
- zygomatic
- buccal
- marginal mandibular
- cervical
“To Zanzibar By Motor Car”
what is facial palsy?
aka Bell’s Palsy
it is a type of facial paralysis that results in an inability to control the facial muscles on the affected side
symptoms may include include muscle twitching, weakness, or total loss of the ability to move one or rarely both sides of the face, drooping of the eyelid, a change in taste, pain around the ear, and increased sensitivity to sound
cause is unknown
what are the symptoms of Bell’s palsy?
- paralysis of the orbiculares oculi which leads to an inability to close the eye –> serious issue because it leads to eye dryness and corneal ulceration
- paralysis of the orbicularis oris = angle of the mouth sags in the affected side, and there may be drooling in that side
- paralysis of the buccinator = accumulation of food between the cheek and the teeth on the affected side; flattened nasolabial fold on effected side
what is the arterial supply of the face? what is the route that is takes?
- facial artery
2. superficial temporal artery
what is the route of the facial artery?
its a branch of the external carotid artery
it runs part of its course in the digastric triangle and reach the face at the lower anterior angle of the masseter where its pulse can be palpated
it kind of travels through the mouth up the nose to the eye where it ends near the medial angle of the orbit by becoming the angular artery
what are the branches of the facial artery?
- ascending palatine
- tonsillar
- inferior labial*
- superior labial*
- lateral nasal*
what is the route of the superficial temporal artery?
it’s one of the terminal branches of the external carotid artery (the other is the maxillary artery)
it arises inside the parotid gland near the neck of mandible, runs upward and crosses the zygomatic arch and runs in the superficial fascia of the face, supply the skin of face and part of the scalp
it basically runs up the side of the face infant of the ear
you can feel its pulse at the tragus
what are the branches of the superficial temporal artery?
- transverse facial (it goes and anatomoses with the facial artery)
- frontal (anterior branch)
- parietal (posterior branch)
which veins drain the face?
facial vein
the supraorbital and supratrochlear veins form the angular vein at the root of the nose –> the angular vein descend over the medial side of orbit to become the facial vein at the lower side of the medial margin of the orbit
then the facial veins descends and in the digastric triangle it joins the anterior division of the retromandibular vein to form the common facial vein
the common facial vein then drains into the internal jugular vein
how does the facial vein communicate with the cavernous sinus?
the facial vein communicates with cavernous sinus through two routes
- superior and inferior ophthalmic veins connect the angular vein in the orbital region to the cavernous sinus
- the deep facial veins between the nose and mouth connect the facial vein to the pterygoid plexus of veins which, in turn, connects to the cavernous sinus
what is cavernous sinus thrombophlebitis?
the dangerous triangle of the face = the triangle formed by the nose and mouth
face infections in the area of the dangerous triangle could cause facial vein phlebitis with secondary thrombophlebitis (blood clot) in the internal jugular vein
infected thrombi may reach to cavernous sinus, causing thrombophlebitis of cavernous sinus which may lead to:
- exophthalmos = bulging eyeball
- diplopia/ophthalmoplegia = double vision
- mydriasis and loss of near vision reflexes
- pain, paresthesia or loss of sensation in the distribution of ophthalmic or maxillary divisions of trigeminal nerve
- death
what are the 3 pairs of salivary glands?
- parotid
- submandibular
- sublingual
which salivary gland is the largest?
parotid
the parotid glad is surrounded by a tough capsule (parotid sheath), derived from the investing layer of the deep cervical fascia
what is the function of the parotid gland?
it’s a salivary gland drains saliva through the parotid duct
it’s located under the ear and anterior to the sternocleidomastoid
what is sialadentis?
inflammation of the parotid gland
associated with pain, tenderness, redness, and gradual, localized swelling of the affected area
where is the parotid duct located?
the parotid ducts emerges from the anterior border of parotid
it runs over the masseter muscle and pierces the buccinator muscle to reach the oral cavity
the parotid ducts opens in the buccal mucosa opposite the maxillary 2nd molar tooth
occasionally, there is extension of the glandular tissue of the parotid over the parotid duct called accessory parotid gland
what are sialoliths?
stones in the parotid duct
what is sialography?
imaging the parotid after injecting radiographic contrast medium
what are the borders of the parotid gland?
the parotid gland extends from external auditory meatus superiorly to the angle of the mandible inferiorly, and from the ramus of the mandible anteriorly to the mastoid process posteriorly –> it’s wedge shaped
it has 3 surfaces = lateral, anteromedial and posteromedial
it has 3 borders = anterior, posterior and medial borders
what is the parotid bed?
a group of structures related to the medial border of the parotid gland
- styloid process
- stylohyoid muscle
- internal carotid
- vagus nerve
- glossopharyngeal nerve
- lateral wall of the pharynx
which structures are at risk during surgery on the parotid gland?
- facial nerve
- retromandibular vein
- external carotid artery
these 3 structures run within the parotid gland and they could be damaged during surgery
which muscles surround the parotid?
posteromedial:
1. posterior belly of the digastric
- sternocleidomastoid
- mastoid process
anteromedial surface:
1. masseter
- medial pterygoid muscle
- ramus of the mandible
how is the parotid gland parasympatheticlly innervated?
glossopharyngeal nerve –> tympanic branch –> lesser petrosal nerve –> otic ganglion –> postganglionic and parasympathetic which run in the auricolotemporal nerve –> parotid gland
most important!
how is the parotid gland sympathetically innervated?
sympathetic postganglionic fibers are derived from superior cervical ganglion, reaching the gland through sympathetic plexus around external carotid artery
what is the sensory innervation of the parotid gland?
great auricular nerve and auriculotemporal nerve
what is Frey’s syndrome?
a rare neurological disorder resulting from damage to or near the parotid glands responsible for making saliva, and from damage to the
*auriculotemporal nerve often from surgery
when the nerves heal they get all criss crossed between the parasympathetic, sympathetic and sensory innervation so when you smell something good instead of salivating you start sweating
symptoms include sweating and flushing on the cheek or temple, or near the ear, particularly when eating foods with more-intense flavors, such as sour, spicy, or salty foods
what are the boundaries of the temporal fossa?
temporal lines to the zygomatic process of the frontal bone to the zygomatic arch and then loops back around to the temporal lines
what are the contents of the temporal fossa?
the temporalis muscle along with its blood and nerve supply = deep temporal arteries and nerves
what is the infratemporal fossa?
an irregular area on the lateral surface of the skull deep below the zygomatic arch and deep to the ramus of the mandible
it goes from the ramus of the mandible to the lateral pterygoid plate to the posterior surface of the maxilla to the mastoid/styloid process of the temporal one
it goes from the infratemporal surface of the greater wing of the sphenoid down to the medial pterygoid attachment o the angle of the mandible
what are the contents of the infratemporal fossa?
MUSCLES
1. Medial Pterygoid
- Lateral Pterygoid
- Temporalis muscle tendon
BLOOD VESSELS
1. Maxillary artery and some of its branches
- Pterygoid plexus of veins
- Maxillary vein and its tributaries
NERVES
1. Mandibular nerve and its branches
- Otic ganglion
- Posterior superior alveolar nerve (branch of maxillary nerve)
which 4 muscles are responsible for chewing?
- masseter
- temporalis
- medial pterygoid muscle
- lateral pterygoid muscle
what innervates the muscles involved in mastication?
the mandibular division of the trigeminal nerve
- masseter
- temporalis
- medial pterygoid muscle
- lateral pterygoid muscle
where is the masseter located? what is its action?
ocated in the face over the lateral surface of the ramus of the mandible – it basically covers the ramus
it goes from the zygomatic arch to the angle of the mandible
muscle is overlapped by the parotid gland posteriorly, and crossed by parotid duct, branches of facial nerve
it’s a powerful elevator of the mandible to occlude the teeth, the muscle provides minimal protrusion
what is the innvervation of the masseter?
V3 = mandibular division of trigeminal nerve
where is the temporalis located? what is its action?
Temporalis muscle is located in the temporal fossa, occupying all the temporal fossa, and it is tendon is in the infratemporal fossa
so it goes from the interior temporal line and takes up the whole floor of the temporal fossa down to the coronoid process of the mandible
elevates and retrudes the mandible to close the mouth