007 the face and mouth Flashcards
what are the 2 fossa superiorly to mandible?
- temporal fossa = between zygomatic arch, temporal, sphenoid and frontal bones and lateral surface of the mandible
- infratemporal fossa = between pharynx and medial to ascending ramus, beneath the greater wings of the sphenoid
what are the arteries in the infratemporal fossa?
- the terminal branches of the external carotid artery divide in the infratemporal fossa:
= maxillary artery
= middle meningeal artery
= inferior alveolar artery
= superior temporal artery
what are the veins in the infratemporal fossa?
- pterygoid plexus drains the region, receiving blood from the intracranial region, occipital bone, basilar part and inferior orbital veins
- cavernous sinus and facial vein drains rest
- collects into the retromandibular vein and internal/external jugular vein
what is the clinical significance of the facial veins draining into the cavernous sinus?
- many infections present in the head and neck, meaning that they could be carried in the facial veins into the cavernous sinus where it can spread to the brain
what are the cranial nerves in the infratemporal fossa?
- trigeminal nerve (V)
- facial nerve (VII)
what are the trigeminal nerve branches in the infratemporal fossa?
- mandibular division of CNV leaves brain through foramen ovale into infratemporal fossa
- gives iff some tiny sensory branches to mastoid air cells
- otic ganglion just below foramen ovale = parasympathetic ganglion for parotid gland
- long buccal nerve = sensory for inside and outside cheek
- lingual nerve = tongue sensory
- inferior alveolar nerve = sensory for teeth, lower lip, chin = branches to mylohyoid and digastric
- auriculotemporal nerve = sensory to ear, tympanic membrane, temple
what are the facial nerve branches in the infratemporal fossa?
- motor fibres from facial nerve to face muscles via stylomastoid foramen
- chorda tympani, joins the lingual nerve to the submandibular salivary glands and taste fibres in tongue
what are the 3 salivary glands?
- parotid, submandibular, sublingual
what type of gland are salivary glands?
- exocrine (duct) glands
where are the salivary glands?
- parotid = anterior to ear, on top of masseter muscle, ends at inferior margin of mandible
- sublingual = beneath the anterior 1/3 of the tongue, behind bottom front teeth
- submandibular = backward c shape beneath the posterior 1/3 of tongue, lies on mylohyoid
what is the overview of the innervation of the salivary glands?
- salivary secretion is under parasympathetic stimulation
- however sympathetic can also increase salivation by stimulating more blood flow into glands (T1-3 and cervical ganglion)
what is the submandibular gland innervated by?
facial nerve and submandibular ganglion
what is the sublingual gland innervated by?
facial nerve and submandibular nerve
what is the innervation of the parotid gland?
- facial nerve motor branches
- parasympathetic innervation is from the glossopharyngeal nerve (IX) via the lesser petrosal nerve travelling through the foramen ovale to the otic ganglion
- from there, fibres travel with the auriculotemporal nerve (Viii)
-sympathetic innervation is via the superior cervical ganglion and fibrs travel in the auriculotemporal nerve too
what is the name of the jaw bone?
mandible
what does the mandible join to?
temporal bone of the skull
what is the joint between the mandible and the temporal bone?
- temporomandibular joint (TMJ)
- a synovial joint between the glenoid fossa of the temporal bone
what is a?
head of mandible / condylar process
what is b?
neck of mandible
what is c?
mandibular notch
what is d?
coronoid process
what is e?
oblique line
what is f?
mental protuberance
what is g?
mental tubercle
what is h?
mental foramen
what is I?
groove for facial artery
what is J?
angle
what is k?
attachment of masseter
what is L?
lingula
what is m?
mandibular foramen
what is n?
mylohyoid groove
what is o?
attachment of medial pterygoid
what is p?
submandibular fossa
what is q?
sublingual fossa
what is r?
superior and inferior mental spines
what is s?
digastric fossa
what is T?
mylohyoid line
what are the 3 parts of the mandible?
body = chin to angle
ramus = angle up towards temporal bone
alveolar process = teeth sockets
what are the different movements of the 2 compartments of the TMJ?
- upper compartment = anterior/posterior gliding of the mandible condyle , and the articular disc moves with the mandibular condyle
- lower compartment = rotation of the mandibular condyle
what are the 4 muscles of mastication?
- masseter, temporalis, medial pterygoid and lateral pterygoid
what is the origin and insertion of the masseter muscle?
origin = zygomatic arch/ maxillary process of zygomatic bone
insert = lateral surface of ramus of mandible
what is the innervation of the masseter muscle?
masseteric nerve = branch off mandibular nerve = branch off trigeminal nerve
what is the action of the masseter muscle?
- elevation of mandible
what is the origin and insertion of the temporalis muscle?
origin = bone of temporal fossa and temporal fascia
insertion = coronoid process of mandible, anterior ramus of mandible almost down to the teeth
what is the innervation of the temporalis muscle?
deep temporal nerves = branch off mandibular nerve = branch off trigeminal
what is the action of the temporalis muscle?
- elevation and retraction of the mandible
what is the origin of the medial pterygoid muscle?
deep head = medial surface of lateral plate of pterygoid process and pyramidal process of palatine bone
superficial head = tuberosity of the maxilla and pyramidal process of palatine bone
what is the insertion of the medial pterygoid muscle?
medial surface of mandible near the angle ( behind bone)
what is the innervation of the medial pterygoid muscle?
nerve to medial pterygoid = branch from mandibular nerve = branch of trigeminal nerve
what is the action of the medial pterygoid muscle?
elevation and side to side movement of mandible
what is the origin of the lateral pterygoid muscle?
- upper head = roof of infratemporal fossa
- lower head = lateral surface of the lateral plate of the pterygoid process on maxilla
what is the insertion of the lateral pterygoid muscle?
capsule of TMJ at the articular disc at the neck of the mandible
what is the innervation of the lateral pterygoid muscle?
nerve to lateral pterygoid = branch from mandibular branch = branch of trigeminal nerve
what is the action of the lateral pterygoid muscle?
protrusion and side to side movements of mandible
what are the 4 movements of the mandible?
protrusion (forward)
retraction (backwards)
elevation (up)
depression (down)
what muscles protrude the mandible?
lateral and medial pterygoid
what muscles retract the mandible?
posterior fibres of temporalis
deep part of masseter
geniohyoid
digastric
what muscles elevate the mandible?
temporalis
masseter
medial pterygoid
what muscles depress the mandible?
digastric
geniohyoid
mylohyoid
(gravity)
what are all the bones that make up the face?
- frontal
- temporal
- zygomatic
- sphenoid
- maxilla
- mandible
- hyoid
- lacrimal
- ethmoid
- palatine
- nasal
what is a?
frontal bone
what is b?
temporal bone
what is c?
optic canal
what is d?
middle nasal concha of ethmoid bone
what is e?
inferior nasal concha
what is f?
vomer (of zygomatic bone)
what is g?
mandible bone
what is h?
maxilla bone
what is I?
zygomatic bone
what is J?
lacrimal bone
what is k?
ethmoid bone
what is L?
sphenoid bone
what is m?
nasal bone
what is n?
parietal bone
what are all the facial expression muscles innervated by?
facial nerve (CN VII)
what is the orbital face muscle and what are the 2 parts?
- orbicularis oculi
= orbital part = broad ring that encircles orbital orifice and extends outward beyond orbital rim
= palpebral part = in eyelids, muscle fibres originate in the medial corner and run laterally
what do the 2 parts of the orbicularis oculi do?
- orbital part = closes eyelids forcefully
- palepbral part = closes eyelids gently
what is the orbicularis oris and what does it do?
- ring of muscle around the lips
- closes and protrudes lips (pout)
what is the buccinator and what does it do?
- forms muscular part of cheek and used to expand cheek with air and move food around in mouth/cheek
- muscle fibres blend into orbicularis oris
what are the muscles of mastication supplied by?
mandibular division of trigeminal nerve (V3)
(temporalis, masseter and pterygoids)
describe the sensory innervation of the face
- trigeminal nerve branches
- Opthalmic = 1 = forehead, scalp, upper eyelid, nose
- maxillary = 2 = lower eyelid, cheek, upper lip
- mandibular = 3 = external acoustic meatus, eardrum, temple, lower half of cheek, lower lip, chin
what are the motor branches of the facial nerve?
temporal, zygomatic, buccal, marginal mandibular, cervical
what does the temporal motor facial branch supply and travel?
- exits from superior border of parotid gland and supplies muscles in temple, forehead and supra-orbital area
what does the zygomatic motor facial branch supply and travel?
- emerges from anterosuperior border of the parotid gland to supply muscles in the infra-orbital area, lateral nasal area and upper lip
what does the buccal motor facial branch supply and travel?
- emerges from anterior border of parotid gland, supplies muscles in cheek, upper lip and corner of mouth
what does the marginal mandibular motor facial branch supply and travel?
- emerges from anteroinferior border of parotid gland to supply muscles in lower lip and chin
what does the cervical motor facial branch supply and travel?
- emerges from inferior border of the parotid gland to supply the platsyma
describe the pathway of the facial nerve from the cranial cavity to before it branches
- sensory and motor roots leave the cranial cavity through the internal acoustic meatus
- after entering the facial canal, the 2 roots fuse and form the facial nerve
- the nerve then enlarges and forms the geniculate ganglion where it gives off the greater petrosal nerve going medially
- the facial nerve also continues along the bony canal down the temporal bone giving off the nerve to the stapedius and chorda tympani before exiting the skull through stylomastoid foramen
what does the chorda tympani supply?
- facial nerve branch
- taste fibres from anterior 2/3 of tongue
- parasympathetic = labial glands, lingual glands, sublingual gland, submandibular gland
what does the greater petrosal nerve supply?
- facial nerve branch
- lacrimal gland, mucus glands of nose, maxillary sinus, palate(parasympathetic)
what does the lesser petrosal nerve supply?
glossopharyngeal branch
parotid gland
describe the arterial supply to the face (briefly)
- external carotid artery branches to give off facial artery around the lower border of the mandible which then branches superiorly and medially up to nose/eye
- maxillary artery also branches off external carotid artery which branches across chin/upper lip/lower eye region
-transverse facial artery = branch of superficial temporal artery, branch of external carotid artery near zygomatic arch
-opthalmic artery, branch of internal carotid artery supply skin over zygomatic bone, eye, nose and forehead
describe the venous system of the face
- facial vein is the major vein draining the face
- originated in corner of eye and ends down inferior rim of mandible into internal jugular vein
- cavernous sinus behind temporal lobe and pterygoid plexus behind ramus of mandible also join in this network
describe the 3 groups of lymph nodes in the face
- submental nodes = inferior and posterior to chin
- submandibular nodes = superficial to submandibular gland and inferior to body of mandible
- pre-auricular and parotid nodes = anterior to ear
what are the oral cavity boundaries
roof = hard and soft palate
floor = mylohyoid muscle
anterior boundary = teeth and lips
posterior-lateral boundary = palatoglossal arches
walls = cheeks
how do teeth sit in the mouth?
- teeth are attached to sockets (alveoli) in 2 elevated arches of bone on the mandible and maxilla
- gingivae (gums) are specialised regions of oral mucusa that surround the teeth and alveolar bone
what are the different types of adult teeth?
- incisors at the front
- canines
- premolars
- molars at the back
what is the innervation of the teeth?
trigeminal branches maxillary and mandibular for top and bottom rows
what are the 2 spaces in the mouth?
- vestibule/buccal cavity = defined by outer surface of teeth and alveolar ridges, the cheeks and the lips (often a collapsed space)
- oral cavity proper = main opening of the mouth, when mouth shut, almost completely filled by the tongue
how is the tongue divided?
- into anterior 2/3rds(oral cavity) and posterior 1/3rd (oropharynx) by the terminal sulcus
- muscles of the left and right half are separated by a midline fibrous septum/raphe
describe the taste somatosensory innervation of the tongue
- anterior 2/3 = facial nerve branch chorda tympani
- posteiror 1/3 = glossopharyngeal
- valleculae = vagus
what is the touch/temp/pain somatosensory innervation of the tongue?
- anterior 2/3 = trigeminal nerve, mandibular division, lingual nerve
- posterior 1/3 = glossopharyngeal
- valleculae = vagus
what is the motor innervation of the tongue?
- all tongue muscles except palatoglossus (vagus) are innervated by the hypoglossal nerve
what is the sign for a damaged hypoglossal nerve?
tongue deviated towards side of lesion (overpowering genioglossus muscle intact)
what are the intrinsic muscles of the tongue?
superior longitudinal, vertical, transverse, inferior longitudinal
what do the intrinsic muscles of the tongue do?
- attach to the tongue midline/septum, raphe and mucosa (no bone attachments)
- lengthen, shorten, curl, uncurl, flatten and round the tongue
what are the extrinsic muscles of the tongue?
- genioglossus, hypoglossus, styloglossus, palatoglossus
what do the extrinsic muscles of the tongue do?
- attach the tongue to the hyoid bone, styloid process of temporal bone, mandible and soft palate
- protrude, retract, depress and elevate the tongue
