Muscles of Mastication and Infratemporal Fossa Flashcards
Where does the temporalis muscle insert
cornonoid process of the mandible
The muscles of mastication develop from which branchial arch
what nerve innervates that arch
what artery supplies the muscles of mastication
1st branchial arch
trigeminal nerve (mandibular division V3) - named according to hte corresponding muscle
second part of maxillary artery (named according to corresponding muscle)
What covers the medial surface of the medial pterygoid and splits around the lateral pterygoid
pterygoid fascia
what is the pterygospinous ligament
may be formed by pterygoid fascia between the medial and lateral pterygoid muscles
the pterygoid fascia is continuous with the _______, ________, and the _______
stylomandibular ligament, deep parotid fascia, and the superficial fascia of the neck
In fracture dislocations of the mandible anterior to the angle of the mandible, what causes the proximal portion of the mandible to displace upward and forward?
the masseter muscle
What nerve innervates the buccinator muscle
CN VII
what is the buccinator’s role in mastication
pushes food onto chewing portion of the teeth,
if paralyzed, food is pushed between teeth and cheeks
what structures pass between the two heads of the lateral pterygoid
maxillary artery
long buccal nerve
what structures pass between the medial and lateral pterygoids
the inferior alveolar and lingual nerves
Describe the jaw jerk (masseteric) reflex mechanism
one synapse only
rapid depression of the chin
stretching neuromuscular spindle in masseter
maseteric nerve to mesencephalic nucleus of V (sensory nucleus)
motor nucleus of V
masseteric nerve to neuromuscular endplates in the masseter muscle
contraction of masseter muscle
what is the jaw jerk reflex
rapid depression of the chin results in a closing of the mouth
What is responsible for action of normal opening of the mouth
gravity,
lateral pterygoid
what muscles are responsible for wide opening of the mouth
lateral pterygoid,
suprahyoid
what muscles are responsible for closing the mouth
temporalis
masseter
medial pterygoid
How many different joint cavities make up the TMJ. What are they separated by?
to separate disks subdivided by an articular disk
What type of joint is the superior joint of the TMJ
gliding joint
between mandibular fossa and articular tubercle, and the articular disk
capsule is thin and loose to permit extensive sliding movement
MOBILE
what type of joint is the inferior joint of the TMJ
hinge type joint between the articular disk and the mandibular condyle
lower capsule is strong and tight
What is the articular disk of the TMJ attached to
the sphenomeniscus muscle and the strong lateral (collateral) ligament
What ligament makes it much easier to open the mouth
stylomandibular ligament
from the apex of the syloid process to the inner surface of the angle of the mandible
biomechanically changes the transverse axis of rotation from a line between the mandibular condyles to a line between the lingulae
What are two critical developments in the skull
development of dentition
development of paranasal sinuses
Newborn has a mental angle of
why
175 degrees, because the alveolar bone is only a shell and the basilar bone is thin
four year old child has a mental angle of
140 degrees
adult has a mental angle of
why
110-120 degrees
due to the development of dentition
What type of changes in the mental angle do we see in senior patients
regressive change in the mental angle to about 140 degrees.
an edentulous condition with corresponding alveolar bon resorption is causative
Fracture of the neck of the mandible may compromise
maxillary artery
maxillary vein
or auriculotemporal nerve (sideburn anesthesia)
fracture of the ramus of the mandible may damage
lingual or inferior alveolar nerves
fracture of the body of the mandible would compress
the inferior alveolar nerve and vessels
What is the terminal branch of maxillary artery
What does it supply
sphenopalatine artery
posterior 2/3 of the nasal cavity
infratemporal fossa contains
tendon of tempoalis muscle medial and lateral pterygoid muscles maxillary artery and branches pterygoid venous plexus mandibular division of V (V3)
What are the two terminal branches of external carotid artery
superficial temporal and maxillary
what artery do we care about that is a branch of maxillary
why
middle meningeal artery
with head trauma it can cause epidural hematomas
Know the mandibular nerve schematic
the angel diagram
long buccal n passes between what muscle heads
the two heads of lateral pterygoid muscle
where does the distal portion of buccal nerve course
deep to tempoprobuccinator band, a portion of the temporalis tendon that is attached to the buccinator muscle
What does the buccal nevrve supply
GSA fibers to the epithelia of the inner and outer cheek
What nerve originates as two roots which encircle the middle meningeal artery
the auriculotemporal nerve
at the point where auriculo temporal nerve encircles the middle meningeal artery, it receives what sort of autonomic supply from where, and where do they terminate?
postganglionic sympathetic fibers from middle meningeal plexys, which will terminate in the parotid gland
GSA to anterior 2/3 of the tongue
lingual nerve (V3)
chorda tympany nerve joins lingual nerve where
medial to the mandibular condyle
Chorda tympani courses with lingual nerve to supply
SVA fibers to the anterior 2/3 of tongue
GVE parasympathetic fibers to the submandibular and sublingual glands
