Deep Face Flashcards
The pterion of the skull refers to the junction of what? Is it a weak or strong spot in the skull?
- Junction of temporal, parietal, sphenoid, and frontal bones
- Weak spot (dangerous because middle meningeal artery runs beneath)
What does the temporalis muscle attach to and what is its function?
- Attaches at coronoid process of mandible
- Function is to elevate the mandible during normal talking
Are the temporalis and masseter horizontally or vertically oriented?
Their fibers are vertically oriented.
What is the origin and insertion of the masseter muscle?
- Origin: under zygomatic arch
- Insertion: entire ramus of mandible
What are the bones of the temporal fossa?
- Parietal
- Temporal
- Sphenoid (greater wing)
- Frontal (very small portion)
What is the temporal fossa?
A depression on the temporal region of the skull, above the zygomatic arch.
What is the most important thing to know about the infratemporal fossa?
It is located beneath the zygomatic arch and behind the ramus of the mandible.
What are the main contents of the infratemporal fossa?
- Medial and lateral pterygoid muscles
- Maxillary artery + branches
- Mandibular divison of trigeminal n. + branches
- Chorda tympani
- Glossopharyngeal n. + branches
What are the muscles of mastication?
- Medial and lateral pterygoid
- Masseter
- Temporalis
What is the function of the lateral pterygoid muscle?
- Bilateral: protrude mandible
- Unilateral: produces side-to-side grinding
What is the function of the medial pterygoid muscle?
- Bilateral: protrude and elevate mandible
- Unilateral: produces side-to-side movements
What are the muscles of mastication innervated by?
Mandibular branch of CN V3.
Where do the medial and lateral pterygoid muscles originate?
- Medial: medial surface of LATERAL pterygoid plate
- Lateral: lateral pterygoid plate (inferior head) and greater wing of sphenoid (superior head)
What is the most important muscle in protraction of the jaw?
lateral pterygoid (which is assisted by medial pterygoid)
Which muscles are involved in retraction of the jaw?
- Posterior fibers of temporalis
- Deep fibers of masseter
What is the most important muscle in depression (opening) of the jaw?
lateral pterygoid
What is an important contributing factor to depression of the jaw? (NOT a muscle)
gravity
Which movements of the jaw does the lateral pterygoid control?
- Protraction
- Depression
Which muscles are involved in elevation of the jaw?
- Temporalis
- Masseter
- Medial pterygoid
Do the masseter and temporalis provide ipsilateral or contralateral movement?
ipsilateral
Do the pterygoid muscles provide ipsilateral or contralateral movement?
contralateral
What type of joint is the TMJ?
a synovial joint (more specifically, a modified hinge joint)
Each TMJ is divided into ________ by its _______.
a superior and inferior compartment; articular disc
What is the first movement of the TMJ?
- Lower compartment
- Hinge movement (rotation) to open jaw 1 finger breadth
What is the second movement of the TMJ?
- Upper compartment
- Sliding/gliding movement along the eminence, leading to full opening and protrusion of mandible
Why does the articular disc move with the head of the mandible?
To prevent bone on bone contact.
What does the articular disc attach to?
Lateral pterygoid muscle and joint capsule.
The maxillary artery is divided into 3 parts by which muscle?
Pterygoid muscle
What are the main branches of the maxillary artery?
MIDBIPS
- Middle meningeal
- Inferior alveolar
- Deep temporal (ant. and post.)
- Buccal
- Infraorbital
- Posterior superior alveolar
- Sphenopalatine
Which nerve supplies the special visceral afferent (SVA) fibers for taste from the anterior 2/3rds of the tongue?
Chorda tympani
What is the function of the masseter muscle?
close (elevate) and protrude the jaw
What is the origin and insertion of the medial pterygoid?
- Origin: lateral pterygoid plate (deep) and maxilla and pyramidal plate (superficial)
- Insertion: near angle of mandible
What is the origin and insertion of the lateral pterygoid?
- Origin: infratemporal crest (superior) and lateral pterygoid plate (inferior)
- Insertion: TMJ (superior) and mandible (inferior)
Which nerves pass between the medial and lateral pterygoid muscles?
lingual and alveolar nerves
Which pterygoid muscle opens the jaw and which closes it? What is the action they are both involved with?
- Lateral opens (depresses) jaw, medial closes (elevates) it
- Both protrude the jaw and grind teeth
What are some of the bony landmarks of the infratemporal fossa?
- Articular tubercle of temporal bone
- Mandibular fossa of temporal bone
- Postglenoid tubercle of temporal bone
- Condyloid process of mandible
- Ramus and angle of mandible
- Coronoid process and mandibular notch
- Maxillary tuberosity and pyramidal process of palatine bone
- Pterygomaxillary fissure
- Foramen ovale and spinosum
- Spine of sphenoid
Which bony features form the TMJ?
- Articular tubercle of temporal bone (anterior limit)
- Mandibular fossa of temporal bone (receives head of mandible to create TMJ)
- Postglenoid tubercle of temporal bone (posterior limit of TMJ)
- Condyloid process of mandible
