Deep Face Flashcards
What is the pterion?
The H-shaped suture formed by the meeting of the parietal, frontal, sphenoid (greater wing) and temporal bones.
Why is the region of the pterion sensitive?
The middle meningeal artery runs deep to the pterion. Any injury to this artery can result in an epidural hematoma.
What is the weakest part of the skull?
The pterion.
Name the insertion of the temporalis.
Ramus of the mandible and coronoid process
Name the origin of the temporalis muscle.
Inferior temporal line and temporal fossa
What innervates the temporalis?
Mandibular division of the trigeminal nerve (V3) - anterior and posterior deep temporal nerves
What is the function of the temporalis?
Closes (elevates) and retracts the jaw
Blood supply of the temporalis?
Superficial temporal and maxillary arteries
Name the origin of the masseter.
The zygomatic arch
Name the insertion of the masseter.
Ramus of the mandible and coronoid process
What innervates the masseter?
Mandibular division of the trigeminal nerve (V3) - nerve to the masseter
Name the action of the masseter.
Powerfully closes (elevates) and retraction, and limited protraction of the jaw
What is the blood supply to the masseter?
Transverse facial artery
What are the most important features of the infratemporal fossa?
- Foramen Ovale (V3 entry)
- Foramen spinosum (middle meningeal artery enters)
- Petrotympanic fissure (chorda tympani enters)
- Opening to the mandibular canal (inferior alveolar nerve)
- Pterygomaxillary Fissure
What are the contents of the infratemporal fossa?
- The medial and lateral pterygoid muscles
- The maxillary artery and its branches
- The mandibular division of the trigeminal nerve [CN V3] and its branches
- Sensory and motor branches of the facial nerve [CN VII] - chorda tympani;
- Branches of the glossopharyngeal nerve [CN IX] which synapse in the otic ganglion (parasympathetics for parotid gland from CN IX)
Name the origins of the 2 heads of the Medial Pterygoid.
Medial head: medial surface of the lateral pterygoid plate.
Lateral head: lateral surface of the lateral pterygoid plate
Name the insertion of the medial pterygoid.
Medial surface of the mandible near the angle
What is the innervation of the medial pterygoid?
Mandibular division of the trigeminal nerve (V3) - nerve to the medial pterygoid
What is the function of the medial pterygoid?
Elevates and protracts the mandible; allows side-to-side motion; grinds food
Blood supply of the medial pterygoid?
Facial and maxillary arteries
Name the origins of the 2 heads of the Lateral Pterygoid.
Superior head: infratemporal crest
Inferior head: lateral surface of the lateral pterygoid plate
Name the insertion of the 2 heads of the Lateral Pterygoid.
TMJ and mandible
Name the innervation of the lateral pterygoid.
Mandibular division of the trigeminal nerve (V3)
What is the action of the lateral pterygoid?
*LateralLowers Lowers/opens and protracts the jaw; grinds food. Gravity also opens the jaw.
Describe motion of the jaw to the left using the medial and lateral pterygoids, and masseter.
To move the jaw to the left, contract the right medial and lateral pterygoids and left masseter.
Describe motion of the jaw to the right using the medial and lateral pterygoids, and masseter.
To move the jaw to the right, contract the left medial and lateral pterygoids and right masseter.
Name the nerves of the temporomandibular joint.
Facial nerve – as it travels toward its entrance into the parotid gland
Auriculotemporal nerve – sends branches to the TMJ. Any irritation/Inflammation from TMJ dysfunction can cause referred pain to other regions supplied by this nerve
What nerves pass between the Lateral Pterygoid and Medial Pterygoid muscles?
The lingual and inferior alveolar nerves pass between these 2 muscles.
How can dysfunction of the TMJ affect the lingual and inferior alveolar nerves?
Dysfunction of the TMJ may contribute to spasm within the medial and lateral pterygoids, which can cause low grade pressure on the lingual and; inferior alveolar nerves. This leads to abnormal sensation in the jaw and oral cavity.
Describe the 1st movement of the TMJ.
1st movement (lower compartment): Rotational hinge movement that results in opening the jaw (1 finger breadth).
Describe the 1st movement of the TMJ.
2nd movement (upper compartment): Can only occur AFTER the 1st hinge movement has completed. 2nd movement is a sliding/gliding movement leading to full opening (3 fingers breadth) and protrusion (sliding forward) of the mandible. The articular disc moves with the head of mandible.
What are the branches and functions of the mandibular part of the maxillary artery?
Middle meningeal artery - enters the foramen spinosum to supply the dura mater and internal skull
inferior alveolar artery - enters the mandibular foramen to supply the teeth; exits the mental foramen as the mental artery
What are the branches and functions of the pterygoid part of the maxillary artery?
Anterior and Posterior deep temporal arteries - supply the temporalis muscle
Buccal artery - supplies the cheek and buccinator
What are the branches and functions of the pterygomaxillary part of the maxillary artery?
Infraorbital artery - passes through the inferior orbital fissure to supply the face
Posterior superior alveolar - passes through the pterygomaxillary fissure to supply the posterior molar
Sphenopalatine artery - passes through the sphenopalatine foramen to the nasal cavity
What are the branches and functions of the anterior division of the mandibular branch of the trigeminal nerve?
Anterior Division (Primarily) Motor
Anterior and Posterior Deep Temporal Nerves
Nerve to the Masseter
Nerve to the Medial and Lateral Pterygoids
Long Buccal Nerve - SENSORY!!! to the cheek
What are the branches of the posterior division of the mandibular branch of the trigeminal nerve?
Posterior Division (Primarily) Sensory
Auriculotemporal Nerve
Inferior Alveolar Nerve - nerve to the mylohyoid and mental nerve
Lingual nerve - chorda tympani joins
Describe route and function of the Auriculotemporal Nerve.
Sensory to the inner ear. Splits around the middle meningeal artery, rejoins, and passes through the parotid.
What is GLOAP?
GLOAP = parasympathetic function of CN IX - The glossopharyngeal nerve has a branch called the Lesser petrossal, which synapses in the otic ganglion. Postganglionics jump onto the auriculotemporal branch of CN V to head over to the parotid.
Describe route and function of the inferior alveolar Nerve.
The inferior alveolar nerve gives off the nerve to the mylohyoid, then passes through the mandibular foramen to provide sensory innervation to the lower teeth. It then exits the mental foramen as the mental nerve.
Describe route and function of the nerve to the mylohyoid.
The nerve to the mylohyoid provides MOTOR innervation to the anterior belly of the digastric and the mylohyoid. (5 AM)
Describe route and function of the lingual nerve.
The lingual nerve provides sensory innervation to the anterior 2/3 of the tongue.
Describe route and function of the chorda tympani.
The chorda tympani supplies the SVA innervation for taste to the anterior 2/3 of the tongue.
Chorda tympani fibers traveling in the lingual nerve also carry preganglionic parasympathetics (GVE) to the submandibular ganglion to synapse.
Postganglionic fibers from the submandibular ganglion provide the secretomotor innervation to the submandibular and sublingual glands.
