16. Infratemporal Fossa and Temporomandibular Joint (Wright) Flashcards
Nerve to the mylohyoid arises off of what other nerve?
Inferior alveolar N.
What muscles are responsible for depression of the jaw?
Suprahyoid muscles.
Infrahyoid muscles.
Lateral Pterygoid.
The “tensor” muscles of the face are innervated by which cranial nerve?
Trigeminal N.
What is the specific funciton of the stylomandibular and sphenomandibular Ls.?
The stylomandibular L. and the sphenomandibular L. specifically halt anterior dislocation of the mandible.
Identify the corresponding structures.
What muscles are responsible for the protraction of the jaw?
Masseter.
Lateral pterygoid.
Medial pterygoid.
What do the cell bodies of the otic ganglion ultimately serve?
The parotid gland.
What are the muscles of mastication?
Temporalis M..
Masseter M..
Lateral and Medial Pterygoid Ms.
What pulls the articular disc of the TMJ forward during wide jaw opening?
Superior head of the lateral pterygoid M.
What is the function of the buccal N. from the mandibular branch of the trigeminal?
What is the funciton of the buccal branch of the facial nerve?
Buccal nerve from V3 provides sensation to the interior cheek and part of the gums.
The buccal branch of the facial nerve provides motor innervation to the buccinator muscle.
What four ligaments hold the TMJ together?
Joint capsule
Sylomandibular L.
Sphenomandibular L.
Lateral temporomandibular L.
Where is the injection site for the anterior superior alveolar nerve?
Just at the exit of the infraorbital foramen. The infraorbital nerve must be blocked.
Where does the branchiomotor portion of the facial nerve exit the skull?
Through the stylomastoid foramen.
A fracture of the ramus of the mandible can damabe what structures?
Inferior alveolar artery and nerve.
What muscles are responsible for “retrusion” of the mandible?
Masseter M.
Temporalis M.
What foramen does the inferior alveolar N. enter?
The mandibular foramen.
What muscles are innervated by V3?
Muscles of mastication.
Mylohyoid M. and anterior belly of the digastric M.. (Nerve to mylohyoid.)
Tensor veli palatini M.
Tensor tympani M.
Nerve to the tensor tympani comes out of what structure?
The otic ganglion
What muscles are responsible for lateral movements of the jaw?
Lateral pterygoid M.
Temporalis M.
Masseter M.
What are the contents of the infratemporal fossa?
- inferior part of temporalis M.
- lateral and medial Pterygoid M.
- Maxilalry A.
- Pterygoid venous plexus
- INferior alveolar n (v3)
- lingual n (v3)
- Buccal n. (v3)
- Chorda Tympani (CN7)
- otic ganglion and glossopharyngeal n.
What are the boundaries of the infratemporal fossa?
What kind of fibers are carried in the lingual nerve?
Sensory nerve fibers. (Not taste, which is carried by the chorda tympani, which runs with the lingual nerve, but is not IN the lingual nerve.)
What muscles are responsible for elevation of the jaw?
Temporalis M.
Masseter M.
Medial pterygoid M.
What nerves supply the TMJ?
Auriculotemporal (posterior branch).
Masseteric N.
Where can we find the otic ganglion?
Posterior and inferior to V3 as it exits the foramen ovale.
Fracture high on the neck of the mandible can interfere with what structures?
Branches of the maxillary A. - such as deep auricular and anterior tympanic.
What are the accessory muscles of mastication?
What are they innervated by?
Buccinator M. and Orbicularis Oris M.
Facial Nerve (as muscles of facial expression).
Where are the injection sites for the posterior and middle superior alveolar nerve blocks?
By the molars for posterior, and by the premolars for middle.
Where is the injection site for the inferior posterior alveolar nerve?
Just inferior and lateral to the pterygomandibular raphe.
(The pterygomandibular raphe is the junction of the buccinator and the superior pharyngeal constrictor Ms.)
Important Foramen in the Temporal Fossa and Why?
Foramen Ovale
V3 passes through it
Fractures of the Mandible and related pathology
Fracture through neck of mandible-likely injure V3 or otic ganglion
Fracture of Ramus-injure inferior alveolar neurovasculature
Fracture of Corpus-Injure inferior alveolar n.
Massester M. Action and Innervation
elevates mandible
helps with protract/retract/side-side motions
Masseteric N. (V3)
Temporalis M. Action and Innervation
Elevate Mandible
helps with retraction and lateral movement
Deep Temporal N. (V3)
Lateral and Medial Pterygoid M. Action and Innervation
Lateral: Protrudes, opens, ipsilateral side to side/grinding
LAteral Pterygoid N. (V3)
Medial: Elevate, ipsilateral side-side movement
Medial Pterygoid N. (V3)
What muscles open the mandible by elevating hyoid?
Digastric (ant-nerve to mylohyoid, CN V, post. CN VII)
Geniohyoid (Ant. Ramus C1)
Mylohyoid (Mylohyoid N, V3)
Stylohyoid (CN VII)
these elevate/draw forward the hyoid bone
What opens the mandible by fixing/drawing down the hyoid?
Sternohyoid (ansa cervicalis)
Sternothyroid (ansa cervicalis)
Thyrohyoid (Ant. ramus C1 & 4)
Omohyoid (Ansa cervicalis)
Depress/fix hyoid and larynx during swallowing
These ligaments limit inferior excursion at the TMJ
sphenomandibular L.
Stylomandibular L.
Superior head of the lateral pterygoid attaches to what unique feature of the TMJ
articular disc and helps move the disc when opening the jaw
What is the function of the posterior and anterior bands of the articular disc?
helps keep the articular disc in place
Note that the TMJ essentially anterior dislocates every time the jaw is open to an angle greater than 15’
