INFRATEMPORAL FOSSA + CN V Flashcards
What structures can be found in the infratemporal fossa (muscles, vasculature and nerves)?
Temporalis and pterygoids are the muscles in ITF. The maxillary artery, pterygoid venous plexus, mandibular nerve, Chorda tympani and otic ganglion can be found here too.
What muscles are known for the elevation of the jaw?
What about the lowering of the jaw?
Mandible elevation: medial pterygoid, (vertical striations) masseter and temporalis;
The lateral pterygoid (with horizontal striations) lowers and protrudes the jaw.
What are the branches of the maxillary artery in 3 regions?
- Middle meningeal artery and Inferior Alveolar artery
- Arteries to mastication muscles
- Infraorbital and sphenopalatine arteries
Define the Chorda tympani nerve (origin, innervation and destination)
Originates from the facial nerve within the middle ear, emerges through the geniculate ganglion to supply pick up special sensation of taste to anterior 2/3 of tongue and supply preganglionic PSNS to the submandibular ganglion.
Where does the lingual nerve originate, what does it innervate and what other nerve does it run alongside on its way to the oral cavity?
Lingual nerve originates from mandibular division V3 of the trigeminal nerve which passed through the trigeminal ganglion in the MCF then into the ITF to course into the oral cavity. It supplies general sensation to the anterior 2/3 of the tongue.
Describe the pathway and innervation of the Lesser Petrosal Nerve.
The lesser petrosal nerve originates from the glossopharyngeal nerve (CN IX). It comes from the tympanic plexus of the middle ear and travels into the infratemporal fossa to synapse on the otic ganglion. After the otic ganglion it carries preganglionic PSNS fibers to the parotid gland.
Where does the Greater Petrosal nerve come from and what does it innervate?
The Greater Petrosal nerve comes from the Facial nerve (CN VII) and innervates the lacrimal glands
If a patient is not able to produce tears leading to a dry eye, he or she most likely injured his __________ gland. This is supplied by the ________ petrosal nerve which came form the pterygopalatine ganglion.
Lacrimal gland;
Greater petrosal nerve
If an oral surgeon is trying to apply a dental nerve block to a patient’s mouth before he performs a root canal, what nerve should he apply the anesthetic to?
Inferior alveolar nerve (a branch of the mandibular division V3)
Describe the location of the infratemporal fossa (ITF).
Located deep and medial to the mandible ramus. It is found inferior to the zygomatic arch and posterior to the maxilla.
What 3 muscles are responsible for elevating the jaw while chewing?
Masseter, Medial pterygoid and temporalis
What 2 muscles are responsible for depressing the mandibles when chewing?
Infrahyoids and Suprahyoids;
Gravity also plays a role in doing that naturally
What muscle can help protract mandible? What other function can it do?
Lateral pterygoid can protract and deviate the mandible away from its connection.
Describe what occurs at a fracture of the condylar process.
There is a deviation towards the injured side as the lateral pterygoid is injured. This is because of the “imbalanced” protrusion of the lateral pterygoid on the UNINJURED side.
What are the treatments for the dislocation of the TMJ “Subluxation” aka Locked Jaw Syndrome.
Lidocaine or pressing down on the mandible to realign the articular disc.
