Temporal And Infratemporal Fossae Flashcards
What are the boundaries of the Temporal Fossa?
Superior: Superior temporal line
Inferior: Zygomatic arch
Anterior: Zygomatic bone and its frontal process
Posterior: Posterior part of the superior temporal line and supramastoid crest
Roof/Lateral: Temporalis fascia
Floor/Medial: Bones of the pterion
What are the contents of the Temporal Fossa?
Temporalis muscle
Superficial temporal vessels
Middle temporal artery
Deep temporal branches of the maxillary artery
Auriculotemporal nerve
Deep temporal nerves
Temporal and zygomatic branches of the facial nerve
What is the function of the Temporalis muscle?
Anterior fibers: Elevation of the mandible
Posterior fibers: Retraction of the mandible
What bones form the Pterion?
Frontal bone
Squamous Temporal bone (ST)
Parietal bone
Greater Wing of Sphenoid (GWS)
What are the boundaries of the Infratemporal Fossa?
Lateral Wall: Ramus of the mandible with overlying masseter muscle
Medial Wall: Pterygomaxillary fissure, lateral pterygoid plate, tensor and levator veli palatini muscles, superior constrictor muscle
Anterior Wall: Posterior wall of the maxilla (maxillary air sinus)
Posterior Wall: Styloid process (SP) and carotid sheath
Roof: Infratemporal surface of the greater wing of the sphenoid and adjacent part of the squamous temporal bone
What is the clinical significance of the Pterion?
Depressed fractures of the pterion can cause bleeding from the anterior branch of the middle meningeal artery, leading to an extradural/epidural hemorrhage.
What are the functions of the Lateral Pterygoid muscle?
Protraction of the mandible
Innervation: Mandibular nerve
What are the functions of the Medial Pterygoid muscle?
Elevation of the mandible (in combination with temporalis and masseter)
Protraction of the mandible (with bilateral contraction of lateral pterygoid muscles)
Movement to the opposite side (with contraction of one muscle and ipsilateral lateral pterygoid)
What are the branches of the Maxillary artery in the Infratemporal Fossa?
Deep temporal
Middle meningeal
Accessory meningeal
Inferior alveolar
Posterior superior alveolar
Infraorbital
What is the clinical significance of the Pterygoid plexus of veins?
It is connected to the cavernous sinus via emissary veins, inferior ophthalmic veins, and deep facial veins.
Cavernous sinus thrombosis can occur, leading to severe headaches, swelling around the eyes, and vision loss.
What are the branches of the Mandibular nerve in the Infratemporal Fossa?
From main trunk: Nervus spinosus, nerve to medial pterygoid, branches to tensor veli palatini and tensor tympani
From anterior division: Deep temporal nerves, masseteric nerve, nerve to lateral pterygoid, buccal nerve (sensory)
From posterior division: Auriculotemporal, inferior alveolar, nerve to mylohyoid, lingual nerve
What is the function of the Auriculotemporal nerve?
Supplies parts of the auricle, external acoustic meatus, outer surface of the tympanic membrane, and skin of the temple.
Contains postganglionic parasympathetic secretomotor fibers from the otic ganglion to the parotid gland.
What is Frey’s Syndrome?
A condition that follows parotid surgery where damaged parasympathetic fibers reorganize and supply sweat glands, causing the parotid region to sweat and flush when food is seen.
What is the clinical significance of the Lingual nerve?
It may be damaged during the extraction of the 3rd lower molar tooth.
It carries sensation from the anterior 2/3 of the tongue, floor of the mouth, and mandibular gums.
What is the function of the Chorda Tympani nerve?
Carries preganglionic secretomotor fibers to the submandibular ganglion.
Carries taste fibers from the anterior 2/3 of the tongue.
What is the clinical relevance of the Temporomandibular (T-M) Joint Dislocation?
The mandibular head is located in front of the articular eminence, causing trismus (inability to open the mouth completely).
Reduction is achieved by depressing the mandible and pushing it backward.
Why is the lingual nerve at risk during dental procedures, and what are the consequences of its damage?
The lingual nerve is at risk during the extraction of the lower third molar (wisdom tooth). Damage can result in loss of sensation to the anterior 2/3 of the tongue, floor of the mouth, and mandibular gums, as well as affect taste sensation due to involvement of the chorda tympani.
How is the infratemporal region connected to intracranial structures, and why is this clinically significant?
The pterygoid plexus of veins in the infratemporal region is connected to the cavernous sinus via emissary veins. Infections or thrombophlebitis in this region can spread to the cavernous sinus, causing cavernous sinus thrombosis, a serious condition with symptoms like severe headache, vision loss, and eye movement disorders.
What muscles are innervated by the nerve to the medial pterygoid?
The nerve to the medial pterygoid also supplies the tensor veli palatini (involved in soft palate function) and tensor tympani (involved in middle ear function).
What are the functions of the Tensor Tympani and Tensor Veli Palatini muscles?
Tensor Tympani: Involved in hearing by dampening sounds in the middle ear.
Tensor Veli Palatini: Involved in swallowing by tensing the soft palate.
