Temporal and Infratemporal Fossae - 17 Flashcards
Bony Landmarks of the Mandible
Ramus, Angle, Body
Temporal Lines
Superior: attachment of temporalis fascia
Inferior: attachment of temporalis muscle
Temporal Boundaries
Superior/Posterior: inferior temporal line
Anterior: frontal process of zygomatic
Inferior: zygomatic arch
Temporal Floor Contents
Floor:
- greater wing of sphenoid
- squamous temporal
- frontal
- parietal
Contents:
- temporalis muscle
- deep temporal nerve and arteries
- zygomaticofacial nerve
Muscles of Mastication
Innervated by mandibular branch of CN V
Masseter, temporalis, lateral pterygoid, medial pterygoid
Masseter
O: inferior margin of deep surface of zygomatic bone
I: lateral surface of mandibular ramus and coronoid process
In: CN V
F: Elevates and protracts mandible
Temporalis
O: floor of temporal fossa and temporal fascia
I: coronoid process and anterior border of mandibular ramus
In: CN V
F: elevates and retracts mandible
Lateral Pterygoid
O: lateral pterygoid plate and greater wing of sphenoid
I: front of neck of mandible, articular disc and TMJ
In: CNV
F: protracts mandible, depresses chin (bilateral); grinding (unilateral)
Medial Pterygoid
O: lateral pterygoid plate and maxilla
I: medial surface of mandible near angle
In: CN V
F: elevates, protracts (Bilateral); grinding (unilateral)
Temporomandibular Joint (TMJ)
Between head of mandible (condyloid process) and mandibular fossa of temporal bone
Intervening fibrocartilage disc:
•Divides joint into superior and inferior compartments.
•Allows mandible to protract and retract as well as elevate and depress.
Axes
Anterior Gliding and Hinge-like rotation
Anterior gliding of TMJ
Protraction and retraction; grinding occurs when protraction and retraction of the mandible alternate on the two sides.
Hinge-Like Rotation of TMJ
During mandibular depression, head of the mandible and the articular disc move anteriorly until the head lies inferior to the anterior tubercle.
TMJ Ligaments
Temporomandibular, Sytlomandibular, Sphenomandibular
Temporomandibular Ligament
Base of zygomatic process to mandibular neck
Stylomandibular Ligament
- Styloid process to angle of mandible
* Runs between parotid and submandibular glands
Sphenomandibular Ligament
- Sphenoid spine to mandibular lingula
- Lies medial to TMJ
- Remnant of Meckel’s cartilage
Infratemporal Fossa
Communicates with orbit via inferior orbital fissure and with the pterygopalatine fossa via the pterygomaxillaryfissure.
Contents of the Infratemporal Fossa
- Mandibular nerve
- Maxillary artery
- Medial and lateral pterygoid muscles
- Lower part of temporalis muscle
- Chorda tympani nerve
- Otic ganglion
Borders of the Infratemporal Fossa
- Anterior
- Superior
- Medial
- Lateral
- Inferior
- Posterior
- Maxilla
- greater wing of sphenoid
- lateral pterygoid plate
- coronoid process and ramus of mandible
- contiuous with neck
- TMJ and styloid process
Maxillary Artery (4)
- Terminal branch of external carotid artery
- Crosses infratemporal fossa and enters the pterygopalatine fossa via the pterygomaxillary fissure.
- Divided into three parts by lateral pterygoid muscle:
- Artery may pass superficial or deep to muscle
First Branch of MA
Origin from external carotid artery to lower margin inferior to lateral pterygoid
- Deep Auricular
- Anterior Tympanic
- Middle Meningeal
- Accessory Meningeal
- Inferior Alveolar
Second Branch of MA
Superficial or deep to inferior lateral pterygoid
Branches to muscles of mastication
Buccal artery
Third Branch of MA
Lies within pterygopalatine fossa
- descending palatine
- artery to pterygoid canal
- pharyngeal artery
- sphenopalatine artery
- infraorbital
- posterior superior alveolar
