Infratemporal And Pterygopalatine Fossae Flashcards
What is the infratemporal fossae?
• It is the space inferior to the temporal fossa
• Complex space that serves as the gateway for neurovascular structures between
– cranial cavity and oral cavity
– cranial cavity and nasal cavity
What is contained within the infratemporal fossae?
• Contains – Lateral & medial pterygoid muscles – Temporalis muscle – Maxillary artery – Pterygoid venous plexus – Mandibular division of the trigeminal nerve – Chorda tympani nerve – Otic ganglion
What make up the roof of the infratemporal fossa?
– Greater wing of sphenoid
– Temporal bone
• Foramen ovale (CNV3) and spinosum (middle
meningeal artery)
What make up the lateral wall of the infratemporal fossa?
• Lateral wall
– Ramus of mandible
• Mandibular Foramen
What make up the anterior wall of the infratemporal wall?
• Anterior wall
Maxilla
What forms the posterior wall of the infratemporal fossa?
Posterior wall
Styloid process Mastoid process Stylomastoid foramen
(CNVII)
What forms the medial wall of the infratemporal fossa?
Pterygomaxillary fissure
(gateway to PT fossa)
Lateral pterygoid plate
What is the classification of the temporomandibular joint?
Classification
– Atypical synovial joint
– Modified hinge/ condylar
What are the Articular surfaces of the tempo mandibular joint?
• Articular surfaces: – Condyle of the mandible – Articular tubercle of temporal bone (anteriorly) – Mandibular fossa
What nerve innervates the temporomandibular joint?
Innervation
– Auriculotemporal nerve
What’s the special feature of the temporomandibular joint?
Special feature
– Articular disc, helps glide over the articular tubercle when opening mouth
What is special about the temporomandibular joint Articular surface?
- Articular surfaces not covered with hyaline cartilage
- Fibrocartilage resembling epiphyseal plate
- Withstand shear and compression forces
Contrast the location and function of the lateral and medial pterygoid?
Lateral pterygoid
Lateral pterygoid plate Mandibular neck Depression and protrusion
Medial pterygoid
Lateral pterygoid plate
Internal aspect of the mandibular angle
Elevation
What are the muscles of mastication?
Temporalis
Lateral pterygoid
Masseter
Medial pterygoid
Where does the temporalis insert? What it’s movement?
Temporalis
Temporal fossa, mandibular head and neck
Elevation and retrusion
What are the insertions of the lateral pterygoid? What’s its function?
Lateral pterygoid
Lateral pterygoid plate, mandibular neck
Depression and protrusion
What are the insertions of the masseter? What’s the function and movements of the masseter?
Masseter
Angle of mandible, zygomatic arch
Elevation, protrusion, retrusion
What’s the insertions and functions of the medial pterygoid?
Medial pterygoid
Lateral pterygoid plate, internal aspect of the mandibular angle
Elevation
What muscles are responsible for depression ?
Gravity
Digastric, geniohyoid, and mylohyoid
What muscles are responsible for elevation?
Temporalis, masseter, medial pterygoid
What muscles are responsible for retraction?
Posterior fibers of Temporalis, deep part of masseter and geniohyoid and digastric
What muscles are responsible for protrusion ?
Lateral pterygoid assisted by medial pterygoid
What is the terminal branch of the external carotid? What does it supply?
Maxillary artery
- Terminal branch of the external carotid artery
- Supplies the deeper structures of the face
- Branches are arranged mainly around the lateral pterygoid muscl
What are the 3 parts of the maxillary artery?
- 1st part gives branches that enter foramina
- 2nd part supply muscles
- 3rd part gives branches that enter foramina
What does sphenopalatine a. Supply?
Passes through the sphenopalatine Foramen
Supplies the nasal cavity
What does the infraorbital artery supply?
Passes through Infraorbital foramen
Maxillary sinus Face inferior to the eye
What does posterior superior alveolar supply?
Supplies upper teeth
What does descending palatine artery supply?
Divides into lesser and greater palatine
What two arteries anastomose in the incisive Foramen?
Descending palatine and sphenopalatine
anastomose through the incisive Foramen
What are the important inter veinous connections?
There are extensive connections between the cavernous sinus and;
– the veins of the face
– pterygoid plexus of veins in the infratemporal fossa
• Since these veins have no valves, infections and/or thrombi may easily travel to the cavernous sinus through any of these channels
• Deep facial vein joins the pterygoid plexus
• Maxillary vein continues from the pterygoid plexus
• Angular vein becomes the facial vein and joins with the labial veins
• Both the facial and maxillary veins drain into the retromandibular
What is the danger area of the face?
Facial vein connections with deeper veins
- To cavernous sinus by superior ophthalmic veins (angular vein)
- To pterygoid venous plexus by deep facial vein and then to cavernous sinus through inf ophthalmic or emissary veins
- Valveless connections
• Infections in the danger area of the face can very easily be
disseminated intracranially
Where is the pterygopalayine fossa
- Located “inside” the infratemporal fossa
- Serves as a gateway to the nasal apparatus
- Containsthepterygopalatineganglion/hayfever ganglion
What are the walls of the pterygopalatine fossa?
– Roof: body of sphenoid
– Medial: perpendicular plate of the palatine bone
– Anterior: posterior wall of maxilla
– Posterior: sphenoid
What are the contents of the pterygopalatine fossa?
– Maxillary artery
(pterygomaxillary fissure)
– Maxillary nerve (Foramen rotundum)
– Pterygopalatine ganglion
What are the nerves associated with the pterygopalatine fossa?
- V2 – Maxillary nerve (sensory) – enter via foramen rotundum
- Infraorbital nerve (sensory, sympathetic) – exit into inferior orbital fissure as continuation of the maxillary•Nerve of the pterygoid canal (sympathetic and
parasympathetic)
– enter via the pterygoid canal the
combination of;
– Greater petrosal nerve (preganglionic parasympathetic)
– Deep petrosal nerve (postganglionic sympathetic)
• Zygomatic nerve (sensory, sympathetic and parasympathetic
postganglionic)
• Superior alveolar (sensory, parasympathetic postganglionic
