Temporal, Infratemporal and Submandibular Regions, and the Temporomandibular joint Flashcards
State the boundaries of the temporal fossa.
Anterior: Zygomatic and frontal bones
Posterior: Inferior temporal line and supramastoid crest
Superior: Superior temporal line
Inferior: Zygomatic arch
Floor: Parts of frontal, parietal and temporal bones and greater wing of sphenoid bone
What forms the zygomatic arch?
Anteriorly by the temporal process of zygomatic bone
Posteriorly by the zygomatic process/zygoma of temporal bone
[Diagram]
List the contents of the temporal fossa.
- Temporalis muscle
- Temporal fascia (overlies the temporalis muscle)
- Superficial temporal artery [one of the terminal branch of ________________ artery]
- Superficial temporal vein [unites with maxillary vein to form the ________________ vein]
- Auriculotemporal nerve [branch of mandibular nerve]
- Zygomaticotemporal nerve
- Temporal branch of facial nerve
- [Diagram]
State the clinical relevance of temporal fossa.
Temporalis flap
List the boundaries of the infratemporal fossa.
Laterally (superficial): ramus of the mandible
Medially (deep): lateral pterygoid plate
Anteriorly: posterior aspect of the maxilla
Posteriorly: tympanic plate, mastoid and styloid processes of the temporal bone
Superiorly: the inferior (infratemporal) surface of the greater wing of sphenoid [Notice the infratemporal crest on the infratemporal surface of greater wing of sphenoid]
State the contents of the infratemporal fossa.
- Inferior part of the temporalis muscle
- Lateral and medial pterygoid muscles
- Maxillary artery
- Pterygoid venous plexus
- Mandibular, inferior alveolar, lingual, buccal, chorda tympani nerves
- Otic ganglion
- [Diagram: Some of the contents of infratemporal fossa]
The medial and lateral plates of pterygoid process are parts of the ________________ bone.
sphenoid
[Diagram]
List the muscles of mastication.
- Medial pterygoid muscle
- Lateral pterygoid muscle
- Masseter
- Temporalis
- [Diagram]
Medial pterygoid muscle
1. Origin
2. Insertion
3. Innervation
4. Action
-
Origin:
Deep head—medial surface of lateral plate of pterygoid process and pyramidal process of palatine bone
Superficial head—tuberosity of the maxilla and pyramidal process of palatine bone - Insertion: Medial surface of mandible near angle
- Innervation: Nerve to medial pterygoid from the mandibular nerve [V3]
- Action: Elevation and side-to-side movements of the mandible. It can assist in protrusion of mandible, but that is a weak action of medial pterygoid.
- [Diagram 1] [Diagram 2]
Side-to-side movement is done during chewing.
Lateral pterygoid muscle
1. Origin
2. Insertion
3. Innervation
4. Action
-
Origin:
Upper head—roof of infratemporal fossa
Lower head—lateral surface of lateral plate of the pterygoid process - Insertion: Capsule of temporomandibular joint in the region of attachment to the articular disc and to the pterygoid fovea on the neck of mandible
- Innervation: Nerve to lateral pterygoid directly from the anterior division of the mandibular nerve [V3] or from the buccal branch
- Action: Protrusion, side-to-side movements and depression of the mandible
- [Diagram 1] [Diagram 2]
Further notes:
✓ Side-to-side movement is done during chewing.
✓ Among all the four muscles of mastication (medial pterygoid, lateral pterygoid, masseter, and temporalis), the lateral pterygoid is the only muscle that participates in depressing the mandible.
Masseter
1. Origin
2. Insertion
3. Innervation
4. Action
- Origin: Zygomatic arch and maxillary process of the zygomatic bone
- Insertion: Lateral surface of ramus of mandible
- Innervation: Masseteric nerve from the anterior division of the mandibular nerve [V3]
- Action: Elevation of mandible
- [Diagram: Masseter]
Temporalis
1. Origin
2. Insertion
3. Innervation
4. Action
- Origin: Bone of temporal fossa and temporal fascia
- Insertion: Coronoid process of mandible and anterior margin of ramus of mandible almost to last molar tooth
- Innervation: Deep temporal nerves from the anterior division of the mandibular nerve [V3]
- Action: Elevation and retraction of mandible
- [Diagram: Temporalis]
a) What type of joint is the temporomandibular joint (TMJ)?
b) Articular surfaces of the TMJ?
a) (Compound) Condylar synovial joint
b) Superiorly: mandibular fossa and articular tubercle.
Inferiorly: head of the mandible.
[Diagram: TMJ] [Diagram: Mandible]
Note: The articular tubercle prevents dislocation.