What's this? What does it connect?
connects styloid process and mandibular angle
What is this?
What does it connect?
connects spine of sphenoid to lingula of mandible (inner/medial surface of mandibular ramus)
What is this? What does it connect?
- zygomatic arch to condylar process of mandible
What are the movements of the TMJ?
- raising and lowering jaw
- protrusion and retraction
- side-to-side movement (grinding)
- combined movements = chewing
What is the axis of the TMJ?
Why is the location of its axis significant?
- a transverse axis through the mandibular lingula
- the lingula is a site of entry for a nerve into the mandible and since no movement happens at the axis, this is a safe place for it
What kind of joint is the TMJ?
Condyloid Synovial Joint
(ginglymus = hinge
arthrodial = sliding)
The jaw opens via two movements of the TMJ.
What are they?
How much opening does each movement result in?
Hinge-like rotation - opens the first 20 mm or so
Forward/downward translation/gliding - the next 20-30 mm
What lines the head of the mandible and the mandibular fossa?
What is the articular disc of the TMJ made of?
What are the two separate joints of the TMJ called?
discotemporal - btwn disc and mandibular fossa, responsible for translational gliding
discomandibular - btwn disc and head of mandible, responsible for hinge-like rotation
What are the muscles of mastication?
- medial pterygoid
- lateral pterygoid
- runs from greater wing of sphenoid + pterygoid plate to condyloid process of mandible
- opens mouth/depresses mandible
- protrudes and moves mandible side-to-side
- lateral pterygoid plate, pyramidal process of palatine + maxillary tuberosity > medial mandibular angle
- elevates mandible
- helps lateral pterygoid with grinding
- zygomatic arch (deep) + maxilla (superficial) > coronoid process/ramus of mandible
- closes/elevates mandible
- protracts jaw
- temporal lines > coronoid process of mandible
- elevates mandible
- retracts mandible
What innervates all the muscles of mastication?
3rd division of the trigeminal nerve (CN V) known as the mandibular nerve
Name the numbers.
4 and 6 are the two separate joints