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  1. What type of joint is TMJ
    • Modified codyloid:
    • has condyle
    • has fossa
    • can move on two axis, plus some extra movement (modified)
    • loose capsule --> more mobile
  2. TMJ Capsule
    Runs from temporal bone to neck of mandible
  3. Anterior and posterior tuburcles
    Prevent too much movement forward and backwards
  4. Type of cartilage over articular surface
    fibrocartilage (different than most joints (usually hyalin)) --> stronger joint
  5. Sphenomandibular ligament
    • Attachments: medial surface of ramus up to spine of sphenoid
    • Functions: checks angle of mandible so it doesn't move too much - allows jaw to rotate instead of dropping down and forward; suspends mandible
  6. Stylomandibular ligament
    • Attachments: styloid process down to angle of mandible
    • Functions: guides mandible;
  7. Temporomandibular/lateral ligament
    • Attachments: temporal bone down to neck of mandible
    • Thickening of joint capsule
    • Functions: prevents excessive lateral excursion and posterior displacement (along with posterior tubercle)
  8. Articular Disc
    • fibrocartilage
    • lacks blood supply
    • allows jaw to move more freely
    • attachment for lateral pterygoids
    • with full opening of jaw, lateral excursion, protrusion and retrusion: articular disc drops down out of fossa
  9. Masseter
    • Origin: Anterior and posterior zygomatic arch
    • Insertion: Angle and lateral ramus of mandible
    • Innervation: CN V3
    • Main Action: Elevates and protrudes mandible; deep fibers retrude mandible
  10. Temporalis
    • Origin: Temporal fossa
    • Insertion: Ramus of mandible and coronoid process
    • Innervation: CN V3
    • Main Actions: Elevates mandible; posterior fibers retrude mandible
  11. Lateral Pterygoid
    • Origin: Greater wing of sphenoid, lateral pterygoid plate
    • Insertion: neck of mandible, articular disc, and capsule of TMJ
    • Innervation: CN V3
    • Main Actions: Acting together, protrude mandible and depress chin; acting alone and alternately, produces side-to-side movements
  12. Medial Pterygoid
    • Origin: Medial surface of lateral pterygoid plate
    • Insertion: Medial surface of mandible near angle
    • Innervation: CN V3
    • Main Actions: Elevates mandible; acting together, protrude mandible; acting alone, protrudes side of jaw; acting alternately, produces grinding motion
  13. Muscles that open jaw
    • digastric
    • lateral pterygoid
  14. Muscles the close jaw
    • masseter
    • temporalis
    • medial pterygoid
  15. Muscles of protrusion
    • masseter
    • medial pterygoid
  16. Muscles of retrusion
    • temporalis
    • digastric
  17. Muscles of lateral excursion
    • same side:
    • temporalis
    • opposite side:
    • medial pterygoid
Card Set:
2012-02-08 05:59:46

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