Jaw muscles Flashcards
What kind of joint is the temporomandibular joint?
Synovial hinge joint
The temporomandibular joint is formed by articulations between what?
Mandibular fossa & articular tubercle of temporal bone & condylar process of mandible
What movements does the temporomandibular permit?
- gliding
- rotation
- flexion
- extension
What is the articular disc and what does it do in the temporomandibular joint?
Separate the 2 articular surfaces and creates a sup & inf articular cavity
What thickens the TMJ capsule laterally?
Lateral ligament of TMJ
Which bony structure acts with the lateral ligament to prevent TMJ dislocation?
Mastoid process
Other than the lateral ligament of the TMJ what 2 other ligaments support the joint and what are their attachments?
SPHENOMANDIBULAR LIGAMENT - med to TMJ. From spine of sphenoid bone to lingula on med ramus of mandible
STYLOMADIBULAR LIGAMENT - from styloid process of temporal bone tok post margin of angle of mandible
What must happen in the TMJ in order for the mouth to open?
Condylar process of mandible glides ant to lie beneath articular tubercle
Depression of the mandible (opening the mouth) is only possible when what?
Mandible condyle is fully protracted (beneath articular process)
What movement is essential to grind between molars?
Protrusion of condylar process and depression of mandible
Which muscles contribute to depression of the mandible or opening of the mouth against resistance?
Lateral pterygoid & hyoid muscles
What are the 4 principle muscles of mastication?
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Elevation of the mandible requires the action of what 3 muscles of mastication?
Masseter
Temporalis
Medial pterygoid
Depression of the mandible requires the action of what 3 muscles of mastication?
Lateral pterygoid
Hyoid muscles
Protrusion of the mandible requires the action of which muscle of mastication?
Lateral pterygoid
