Occlusion 2

Question 1

What are the components of occlusion

Answer 1

TMJ
Muscles of mastication
Teeth
Nerves
Muscles, ligaments, and bones which affect position of mandible

Question 2

When we describe occlusion as a tripod, what are the posterior and anterior apices?

Answer 2

Post = TMJs
Ant= teeth

Question 3

How is the human TMJ classified?

Answer 3

Bilateral synovial diarthrosis-ginglyoid joint

Question 4

The ____ is a fibrous extension of the capsule that runs between the ______ of the TMJ

Answer 4

Articular disc, two articular surfaces

Question 5

The articular disc of the TMJ articulates with the ______ above and the _____ below

Answer 5

Mandibular fossa of the temporal bone
Condyle of the mandible

Question 6

The articular disc is attached to the Condyle mesial and laterally by the ______
The anterior disc attaches to the ____ and the ______
The posterior portion attaches to the _____ and is called the _________

Answer 6

Collateral ligaments
Joint capsule, superior head of the lateral pterygoid
Mandibular fossa , retrodiscal tissue

Question 7

The capsule of the TMJ is a ______ that surrounds the join and attaches to the _____, ______, and __________

Answer 7

Fibrous membrane
Articular eminent, articular disc, and neck of the mand Condyle

Question 8

TMJ movement is limited by the _____ and the ______ of the _______

Answer 8

Fibrous capsule, boney limits, glenoid fossa (of temporal bone)

Question 9

Which part of the TMJ is vascular and highly innnervated?
Why is this significant?

Answer 9

Retrodiscal tissue
This is a major contributor of pain in Temporomandibular Disorder

Question 10

What is the transverse horizontal axis?
What is another name for this?
What is the significance of this?

Answer 10

An imaginary line around which the mandible may rotate within the sagittal plane
Hinge axis
This would be used as the starting point for full restorations where there is no other reference point; highly simplified concept of mand movement

Question 11

What are the principal muscles of mastication?

Answer 11

Four paired muscles:
Masseter
Temporalis
Medial pterygoid (internal)
Lateral pterygoid (external0

Question 12

what are the accessory muscles of mastication?

Answer 12

Buccinator
Digastric
Mylohyoid
Genihyoid

Question 13

Which muscles close the jaw or position it during closure?

Answer 13

Temporalis
Masseter
Medial pterygoid

Question 14

What are the actions of the Masseter muscles?

Answer 14

Elevation of the mandible
Protraction of the mandible ( by superficial fibers)
Retraction of the mandible (by deep fibers)

Question 15

What are the actions of the Temporalis muscles ?

Answer 15

Elevation of mandible
Retrusion (pull back) of mandible (by posterior fibers)

Question 16

If the TMJ was just a hinge joint, the closing muscles of the jaw would be opposed by the ____ muscles which pull the jaw down
But because of the sliding component, the opening of the jaw must be assisted by the _____ which pulls the _____ forward

Answer 16

Suprahyoid
Lateral pterygoid muscle
Condyle

Question 17

What are the actions of the medial pterygoid muscles?

Answer 17

Elevation of the mandible (closing mouth)
Protrusion of mandible (with/ lateral pterygoid)
Side to side movements of mandible (chewing)
*lateral and medial pterygoid muscles of two sides contract alternately

Question 18

What are the actions of lateral pterygoid muscles?

Answer 18

Depression of mandible (opening of mouth)
Protrusion of mandible (with/ medial pterygoid)
Side to side movements (chewing)
* lateral and medial of opp sides contract alternately

Question 19

Unilateral contraction of the_______ will produce a movement of the jaw _______

Answer 19

Lateral pterygoid
To the opposite side

Question 20

bilateral contraction of the _____ will produce a ________ of the jaw

Answer 20

Lateral pterygoids
Protrusion