Mandible, Maxilla and TMJ

Question 1

What is gliding?

Answer 1

When one bone moves across another without angular or rotational movement

Question 2

What is flexion?

Answer 2

Bending the joint so the bones forming it come towards one another.

Question 3

What is extension?

Answer 3

Straightening

Question 4

What is adduction?

Answer 4

To move a part of the body towards the midline of the body.

Question 5

What is abduction?

Answer 5

To move a part of the body away from the midline of the body.

Question 6

What is circumduction?

Answer 6

Circular movement

Question 7

What is medial rotation (a.k.a internal rotation)?

Answer 7

Rotation towards the centre of the body.

Question 8

What is lateral rotation (a.k.a external rotation)?

Answer 8

Rotation away from the centre of the body.

Question 9

What is protraction?

Answer 9

Anterior movement

Question 10

What is retraction?

Answer 10

Posterior movement.

Question 11

What is elevation?

Answer 11

To raise upwards

Question 12

What is depression?

Answer 12

To lower

Question 13

Movement of ball and socket joint?

Answer 13

Flexion, extension, abduction, adduction, circumduction and rotation

Question 14

Movement of hinge joint?

Answer 14

Flexion and extension

Question 15

Movement of gliding joint?

Answer 15

Sliding or gliding movement when one bone moves across the surface of another.

Question 16

Movement of a pivot joint?

Answer 16

Rotation

Question 17

Movement of saddle joint?

Answer 17

Flexion, extension, abduction, adduction, and circumduction.

Question 18

Movement of ellipsodial (a.k.a condylar) joint?

Answer 18

Flexion, extension, abduction, adduction, and circumduction (limited)

Question 19

What is the temporomandibular joint?

Answer 19

The articulation between the temporal bone and the mandible.

Question 20

Which structures form the articular surfaces of TMJ?

Answer 20

The condylar process of the ramus of the mandible and mandibular fossa of the temporal bone.

Question 21

How does the cartilage covering the articular surfaces of the TMJ differ from that of other joints?

Answer 21

It is fibrocartillage: a tough cartilage with dense bundles of fibres embedded in the matrix.

Question 22

List the attachments of the capsule of the TMJ

Answer 22

Superior attachment - the articular eminence and articular fossa of the temporal bone
Inferior attachment - the mandibular condyle and its neck

Question 23

What type of tissue is the articular disc made of ?

Answer 23

Usually composed of fibrocartillage, this enables them to absorb compression forces, adjust to changes in the contours of joint surfaces during movements and increase the range of movements that can occur.

Question 24

Where does the articular disc attach?

Answer 24

Lateral and medially to the mandibular condyle. Posteriorly, the upper division is attached to the temporal bone’s postglenoid process and lower division to the neck of the condyle.

Question 25

The capsule of the TMJ is strengthened laterally by a thick band of fibrous tissue. What is the name of this structure?

Answer 25

Temporal mandibular joint ligament (major)

Question 26

What two other accessory ligaments, besides from the TMJ joint ligament provide limited support to the TMJ?

Answer 26

The sphenomandibular ligament (minor) and the stylomandibular ligament (minor)

Question 27

What type of joint is the temporomandibular joint?

Answer 27

Modified hinge joint.

Question 28

What movement occur at TMJ?

Answer 28

In the lower compartment the mandibular condyle rotates on the the inferior surface of the articular disc. In the upper compartment a gliding movement occurs as the the superior surface of the articular disc slides down the articular eminence. This is known as translation.

Question 29

What are the functional movements of the jaw?

Answer 29

Depression, elevation, protraction, retraction and lateral deviation of the mandible.

Question 30

Which bones does the maxilla articulate?

Answer 30

Frontal bone (neurocranium), Temporal bone (neurocranium), Sphenoid bone (neurocranium), Ethmoid bone (neurocranium), Zygomatic bone (viscerocranium), Nasal bone (viscerocranium), Lacrimal bone (viscerocranium), Palatine bone (viscerocranium), Vomer (viscerocranium)