TMJ

Question 1

What innervates pain in the TMJ?

Answer 1

free nerve endings

Question 2

What innervates static mechanoreception in the TMJ?

Answer 2

golgi tendon organs

Question 3

What innervates dynamic mechnoreception in the TMJ?

Answer 3

pacinian corpuscles

Question 4

What innervates proprioception in the TMJ?

Answer 4

ruffini corpuscles

Question 5

The TMJ is classified as what type of joint?

Answer 5

a synovial sliding-ginglymoid
(hinged)

Question 6

Synovial joints permit movement between ____ bones

Answer 6

two

Question 7

Each bone in the TMJ is covered by what kind of cartilage?

Answer 7

hyaline

Question 8

Where is the synovial fluid derived from?

Answer 8

villus cells

Question 9

Both the condylar neck and head develop by _________ ossification.

Answer 9

endochondral

Question 10

How is the growth of the TMJ different from long bones in the body?

Answer 10

• multidirectional growth capacity
• cartilage cells in the condylar head and neck do not exhibit ordered columns

Question 11

Bones of the TMJ are the…

Answer 11

glenoid fossa and the mandibular condyle

Question 12

What does the superior head of the lateral pterygoid muscle attach to?

Answer 12

joint capsule and articular disc

Question 13

What does the inferior head of the lateral pterygoid muscle attach to?

Answer 13

condylar neck in the pterygoid fovea

Question 14

The articulating surfaces are covered with a layer of…

Answer 14

fibrous tissue

Question 15

With increasing age, the deeper portions of the fibrous covering of the TMJ may exhibit islands of _______

Answer 15

cartilage

Question 16

Answer 16

condylar head of child

Question 17

Answer 17

Condylar head of adult

Question 18

Answer 18

articular disc of young adult

Question 19

Answer 19

articular disc of elderly adult

Question 20

What is the retrodiscal connective tissue (bilaminar zone) made of?

Answer 20

collagen and elastic fibrous connective tissue, fat cells, and is highly vascular

Question 21

What do the elastic fibers of the bilaminar zone of the TMJ insert into?

Answer 21

petrotympanic fissure

Question 22

Answer 22

Retrodiscal Connective Tissue (a.k.a. bilaminar zone)

Question 23

The TMJ synovial membrane consists of what layers?

Answer 23

• fibrous capsule
• vascular subintima
• intimal layer

Question 24

What does anterior dislocation of the disc do to the position of TMJ?

Answer 24

The disc is attached to the medial and lateral surfaces of the condyle, but not the temporal bone. Thus, when the mandible moves, the disc moves as well, traveling over the anterior surface of the articular fossa.

Question 25

What two cell type are in the intimal layer of the TMJ?

Answer 25

- Type A synovial cells - Type B synovial cells

Question 26

What is a type A synovial cell?

Answer 26

Macrophage-like cells that exhibit phagocytic functions and are capable of producing inflammatory cytokines

Question 27

What are type B synovial cells?

Answer 27

Fibroblast-like cells that synthesize hyaluronate which is a major component of the synovial fluid in both the superior and inferior compartments of the joint

Question 28

What causes inflammatory joint disease in the TMJ?

Answer 28

- Chronic or acute joint trauma may cause the Type A synovial cells to undergo a syncytial transformation into multinucleated giant cells that exhibit osteoclastic-like functions - the articular surfaces, including the joint meniscus, are subjected to cellular mediated surface resorption

Question 29

What can happen in inflammation of TMJ is sufficient intensity and duration?

Answer 29

bone are cartilagte resorb in the condylar head and condylar neck

Question 30

Answer 30

TMJ inflammation

Question 31

What is internal derangment of the TMJ?

Answer 31

the disc is trapped in the antero-medial position, causing limited opening, pain, and “clicking” upon opening

Question 32

What can be seen in arthritic degeneration of the TMJ?

Answer 32

- osteophytes are noted on the condylar heads - decreased vascularity is found in the retrodiscal area, leading to pain on function

Question 33

What can Ankylosis Resulting From Untreated Fracture lead to?

Answer 33

Loss of articular coverings and synovial membranes, leading to direct bone-to-bone fusion