TMJ Flashcards
What innervates pain in the TMJ?
free nerve endings
What innervates static mechanoreception in the TMJ?
golgi tendon organs
What innervates dynamic mechnoreception in the TMJ?
pacinian corpuscles
What innervates proprioception in the TMJ?
ruffini corpuscles
The TMJ is classified as what type of joint?
a synovial sliding-ginglymoid
(hinged)
Synovial joints permit movement between ____ bones
two
Each bone in the TMJ is covered by what kind of cartilage?
hyaline
Where is the synovial fluid derived from?
villus cells
Both the condylar neck and head develop by _________ ossification.
endochondral
How is the growth of the TMJ different from long bones in the body?
- multidirectional growth capacity
- cartilage cells in the condylar head and neck do not exhibit ordered columns
Bones of the TMJ are the…
glenoid fossa and the mandibular condyle
What does the superior head of the lateral pterygoid muscle attach to?
joint capsule and articular disc
What does the inferior head of the lateral pterygoid muscle attach to?
condylar neck in the pterygoid fovea
The articulating surfaces are covered with a layer of…
fibrous tissue
With increasing age, the deeper portions of the fibrous covering of the TMJ may exhibit islands of _______
cartilage
condylar head of child
Condylar head of adult
articular disc of young adult
articular disc of elderly adult
What is the retrodiscal connective tissue (bilaminar zone) made of?
collagen and elastic fibrous connective tissue, fat cells, and is highly vascular
What do the elastic fibers of the bilaminar zone of the TMJ insert into?
petrotympanic fissure
Retrodiscal Connective Tissue (a.k.a. bilaminar zone)
The TMJ synovial membrane consists of what layers?
- fibrous capsule
- vascular subintima
- intimal layer
What does anterior dislocation of the disc do to the position of TMJ?
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.
What two cell type are in the intimal layer of the TMJ?
- Type A synovial cells
- Type B synovial cells
What is a type A synovial cell?
Macrophage-like cells that exhibit phagocytic functions and are capable of producing inflammatory cytokines
What are type B synovial cells?
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
What causes inflammatory joint disease in the TMJ?
- 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
What can happen in inflammation of TMJ is sufficient intensity and duration?
bone are cartilagte resorb in the condylar head and condylar neck
TMJ inflammation
What is internal derangment of the TMJ?
the disc is trapped in the antero-medial position, causing limited opening, pain, and “clicking” upon opening
What can be seen in arthritic degeneration of the TMJ?
- osteophytes are noted on
the condylar heads - decreased vascularity is found in the retrodiscal area, leading to pain on function
What can Ankylosis Resulting From Untreated Fracture lead to?
Loss of articular coverings and
synovial membranes, leading to
direct bone-to-bone fusion
