Week 12 - Temporomandibular Joint Flashcards
Describe mandible growth
different parts grow in congruence with each other (independently but at the same time) but in general tends to happen in anterior-posterior direction as well as in a flaring direction
What happens in underdeveloped ramus/body?
steeper incline/angle of jaw, can lead to crowding issues
What happens in an overdeveloped ramus/body?
Flat angle of jaw
What are ruffini corpuscles used for?
Proprioception (where mandible is in space)
What are pacinian corpuscles used for?
dynamic mechanoreception (chewing)
What are golgi tendon organs used for?
static mechanoreception (rest)
What are free nerve endings used for?
detect pain
What is the TMJ classified as?
synovial sliding-ginglymoid joint
What does synovial permit?
permits movement between two bones
What does sliding describe?
the second part of jaw opening, sliding anterior of the condyle over the glenoid fossa
What does ginglymoid describe?
the first part of opening, hinge portion
What is the joint cavity filled with and what is it derived from?
filled with synovial fluid (1 mL) that is derived from villus cells which line the internal space of the capsule
What does the fibrous disc separate?
The bone preventing damage
How do the condylar neck and head develop?
By endochondral ossification
What is the multidirectional growth capacity?
unlike long bones of the body, which also develop by endochondral ossification, the cartilage cells in the condylar head and neck do not exhibit ordered columns (characteristic of the epiphyseal growth plates in long bones)
What encapsulates the entire joint?
Fibrous capsule
What attaches to joint capsule and articular disc (meniscus)?
Superior lateral pterygoid
What attaches to condylar neck in pterygoid fossa?
Inferior lateral pterygoid
What is the glenoid fossa?
bony part of the temporal bone that allows for articular surface of mandibular condyle to fit in
What does the glenoid fossa have?
collagen fiber going in multiple directions allowsing for a more robust surface of articulation (more friction and more prone to damage)
What is the posterior slope of the TMJ’s articular emininance inner perpendicular collagen fibers responsible for?
resisting compression of the mandibular condyle against the articular surface of bone
What are articulating surfaces covered with?
A layer of fibrous tissue