TMJ - Slides Flashcards
What type of joint is the TMJ?
synovial condylar ovoid
What is the benefit of the TMJ being lined with fibrocartilage?
more durable - strong/rigid which makes it optimal for tendunous insertion
The temporal bone articulates with the mandible via its… which articulates with the ____ of the mandible
GLENOID/MANDIBULAR FOSSA
MANDIBULAR CONDYLE
Which two muscles insert on the coronoid process?
temporalis and masseter
Which muscles depress the TMJ?
Suprahyoids & lateral pterygoid
The articular disc of the TMJ is aneural in the ____, whereas the ___ is vascular and neural
centre, periphery
The first 20mm of jaw opening only involves…
rotational movement of the condyle within the socket
For the mouth to open more than 20mm, the disc has to move forward and down the ____ - this movement is called ____
articular eminence
translation
Why is anterior disc displacement of the TMJ painful?
when the disc is pulled too far forward, the retrodiscal tissue (which is pain sensitive) gets compressed by the condyle while the disc gets stuck anteriorly
What likely occurs when the jaw locks?
The articular disc is stuck anteriorly; the retrodiscal tissue is compressed in the glenoid fossa by the mandibular condyle. When the person tries to open their jaw again, the anteriorly displaced disc prevents the condyle from being able to move forward
What is a “pseudo disc”?
when the retrodiscal tissue becomes scar tissue and can functionally replace the disc!
What does a C-curve suggest? Which direction does a REVERSE C-curve deviate?
C curve = capsular restriction, hypomobility on the side of deviation
Reverse c-curve = to the right
What does an S curve suggest? An S-curve will go which direction first?
suggests muscle imbalance
S curve will go to the left, THEN to the right
With an S curve, the chin will deviate to the affected/unaffected side first?
affected
Which lateral pterygoid head attaches to the articular disc and capsule?
superior
The lateral pterygoid heads originate on what bones and insert on what bones?
originate from sphenoid
insert on mandible and articular disc
The temporomandibular ligament checks which excess movements?
forward, backward, and lateral
The sphenomandibular ligament checks which movements?
it’s a suspensory ligament during wide mandibular openings
When the mouth is open wide, what will the state of the temporomandibular and sphenomandibular ligaments be?
temporomandibular ligament slackens, sphenomandibular ligament becomes taught (as a suspensory ligament)
The stylomandibular ligament separates the __ and __ muscles
masseter, medial pterygoid