TMD, facial muscles Flashcards
TMJ vs. TMD
TMJ: stomatognathic system
TMD: group of MSK disorders w/ signs and symptoms
True or false: TMD just involves TMJ joint?
False! muscles of mastication, c-spine etc are involved
Peak age of prevalence of TMD?
35-45
What two bones is the TMJ made of?
Process of the temporal bone and head of the condyle
What kind of joint is TMJ
Compound, complex (moves in three planes) synovial jt.
What muscle attaches on the coronoid process?
Temporalis
What is the articulating part of TMJ?
Articular tubercle and head of the condyle
What shape are the articulating surfaces of the TMJ?
Articular tubercle: convex
Head of condyle: convex
Convex on convex
What shape is the articular disc and what bearing does this have on its function?
Biconcave, thicker at the ends, thinner at the middle for stability due to surfaces being convex on convex
What parts of the articular disc are innervated?
Anterior and posterior
Describe the central portion of the articular disc. Why?
Aneural and avascular. This is where all the force goes, it would be really painful if this weren’t the case.
The TMJ is made of what?
fibrocartilage
What is fibrocartilage (what TMJ is made of) good at:
resisting shear and compressive forces
DDD in TMJ prognosis?
not bad! fibrocartilage repairs
Superior and inferior stratum are what and part of ________
Ligamentous structures. Bilaminar zone of the TMJ.
The articular disc breaks joint into what?What are the actions of these two parts?
superior and inferior joint space
Superior: restricts forward movement of disc during opening
Inferior: assists pulling disc posteriorly during closing
Describe the anterior attachment of the intra articular disc
Weakest part of the joint
The lateral pterygoid attaches here
Explain the retrodiscal tissue/pad
highly vascular and neural
Describe the capsular ligament
Lateral and medial attachment of the intra-articular disc to the TMJ
Covers the entire joint, retains synovial fluid, resists separation
What covers the entire TMJ, retains synovial fluid and resists separation?
Capsular ligament
Describe the discal ligaments
LDL, MDL named for being on the medial/lateral poles of the condyle
Which is thinner LDL or MDL?
LDL
Role of the temporomandibular ligament
tightens to give lateral stability when the mouth opens: controls rotation of the condyle, limits posterior movement of the condyle
Calcification of what ligament is called Eagles syndrome?
Stylomandibular