s10 - TMJ Disorders Flashcards
(110 cards)
What type of joint is the temporomandibular joint (TMJ)?
A diarthrodial synovial joint.
What are the two main compartments of the TMJ?
The superior and inferior compartments.
What type of motion occurs in the inferior compartment of the TMJ?
Hinge (ginglymoid) motion.
What type of motion occurs in the superior compartment of the TMJ?
Translatory (arthrodial) movement.
What is the function of synovial fluid in the TMJ?
Lubrication and nutrition of avascular joint structures.
What are the main bony components of the TMJ?
The mandibular condyle and temporal bone (glenoid fossa and articular eminence).
What type of cartilage covers the TMJ surfaces?
Dense fibrous connective tissue (not hyaline cartilage).
What are the three regions of the articular disc?
Anterior band, intermediate zone, and posterior band.
What structure stabilizes the articular disc to the condyle during function?
The superior head of the lateral pterygoid muscle.
What is the role of the retrodiskal tissue in TMJ function?
It provides vascular supply and elasticity, limiting excessive anterior translation of the disc.
What are the two primary types of TMJ movement?
Rotation and translation.
Which part of the TMJ is responsible for rotational movement?
The inferior joint compartment (between condyle and disc).
Which part of the TMJ is responsible for translatory movement?
The superior joint compartment (between disc and temporal bone).
How much pure hinge movement is possible in normal mandibular function?
About 2.5 cm at the incisal edges.
What is the maximum forward translation movement of the condyle?
Approximately 1.5 cm.
What structure prevents excessive posterior movement of the condyle?
The inner horizontal portion of the temporomandibular ligament.
What happens to the condyle-disc complex during mandibular opening?
It rotates first, then translates forward along the articular eminence.
How does lateral excursion of the mandible occur?
One condyle rotates while the other translates forward (Bennett movement).
What are the main arteries supplying the TMJ?
Superficial temporal and maxillary arteries.
Which artery supplies the anterior region of the TMJ?
The masseteric artery.
What is the function of the venous plexus in the retrodiskal tissue?
It fills and empties during jaw movements to maintain joint stability.
What nerve primarily innervates the TMJ?
The auriculotemporal nerve.
Which additional nerves contribute to TMJ innervation?
Masseteric nerve and posterior deep temporal nerve.
What type of nerve fibers are most common in the TMJ?
Vasomotor and vasosensory fibers involved in pain and synovial fluid production.