Functional Disorders of the TMJ Flashcards
in the condyle-disc complex, the disc is ___ and ___ bound to the condyle by the ___ ligaments
- laterally and medially
- discal collateral
the only physiologic movement that can occur between the condyle and the articular disc is ___
rotation
rotational movement of the condyle-disc complex is limited by what?
the length of the discal collateral ligaments, inferior retrodiscal lamina posteriorly, anterior capsular ligament anteriorly, morphology of the disc, degree of interarticular pressure, superior lateral pterygoid muscle, and superior retrodiscal lamina
the only physiologic translatory movement occurs between the ___ and the ___
condyle-disc complex and the articular fossa
describe the steps of normal opening movement
- mouth opens and condyle moves forward
- disc rotates posteriorly on the condyle
- superior retrodiscal lamina lengthens
- condyle-disc complex translates out of the fossa
during normal opening movement, once the condyle-disc complex translates out of the fossa, ___ maintains the condyle on the thinner intermediate zone of the articular disc and prevents the thicker anterior border from passing posteriorly through the discal space between the ___ and ___
- interarticular pressure provided by the elevator muscles
- condyle and the articular surface of the eminence
the ___ is the only structure that can retract the disc posteriorly
superior retrodiscal lamina
what happens if the morphology of the disc is altered and the discal ligaments become elongated (internal derangement)? is this movement normal in a healthy joint? what is its degree determined by?
the disc is permitted to slide (translate) across the articular surfaces of the condyle. this type of movement is not present in the healthy joint. it’s degree is determined by changes that have occurred in the morphology of the disc and the degree of elongation of the discal ligaments.
what happens when the mouth closes during internal derangement?
when the mouth closes, the interarticular pressure is lower, so the disc can once again be displaced forward by tonicity of the superior lateral pterygoid muscle
in the healthy joint, the surfaces of the condyle, disc, and articular fossa are ___, allowing ___ movement
slippery, allowing easy, frictionless movement
describe reciprocal clicking
- during mandibular opening, a sound is heard when the condyle moves across the posterior border of the disc to its normal position on the intermediate zone.
- during closing, the normal disc position is maintained until the condyle returns to very near the closed joint position.
- as the closed joint position is approached, the posterior pull of the superior retrodiscal lamina is decreased.
- the combination of disc morphology and pull of the superior lateral pterygoid muscle allows the disc to slip back into the more anterior displaced position. this final movement of the condyle across the posterior border of the disc creates a second clicking sound (“reciprocal click”)
___ describes actual dislocation of the articular surfaces
functional dislocation with reduction
T or F:
during functional dislocation with reduction, the patient is unable to maneuver the joint successfully to reduce the disc back to its functional position
false
is functional dislocation with reduction painful?
may or may not be painful depending on the severity and duration of the lock and the integrity of the structures in the joint
what happens during functional dislocation with reduction of episodes of catching/locking become more frequent and chronic?
ligaments break down and innervation is lost. Pain becomes less associated with ligaments and more related to forces placed on the retrodiscal tissues.