Lec 5 Flashcards
You need this before you can attribute a headache to TMD.
Primary TMD diagnosis
In a normal disc position, in the sagittal plane, relative to the superior aspect of the condyle, the border between the low signal of the disc and the high signal of the retrodiscal tissue is located between which clock positions?
11:30 and 12:30
For a normal disc, in the sagittal plane, the intermediate zone is located between what?
The anterior-superior aspect of the condyle and the posterior-inferior aspect of the articular eminence.
Describe the position of the posterior band on the condyle when the mouth is closed.
Should be POSTERIOR to the 11:30 position.
Should NOT be anterior to the 11:30 position.
Location of the intermediate zone in disc displacement.
ANTERIOR to the superior part of the condyle.
What does the posterior band look like on an MRI?
Where the white and gray parts meet at the line.
Posterior band is WHITE on an MRI.
Diagnose the disc displacement:
In the closed mouth position, the disc is in an anterior position relative to the condylar head and the disc reduces upon opening of the mouth.
Medial and lateral displacement of the disc may also be present.
Clicking, popping, or snapping noises may occur with disc reduction.
A hx of prior locking in the closed mouth position coupled with interference in mastication precludes this dx.
Disc displacement with reduction.
Hx in disc displacement with reduction.
Hx of joint sounds
Dx:
1 click on opening, or 1 click on closing.
1 click in opening; 1 in closing, +1 click in lateral protrusive movements.
2 vertical clicks, or 1 vertical and 1 horizontal click
Disc displacement with reduction.
Dx:
In the MRI:
1) In the maximum intercuspal position, the posterior band of the disc is anterior to the 11:30 position and the intermediate zone of the disc is anterior to the condylar head; AND
2) On full opening, the intermediate zone of the disc is located between the condylar head and the articular eminence.
Disc displacement with reduction.
Only this can diagnose a lateral or medially displaced disc.
MRI
Dx:
In the closed mouth position, the disc is in an anterior position relative to the condylar head, and the disc intermittently reduces with opening of the mouth.
When the disc does not reduce with opening of the mouth, intermittent limited mandibular opening occurs.
When limited opening occurs, a maneuver may be needed to unlock the TMJ.
Medial and lateral displacement of the disc may also be present.
Clicking, popping, or snapping noises may occur with disc reduction.
Disc displacement with reduction with intermittent locking.
When does a jaw lock?
When the disc does NOT reduce when you open the mouth.
Hx for disc displacement with reduction with intermittent locking.
Jaw locks with limited opening, even for a moment, and then unlocks.
If there’s no sounds, then there’s no what?
Reduction
Limited opening means maximum assisted opening is less than how many mm?
40
Closed lock
When you can’t open your mouth all the way.
Open lock
When you can’t close your mouth all the way.
Dx:
History of:
1) Locked jaw so that the mouth cannot open all the way AND
2) Limitation in jaw opening severe enough to limit jaw opening and interfere with ability to eat.
Disc displacement WITHOUT reduction with limited opening.
T/F:
You know there’s NO reduction when the posterior band is anterior to the 11:30 position when the mouth is OPEN.
TRUE
Dx:
In the closed mouth position, the disc is in an anterior position relative to the condylar head and the disc does not reduce with opening of the mouth. Medial and lateral displacement of the disc may also be present. This disorder is NOT associated with current limited opening.
Exam:
Maximum assisted opening movement including vertical incisal overlap is greater than or equal to 40 mm.
Disc displacement without reduction without limited opening
Can you have TMJ noise (clicking during opening) in disc displacement without reduction?
Yes