Which statement about disc displacement without reduction is true?

Which statement about disc displacement without reduction is true?

• A. It always presents with a loud click on opening
• B. It cannot cause limited opening
• C. It may present with restricted opening and without a joint click
• D. It is diagnosed only by CT

Answer: (C)

Disc displacement without reduction means the articular disc stays anterior to the condyle in both closed and opened positions, so it does not return to its normal place as the mouth opens. Because the disc doesn’t reduce, there isn’t the classic opening click you’d expect with disc displacement with reduction, and many patients have restricted mouth opening. This combination of limited opening and little or no joint sound is why the statement is true. Clinically, you might also see jaw deviation on opening or pain with movement. Imaging helps, but it isn’t diagnosed by CT alone; MRI is the preferred method to visualize the disc position and its relationship to the condyle, since CT mainly shows bony structures rather than soft tissue.

Disc displacement without reduction means the articular disc stays anterior to the condyle in both closed and opened positions, so it does not return to its normal place as the mouth opens. Because the disc doesn’t reduce, there isn’t the classic opening click you’d expect with disc displacement with reduction, and many patients have restricted mouth opening. This combination of limited opening and little or no joint sound is why the statement is true. Clinically, you might also see jaw deviation on opening or pain with movement. Imaging helps, but it isn’t diagnosed by CT alone; MRI is the preferred method to visualize the disc position and its relationship to the condyle, since CT mainly shows bony structures rather than soft tissue.