Oral and maxillofacial surgery and facial fractures: closed lock of the TMJ: practice question

A Dentistry question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Dentistry · Oral and maxillofacial surgery and facial fractures: closed lock of the TMJ

Sample item

A woman who previously had a clicking jaw now cannot open beyond 25 mm and the jaw deviates to the painful side on opening. The click has disappeared. What is the likely diagnosis?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Anterior disc displacement without reduction

In disc displacement without reduction the disc stays in front of the condyle and blocks translation, producing a closed lock with limited opening, deviation to the affected side and loss of the earlier click. Bony ankylosis is hard-end-feel and usually follows trauma or infection.

Option by option

  • A. Anterior disc displacement without reduction (correct)

    Correct. A disc that no longer reduces causes a closed lock after earlier clicking.

  • B. Anterior disc displacement with reduction

    With reduction, opening is normal and a click occurs as the disc recaptures.

  • C. Bony ankylosis of the joint

    Bony ankylosis gives progressive near-total immobility without prior clicking.

  • D. Condylar hyperplasia

    Condylar hyperplasia causes asymmetry and malocclusion, not locking.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Dentistry question

What is the answer to this Dentistry question?

The best answer is A, Anterior disc displacement without reduction. In disc displacement without reduction the disc stays in front of the condyle and blocks translation, producing a closed lock with limited opening, deviation to the affected side and loss of the earlier click.

Why is "Anterior disc displacement with reduction" not the answer?

With reduction, opening is normal and a click occurs as the disc recaptures.

Why is "Bony ankylosis of the joint" not the answer?

Bony ankylosis gives progressive near-total immobility without prior clicking.

Why is "Condylar hyperplasia" not the answer?

Condylar hyperplasia causes asymmetry and malocclusion, not locking.

What concept does this question test?

It tests Oral and maxillofacial surgery and facial fractures: closed lock of the TMJ in Dentistry. Bony ankylosis is hard-end-feel and usually follows trauma or infection.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Oral and maxillofacial surgery and facial fractures: closed lock of the TMJ?

Learn the dental formula, eruption ages and tooth structure once, as tables. Then use the flashcards and the other Dentistry questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.