Oral medicine and oral cancer: T4a oral cavity carcinoma: 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 medicine and oral cancer: T4a oral cavity carcinoma

Sample item

Under the AJCC 8th edition, a carcinoma of the lower alveolus invades through the cortical bone of the mandible but does not reach the masticator space. Which T category applies?

AT4aBT4bCT2DT3

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

The answer and the reasoning

A. T4a

In the AJCC 8th edition, oral cavity tumours invading through the cortical bone of the mandible or maxilla, the maxillary sinus or the facial skin are T4a. T4b is invasion of the masticator space, pterygoid plates or skull base, or encasement of the carotid artery.

Option by option

A. T4a (correct)
Correct. Invasion through cortical bone is moderately advanced local disease, T4a.
B. T4b
T4b requires masticator space, pterygoid plate, skull base or carotid involvement.
C. T2
T2 is a smaller, shallower tumour without cortical invasion.
D. T3
T3 is defined by size and depth of invasion, not by invasion through bone.

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.

Questions about this Dentistry question

What is the answer to this Dentistry question?

The best answer is A, T4a. In the AJCC 8th edition, oral cavity tumours invading through the cortical bone of the mandible or maxilla, the maxillary sinus or the facial skin are T4a.

Why is "T4b" not the answer?

T4b requires masticator space, pterygoid plate, skull base or carotid involvement.

Why is "T2" not the answer?

T2 is a smaller, shallower tumour without cortical invasion.

Why is "T3" not the answer?

T3 is defined by size and depth of invasion, not by invasion through bone.

What concept does this question test?

It tests Oral medicine and oral cancer: T4a oral cavity carcinoma in Dentistry. T4b is invasion of the masticator space, pterygoid plates or skull base, or encasement of the carotid artery.

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 medicine and oral cancer: T4a oral cavity carcinoma?

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.