Identification: dental eruption: practice question

A Forensic Medicine 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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Forensic Medicine · Identification: dental eruption

Sample item

A youth accused of an offence claims to be 15 years old. A dental radiograph shows fully erupted third molars on all four sides. What can reasonably be concluded?

AThird molars erupt at about 6 years, so nothing can be saidBHe is probably older than about 17 years, since third molars erupt from about 17 to 25 yearsCHe is certainly over 30 yearsDHe is certainly below 15 years

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

The answer and the reasoning

B. He is probably older than about 17 years, since third molars erupt from about 17 to 25 years

The third molar erupts between about 17 and 25 years, and it is the last tooth to erupt. Full eruption therefore makes a claim of age 15 unlikely. Dental evidence gives a range, and variation between persons and populations remains.

Option by option

A. Third molars erupt at about 6 years, so nothing can be said
The first molars erupt at about 6 years, not the third molars.
B. He is probably older than about 17 years, since third molars erupt from about 17 to 25 years (correct)
Correct. Third molar eruption begins around 17 years, so the claim of 15 is doubtful.
C. He is certainly over 30 years
Eruption of third molars gives no basis to claim an age over 30 years.
D. He is certainly below 15 years
Third molar eruption does not occur at below 15 years in typical cases.

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 Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is B, He is probably older than about 17 years, since third molars erupt from about 17 to 25 years. The third molar erupts between about 17 and 25 years, and it is the last tooth to erupt.

Why is "Third molars erupt at about 6 years, so nothing can be said" not the answer?

The first molars erupt at about 6 years, not the third molars.

Why is "He is certainly over 30 years" not the answer?

Eruption of third molars gives no basis to claim an age over 30 years.

Why is "He is certainly below 15 years" not the answer?

Third molar eruption does not occur at below 15 years in typical cases.

What concept does this question test?

It tests Identification: dental eruption in Forensic Medicine. Full eruption therefore makes a claim of age 15 unlikely. Dental evidence gives a range, and variation between persons and populations remains.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Identification: dental eruption?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine 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.