Orthodontics and paediatric dentistry: functional matrix theory: 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.

Try it

Dentistry · Orthodontics and paediatric dentistry: functional matrix theory

Sample item

According to Moss's functional matrix theory, what drives growth of the skeletal units of the face?

AGrowth of the surrounding soft tissue functional matricesBHormonal control from the pituitary aloneCSutural pressure from the brainDGenetic control inside the bone and cartilage themselves

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

The answer and the reasoning

A. Growth of the surrounding soft tissue functional matrices

The functional matrix theory holds that the skeleton grows in response to the growth and functional demands of the soft tissue matrices, such as muscles, glands and airway. Skeletal units are secondary and passive. The theory contrasts with the genetic and cartilage-driven models.

Option by option

A. Growth of the surrounding soft tissue functional matrices (correct)
Correct. Soft tissue functional matrices drive skeletal growth.
B. Hormonal control from the pituitary alone
Pituitary control is not the basis of this theory.
C. Sutural pressure from the brain
Sutural pressure from the brain is not the mechanism proposed here.
D. Genetic control inside the bone and cartilage themselves
Intrinsic genetic control of bone is the competing view.

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, Growth of the surrounding soft tissue functional matrices. The functional matrix theory holds that the skeleton grows in response to the growth and functional demands of the soft tissue matrices, such as muscles, glands and airway.

Why is "Hormonal control from the pituitary alone" not the answer?

Pituitary control is not the basis of this theory.

Why is "Sutural pressure from the brain" not the answer?

Sutural pressure from the brain is not the mechanism proposed here.

Why is "Genetic control inside the bone and cartilage themselves" not the answer?

Intrinsic genetic control of bone is the competing view.

What concept does this question test?

It tests Orthodontics and paediatric dentistry: functional matrix theory in Dentistry. Skeletal units are secondary and passive. The theory contrasts with the genetic and cartilage-driven models.

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 Orthodontics and paediatric dentistry: functional matrix theory?

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.