Oral and maxillofacial surgery and facial fractures: complication of sagittal split osteotomy: 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: complication of sagittal split osteotomy

Sample item

After bilateral sagittal split ramus osteotomy to correct mandibular prognathism, which complication is the most common?

AComplete facial nerve palsyBAltered sensation in the lower lip and chinCPermanent trismus from ankylosisDAvascular necrosis of the maxilla

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

The answer and the reasoning

B. Altered sensation in the lower lip and chin

The inferior alveolar nerve runs close to the osteotomy and may be stretched or compressed, causing temporary or sometimes permanent numbness of the lower lip and chin. Most patients recover sensation over months.

Option by option

A. Complete facial nerve palsy
The facial nerve is rarely injured in this operation.
B. Altered sensation in the lower lip and chin (correct)
Correct. Inferior alveolar nerve disturbance is the commonest complication.
C. Permanent trismus from ankylosis
Ankylosis is rare after this operation.
D. Avascular necrosis of the maxilla
Maxillary avascular necrosis is a risk of Le Fort I osteotomy and not of a mandibular procedure.

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 B, Altered sensation in the lower lip and chin. The inferior alveolar nerve runs close to the osteotomy and may be stretched or compressed, causing temporary or sometimes permanent numbness of the lower lip and chin.

Why is "Complete facial nerve palsy" not the answer?

The facial nerve is rarely injured in this operation.

Why is "Permanent trismus from ankylosis" not the answer?

Ankylosis is rare after this operation.

Why is "Avascular necrosis of the maxilla" not the answer?

Maxillary avascular necrosis is a risk of Le Fort I osteotomy and not of a mandibular procedure.

What concept does this question test?

It tests Oral and maxillofacial surgery and facial fractures: complication of sagittal split osteotomy in Dentistry. Most patients recover sensation over months.

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 Oral and maxillofacial surgery and facial fractures: complication of sagittal split osteotomy?

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.