Oral Surgery · single question
A patient develops hoarseness of voice AFTER thyroid surgery. Which nerve is MOST likely injured?
Show answer and explanation
Correct answer: D. Recurrent laryngeal nerve (RLN) — innervates all intrinsic laryngeal muscles except cricothyroid
- A. The superior laryngeal nerve also branches near the thyroid — its external branch innervates the cricothyroid. Injury causes voice pitch problems, not primarily hoarseness.
- B. The hypoglossal nerve innervates tongue muscles — not related to thyroid surgery complications.
- C. The glossopharyngeal nerve is not near the thyroid gland and not at risk in thyroid surgery.
- D. Correct. The RECURRENT LARYNGEAL NERVE (branch of CN X vagus) is at significant risk during thyroid surgery because it runs in the tracheoesophageal groove and passes close to the thyroid gland on each side. The RLN innervates ALL intrinsic laryngeal muscles EXCEPT the cricothyroid. Unilateral RLN damage → hoarseness (weak/paralyzed vocal cord). Bilateral RLN damage → aphonia and potentially fatal airway obstruction.