Nerve damaged in radical mastoidectomy is –
**Core Concept**
Radical mastoidectomy is a surgical procedure performed to remove extensive disease in the mastoid portion of the temporal bone, often due to chronic otitis media. The surgery involves removal of the mastoid air cells and sometimes the middle ear ossicles. The surgical approach requires careful preservation of surrounding structures, including cranial nerves.
**Why the Correct Answer is Right**
The nerve most commonly damaged during radical mastoidectomy is the facial nerve (cranial nerve VII). The facial nerve runs through the temporal bone and is at risk of injury during mastoid surgery. Damage to the facial nerve can result in facial weakness or paralysis, including weakness of the muscles of facial expression, taste disturbances, and other complications.
**Why Each Wrong Option is Incorrect**
* **Option A:** The trigeminal nerve (cranial nerve V) is not typically at risk during radical mastoidectomy. It is responsible for sensation in the face and motor control of muscles of mastication.
* **Option B:** The vagus nerve (cranial nerve X) is not commonly damaged during radical mastoidectomy. It is involved in various functions, including swallowing, voice production, and parasympathetic innervation of various organs.
* **Option C:** The glossopharyngeal nerve (cranial nerve IX) is not typically at risk during radical mastoidectomy. It is involved in swallowing, taste, and parasympathetic innervation of the parotid gland.
**Clinical Pearl / High-Yield Fact**
The facial nerve is often referred to as the " nerve of the face" due to its wide distribution and involvement in various facial functions. During mastoid surgery, careful identification and preservation of the facial nerve are crucial to avoid postoperative complications.
**Correct Answer:** D. Facial nerve.