**Question:** An 8-year-old boy was suffering from a severe infection of the right middle ear. Within the course of a week, the infection had spread to the mastoid antrum and the mastoid air cells. The organisms did not respond to antibiotics, so the surgeon decided to perform a radical mastoid operation. Following the operation, it was noticed that the boy's face was distorted. The mouth was drawn upward to the left, and he was unable to close his right eye. Saliva tended to accumulate in his right cheek and dribble from the corner of his mouth. What structure was most likely damaged during the operation?

**Core Concept:** The question is asking about a surgical complication that occurred post-radical mastoid operation due to a spread of the infection. The mastoid operation is a surgical procedure performed to treat infections in the mastoid air cells and mastoid antrum. These areas are part of the temporal bone, which is the bone that forms the side of the skull behind the ear.

**Why the Correct Answer is Right:** The correct answer, **C. Facial Nerve**, is related to the facial nerve (CN VII) that is responsible for controlling facial muscles and movements. In this case, the facial nerve was likely damaged during the radical mastoid operation. The damage to the facial nerve can lead to the observed symptoms, including the distorted facial appearance, inability to close the right eye, and accumulation of saliva in the right cheek and dribbling out of the corner of the mouth.

**Why Each Wrong Option is Incorrect:**

A. **Temporal Bone:** Although the question mentions that the mastoid operation was performed, it is not the correct answer because the temporal bone itself is not responsible for the observed symptoms. The temporal bone is the structure that was operated on, not the one causing the symptoms.

B. **Parotid Gland:** The parotid gland is responsible for producing saliva, but it doesn't cause the observed symptoms. The facial nerve damage is the cause of the salivary accumulation and dribbling.

D. **Oculomotor Nerve (CN III):** The oculomotor nerve controls eye movements, not the facial appearance or salivary secretion issues. Facial nerve damage causes the symptoms mentioned in the question.

**Clinical Pearls:** In this scenario, the facial nerve is damaged during the surgery, leading to the observed symptoms. The facial nerve is responsible for controlling facial muscles and movements, including the closure of the right eye and saliva production in the right cheek. The patient's facial appearance is distorted due to the facial nerve damage, and the salivary accumulation and dribbling are caused by the inability to close the right eye and control facial muscles, respectively.