The nerve that supplies skin over the angle of mandible, if involved in parotid injuries forms a part of anatomical basis for gustatory sweating:
**Core Concept**
The greater auricular nerve is a key branch of the cervical plexus that provides sensory innervation to the skin over the angle of the mandible. This nerve also has a significant role in the development of gustatory sweating (Freud's syndrome) when it is damaged in conjunction with the auriculotemporal nerve, which carries parasympathetic fibers from the otic ganglion.
**Why the Correct Answer is Right**
The greater auricular nerve is responsible for conveying sensory information from the skin over the angle of the mandible. In the context of parotid injuries, damage to this nerve can lead to aberrant regeneration of the auriculotemporal nerve, which carries parasympathetic fibers from the otic ganglion. This aberrant regeneration can result in the formation of a synkinesis between the parotid gland and the skin over the angle of the mandible, leading to gustatory sweating.
**Why Each Wrong Option is Incorrect**
**Option A:** The auriculotemporal nerve carries parasympathetic fibers from the otic ganglion but does not supply the skin over the angle of the mandible. It is involved in the development of gustatory sweating but is not the primary nerve responsible for sensory innervation to this area.
**Option C:** The zygomaticotemporal nerve provides sensory innervation to the skin over the zygomatic region and is not involved in the development of gustatory sweating in the context of parotid injuries.
**Option D:** The buccal nerve provides sensory innervation to the buccal mucosa and is not involved in the development of gustatory sweating in the context of parotid injuries.
**Clinical Pearl / High-Yield Fact**
In cases of parotid injuries, damage to the greater auricular nerve can lead to the development of gustatory sweating, a condition characterized by excessive sweating of the skin over the angle of the mandible in response to stimuli that normally induce salivation. This condition is a classic example of aberrant regeneration and synkinesis.
**✓ Correct Answer: B. Greater auricular nerve**