The Otic Ganglion:

It is a peripheral parasympathetic ganglion which relays secretomotor fibres to the parotid gland. Topographically, it is intimately related to the mandibular nerve, but functionally it is a part of the glossopharyngeal nerve. The sympathetic root is derived from the plexus on the middle meningeal artery. It contains postganglionic fibres arising in the superior cervical ganglion. The fibres pass through the otic ganglion  without relay and reach the parotid gland via the auriculotemporal nerve. They are vasomotor in function. The sensory root comes from the auriculotemporal nerve and is sensory to the parotid gland.