The stapedius muscle nerve. The stapedius muscle nerve is one of the branches of facial nerve, and facial nerve is one of the main innervation of parotid gland. Facial nerve is mainly responsible for the sensory and motor functions of the face and mouth, including masticatory muscles, tensor tympani, stapedius muscles and so on. Because the parotid gland is located in the face, its innervation is also related to the facial nerve. Therefore, the innervation of parotid gland includes stapedial nerve.