Facial muscle spasm, also known as facial muscle twitching or lateral facial muscle spasm. The twitches are paroxysmal and irregular, with varying degrees, and can be aggravated by fatigue, stress, and voluntary movements. The onset of the disease usually starts from the orbicularis oculi muscle and then involves the whole face. Facial muscle paralysis is characterized by shallowing of the nasolabial fold on the diseased side, drooping of the corners of the mouth, the mouth being drawn to the opposite side of the lesion, inability to pout and whistle, and air leakage from the corners of the mouth on the diseased side when puffing the cheeks. Due to the paralysis of the buccal muscle, it is easy to bite the buccal mucosa when chewing, and food is often trapped between the teeth and cheeks. In severe injury, facial muscle paralysis is significant, even seen when the face is at rest.