Zygomaticus Major Muscle
The zygomatic major is a muscle of the human body. It is a muscle of facial expression which draws the angle of the mouth superiorly and posteriorly (smile). Like all muscles of facial expression, the zygomatic major is innervated by the facial nerve (the seventh cranial nerve), more specifically, the buccal and zygomatic branches of the facial nerve. The zygomaticus extends from each zygomatic arch (cheekbone) to the corners of the mouth. It raises the corners of the mouth when a person smiles. Dimples may be caused by variations in the structure of this muscle.