Depressor anguli oris muscle

The depressor anguli oris ( " corner of the mouth depressors ," Syn musculus triangularis ) is a skin muscle of the head. The muscle originates at Margo inferior of the mandible (lower jaw) and radiates into the mouth. At its origin it is adherent to the platysma in the neck area to its muscle fibers are interwoven with those of the musculus orbicularis oris and risorius. The muscle is part of the facial muscles and pulls the corners of the mouth downward. It is innervated by the ramus marginalis mandibulae of the facial nerve.