Full Title: Zygomaticus Muscle
Author: Marcia Tillotson
Date of Publication: December 12, 2012
Research Paper Text:
The Zygomaticus Muscle is one of several canine facial muscles that assist in moving the lips. In addition, it is a major muscle that also affects animal facial expression. According to Donald R. Adams in his book, `Canine Anatomy: A Systemic Study` Fourth Edition, “The zygomaticus muscle extends cranioventrally from the scutiform cartilage of the ear to the caudal edge of the superior lip, where its fibers radiate into the obicularis oris muscle.” P. 125 The zygomaticus muscle is a small muscle that pulls the corners of the mouth upward and rearward. Drs. Howard E. Evans PhD and Alexander de Lahunta DVM PhD explain in their book `Guide to the dissection of the dog` 7th edition, that the zygomaticus, as well as, all of the deep muscles of the nose and lip “are innervated by the facial nerve and most all by the dorsal or ventral buccal branches of the facial nerve”. P. 191. Its actions are to raise and laterally move the commissure of the lips. It is considered by many as the basic “smile” muscle.