Damage to the great auricular nerve, with consequent clinical deficits, is a common surgical complication in facial aesthetic and in head and neck procedures such as parotidectomy, neck dissection, rhytidectomy and platysma flap operations. Hence, a thorough knowledge of nerve anatomy, particularly its potential variations, is critical in reducing the associated operative morbidity. Accordingly, we report an unusual variation of the anterior branch of the great auricular nerve noted in an 81-year-old female cadaver. The nerve was observed to course into the submandibular region anterior and superficial to the internal jugular vein, communicating with the cervical branch of the facial nerve, while independently innervating the platysma muscle. Although several anatomical variations of the branches of the cervical plexus have been documented, our report describes unique innervation of the platysma muscle by the great auricular nerve, which provides a new insight on the motor component of the nerve.

Facial muscles are known to have a variable anatomy. Such anatomical variations can affect facial expressions. A natural smile is produced by contracting several muscles of facial expression, including the muscles invested in the superficial musculoaponeurotic system. Change in the width of the mouth on smiling is a known iatrogenic complication affecting the risorius muscle when using Botulinum Neurotoxin as a non-invasive treatment for masseteric hypertrophy. Also damage to the risorius muscle, with consequent clinical deficits, is a common surgical complication in facial aesthetic, oncologic and other head and neck procedures such as parotidectomy and rhytidectomy. Hence, a thorough knowledge of muscle anatomy, particularly its potential variations, is critical in reducing the associated operative morbidity. Accordingly, we report an unusual variation of the transversus nuchal muscle fused with the risorius muscle noted in an 83-year-old female body cadaver.