Platysma Muscles

Description

Arising from the superficial fascia over the pectoralis major and deltoid, the paired platysma muscles fan superiorly across the anterolateral neck toward the inferior border of the mandible and lower face. Their thin sheets lie superficial to the sternocleidomastoid and the anterior cervical strap muscles, crossing obliquely over the clavicle and the lateral cervical region. Deep to them, the bony framework of the skull (mandible, maxilla, orbital margins) and the cervical vertebrae provide fixed landmarks, while the upper ribs and sternum define the inferior boundary of the field. Understanding the platysma in relation to the sternocleidomastoid matters in facial expression anatomy and in neck surgery, because this layer defines the plane of elevation in subplatysmal dissection. Weakness or asymmetric contraction is a common contributor to platysmal banding with aging, and spasm can accentuate lower facial grimacing. Surgeons also use the platysma as a landmark when planning rhytidectomy, submental approaches, and drainage of superficial neck infections, where staying superficial protects the deeper neurovascular structures. This artwork fits gross anatomy teaching of the cervical fascia and muscles of facial expression, and it pairs well with chapters on the superficial neck in head and neck surgery texts. It also supports clinical education on aesthetic neck rejuvenation, including botulinum toxin injection planning and the anatomy behind platysmaplasty. Anatomical accuracy verified by SciePro's Medical Advisory Board.