Platysma Muscle

Description

Running as a thin, superficial sheet within the superficial cervical fascia, the platysma spreads from the inferior border of the mandible and lower face to the skin and subcutaneous tissue over the anterior neck and upper thorax. From an anterolateral three-quarter perspective, its fibers are seen coursing inferomedially across the anterolateral neck, draping over the sternocleidomastoid and approaching the midline near the level of the hyoid and thyroid cartilage. Superiorly, the muscle blends with the depressor anguli oris and adjacent perioral musculature at the angle of the mouth, while inferiorly it fans toward the clavicle and upper pectoral region. The tissue is wispy. That matters. For teaching surface anatomy, this view clarifies why platysma borders can be hard to define in dissection and why its contraction produces vertical platysmal bands and neck wrinkling with aging. Surgeons also care about the layer: during subplatysmal flap elevation in neck dissection or rhytidectomy, staying in the correct plane protects the marginal mandibular and cervical branches of the facial nerve and helps control bleeding from superficial veins such as the external jugular system. Weakness after parotid or submandibular surgery often presents as lower lip asymmetry and neck skin laxity, and you can trace the relevant fiber direction here. Use this plate in gross anatomy and head and neck modules to orient learners to the superficial cervical fascia and the relationship between platysma, sternocleidomastoid, and lower facial expression muscles. It also fits well in ENT and plastic surgery teaching materials covering subplatysmal dissection, management of platysmal bands (including chemodenervation), and safe incision planning along relaxed skin tension lines of the neck. Anatomical accuracy verified by SciePro's Medical Advisory Board.