ABSTRACT
MUSCLE n The platysma is a broad, thin muscle that spans the neck and is a key instrument for controlling
neck contour. • Origin: Pectoralis and deltoid muscle fascia • Insertion Anterior bers: Symphysis of the mandible and slightly laterally Posterior bers: Cross the mandible and insert into the superficial musculoaponeurotic
system (SMAS) • Blood supply Major: Branch of the submental artery Minor: Branch of the suprasternal artery
• Innervation: Cervical branch of the facial nerve • Action: Draws on the lower lip and angle of the mouth causing oblique wrinkling of the skin
of the neck2
n The supercial cervical fascia is a thin, aponeurotic lamina that immediately covers the platysma on its surface.