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.