From edges of Deltoid and Pectoralis Major muscles upward to lower border of mandible.
Base of mandible; skin of cheek and lower lip; angle of mouth; orbicularis oris.
The Platysma muscle attaches to the mandible at the angle of the jaw and chin, and invaginates with the Depressor labii inferioris and Depressor anguli oris. American Academy of Manual Medicine
Draws mouth downward.
The Platysma muscle draws the corners of the mouth inferiorly and widens it (as in expressions of sadness and fright). Also draws the skin of the neck superiorly when teeth are clenched.
Innervation – Nerve control
Cervical branch of the facial nerve (CN VII).
The cervical branch of the facial nerve runs forward beneath the Platysma, and forms a series of arches across the side of the neck over the suprahyoid region.One branch descends to join the cervical cutaneous nerve from the cervical plexus. Also supplies the platysma muscle.
The facial nerve is the seventh cranial nerve, or simply cranial nerve VII. It emerges from the brainstem between the pons and the medulla, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity. It also supplies preganglionic parasympathetic fibers to several head and neck ganglia. Wiki
Branches of the Submental artery and Suprascapular artery.
The submental artery is the largest of the cervical branches of the facial artery, given off just as that vessel leaves the submandibular gland: it runs forward upon the mylohyoid, just below the body of the mandible, and beneath the digastric muscle.
The suprascapular artery (or transverse scapular artery) is a branch of the thyrocervical trunk. At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses the subclavian artery and the brachial plexus, running behind and parallel with the clavicle and subclavius muscle and beneath the inferior belly of the omohyoid to the superior border of the scapula. It passes over the superior transverse scapular ligament (unlike the suprascapular nerve, which passes below the ligament). Wiki
The masseter is a thick, somewhat quadrilateral muscle, consisting of two heads, superficial and deep. The fibers of the two heads are continuous at their insertion.
The temporal muscle, also known as the temporalis, is one of the muscles of mastication. It is a broad, fan-shaped muscle on each side of the head that fills the temporal fossa, superior to the zygomatic arch so it covers much of the temporal bone.
Pictures of muscles
Trigger Point Referrals