Platysma

Original Editor - Manisha Shrestha

Top Contributors - Jacintha McGahan, Manisha Shrestha and Kim Jackson

Description

Platysma is a broad, thin sheet like muscle that lies superficially at the anterolateral aspect of neck bilaterally.

Origin

Platysma

It originates in the upper thoracic and shoulder regions from a fascia that covers the pectoralis major and deltoid muscles.

Insertion

The fibers travel superomedially over the anterolateral aspect of the neck, to insert on the mandible, the skin and subcutaneous tissue of the lower face.

Nerve

Cervical branch of facial nerve (CN VII).

Blood Supply

Submental branch of the facial artery, and suprascapular branch of the thyrocervical trunk.

Function

• Aids facial expression by lowering the inferior lips.
• Depresses mandible.
• Tenses the skin of the anterior neck.
• Releases pressure of the skin on the subjacent veins.

Clinical relevance

• Dissimilar to other muscles of the body that lie deep to the subcutaneous tissue, the platysma is located within the subcutaneous tissue of the neck (superficial layer of the cervical fascia). Its superficial position means that surgical dissections of the neck must acknowledge the underlying neurovascular structures.
• Platysma can separate into rope-like bands, with irregular tension, causing the appearance of wrinkly skin on the neck. This is associated with the first signs of ageing of the neck, known as turkey neck. It occurs due to a decrease in muscle tone leading to thinning and shortening of the muscle.
• Platysma synkinesis can be a secondary complication of facial palsy. Common facial synkinesis, with synkinesis referring to simultaneous movement, creates abnormal synchronisation of facial movement. This occurrence results in involuntary facial movement happening during voluntary movement of a different facial muscle group. It can lead to static and dynamic asymmetry of the neck and of the inferior parts of the face. The condition may cause discomfort, aesthetic concerns and functional impairment.

Assessment

Platysma can be activated by asking the patient to forcefully depress and draw the lower lip laterally whilst maintaining the mandible in a position of slight depression.

Treatment

Trigger points (TrPs) in the platysma can result from or aggravated by acute or chronic overuse of the muscles, for example repeated expressions of disgust or horror, and TrPs in the sternocleidomastoid (SCM) and scalene muscles. TrPs in platysma may create a prickly pain over the mandible. The TrPs referral of platysma can overlap with those of SCM, masseter, temporalis, and medial pterygoid. Additionally, TrPs in platysma can be misdiagnosed as temporomandibular joint (TMJ) dysfunction. Most TrPs in platysma are regularly located over SCM.