The platysma is a thin, broad muscle that extends from the upper chest to the lower jaw. It is a paired muscle, with one located on each side of the neck. The platysma is responsible for several functions related to facial expression and movement of the neck and shoulders.
Structure of Platysma muscle
- Origin: The platysma originates from the fascia covering the pectoralis muscle in the upper chest, and extends upwards and outwards to cover the front and sides of the neck.
- Insertion: The platysma inserts into the lower border of the mandible (jawbone) and the skin of the lower face and neck.
- Nerve supply: The platysma is innervated by the cervical branch of the facial nerve (CN VII).
- Actions: The platysma is responsible for several actions related to facial expression and movement of the neck and shoulders. It can contract to pull down the corners of the mouth, creating a grimacing or unhappy expression. It also helps to flex the neck and shoulders forward, and can assist in protracting the mandible (moving it forward).
Location
The platysma is located in the neck and upper chest region. It originates from the fascia covering the pectoralis muscle in the upper chest, and extends upwards and outwards to cover the front and sides of the neck. The platysma inserts into the lower border of the mandible (jawbone) and the skin of the lower face and neck. It is a paired muscle, with one located on each side of the neck.
Function
The platysma is a muscle responsible for several functions related to facial expression and movement of the neck and shoulders.
Facial expression
- The platysma can contract to pull down the corners of the mouth, creating a grimacing or unhappy expression.
- It can also assist in protracting the mandible (moving it forward), which can contribute to an open-mouth or surprised expression.
Neck and shoulder movement
- The platysma helps to flex the neck and shoulders forward.
- It can also assist in rotating the head to the side, by contracting on one side and relaxing on the other.
Maintaining neck shape and appearance
- The platysma helps to maintain the shape and contour of the neck.
- It is an important muscle for maintaining a youthful appearance, as it helps to prevent sagging and wrinkles in the neck and lower face.
Clinical significance
There are several clinical conditions that can affect the platysma muscle and its functions. Here are some examples:
Facial nerve paralysis
Facial nerve paralysis can result in weakness or paralysis of the muscles innervated by the facial nerve, including the platysma. This can lead to a lack of facial expression and difficulty with movements of the neck and shoulders.
Neck bands
As the platysma muscle ages, it can become weakened and sag, leading to the development of visible bands in the neck. These neck bands, also known as “turkey neck,” can be cosmetically undesirable and may be treated with surgical or non-surgical interventions such as Botox or fillers.
Trauma or surgery
Trauma to the neck or facial region, or surgery in these areas, can result in damage to the platysma muscle. This can lead to weakness or paralysis of the muscle and resultant functional deficits.
Platysmal banding
Platysmal banding refers to the visible vertical bands that can occur in the neck as a result of contraction of the platysma muscle. This can occur in individuals with hyperactive platysma muscles or with poor posture, and may be treated with exercises to strengthen the platysma and improve posture.
Overall, the platysma muscle is clinically significant due to its role in facial expression and movement of the neck and shoulders, as well as its impact on the appearance of the neck. Dysfunction of the platysma can result in functional deficits and cosmetic concerns.
