The platysma is a broad, thin superficial muscle of the neck covering the anterior triangle from the chest to the lower face, with fibres running nearly vertically from the pectoral fascia to the mandible and facial skin. It is a remnant of the panniculus carnosus, the subcutaneous muscle sheet present in many mammals for skin twitching. In humans it contributes to neck tension, facial expression in extreme emotion, and the platysmal bands that become prominent in neck ageing.
| Origin | Fascia overlying the pectoralis major and deltoid |
|---|---|
| Insertion | Inferior border of the mandible and facial skin overlying the lower face and cheek |
| Nerve Supply | Cervical branch of the facial nerve (CN VII) |
| Blood Supply | Submental and suprascapular arteries |
| Actions | Tenses the skin of the anterior neck; Depresses the mandible and lower lip; Draws the corners of the mouth downward in extreme expressions of horror or anguish |
|---|
The platysmal bands seen in neck ageing and in extreme neck tension represent the medial platysma edges separated from each other at the midline, creating the corded appearance that responds to botulinum toxin injection (Nefertiti lift) or surgical platysmaplasty during facelift procedures.
Platysmal banding is the most common age-related neck change treated surgically, addressed by suturing the medial platysma edges together (platysmaplasty) during a facelift to recreate the cervicomental angle. Botulinum toxin injection into the platysmal bands (Nefertiti lift) is a non-surgical alternative producing temporary improvement. The platysma is divided during neck dissection with careful preservation of the marginal mandibular nerve that runs on its deep surface.
The platysma is palpable as thin sheet-like muscle over the anterior neck that contracts visibly during forced downward depression of the lower jaw and lip, the platysmal bands becoming prominent with clenching.
Separation and prominence of medial platysma edges with ageing producing vertical neck bands treated with botulinum toxin injection or surgical platysmaplasty during facelift procedures.
