The neck in harmonization: platysma, lines and limits

The neck is the area that gives away age the most when the face has been treated and the neck has not. Thin skin, few sebaceous glands, sun exposure and constant flexion movement make horizontal lines, laxity and platysma bands appear early. In orofacial harmonization, it enters the plan as a continuation of the lower third: the sharpness of the jaw line depends as much on the jaw as on the neck right below it.

Because it is an area of delicate skin and important deep structures, the neck is also one of the regions where you most need to know the limits of injectables. This text covers the anatomy, the concerns, the options used and the risks, at a review level.

What are the anatomical boundaries of the neck in HOF?

For aesthetic purposes, the region is usually divided into:

• Upper: the lower border of the mandible, where the neck continues into the jawline.
• Submental: the area below the chin, where the fat of the double chin accumulates.
• Anterior: the front of the neck, where platysma bands and horizontal lines appear.
• Lateral: the sides, up to the edge of the sternocleidomastoid muscle.
• Lower: the transition to the décolletage, at the level of the clavicles.

Layers and muscles

Under the thin skin lies the subcutaneous tissue, with a variable amount of fat, and then the platysma, a broad, thin muscle that rises from the chest to the mandible and continues with the SMAS of the face. When it contracts, it tenses the skin and pulls the lower third downward. Beneath the platysma are the subplatysmal fat, the submandibular glands, the suprahyoid and infrahyoid muscles, the larynx and the thyroid.

Vessels and nerves to watch

• External jugular vein, superficial, which crosses the sternocleidomastoid and is visible in many patients.
• Facial artery and vein, which cross the border of the mandible in front of the masseter.
• Marginal mandibular branch of the facial nerve, near the mandibular border, responsible for lower lip movements.
• Cervical branch of the facial nerve, which innervates the platysma.
• Great vessels of the neck (carotids and internal jugulars), deep, protected by the sternocleidomastoid.
• Swallowing and phonation muscles, deep to the platysma, which toxin must not reach.

Why does the neck age?

In practice, each patient's neck combines these components in different proportions. The assessment defines which one is the main concern, because each responds to a different option.

What do patients usually ask for?

• "My neck has these lines that look like necklaces."
• "I have these cords on my neck when I talk."
• "I'd like a firmer neck, the skin is sagging."
• "I have a double chin even though I'm thin."
• "I had my face done, but my neck gives away my age."

Assess from the front, in profile, and with the neck in slight extension and flexion. Ask the patient to contract the neck (like making a grimace showing the lower teeth) to see the bands. Observe the angle between the neck and the jaw in profile.

What options are used on the neck?

Biostimulator on the neck

It is one of the fastest-growing searches. Calcium hydroxylapatite and poly-L-lactic acid are the most cited classes. In the thin skin of the neck, dilution, distribution and volume are decisive to avoid nodules, and the indication must consider what each product's registration covers. The overview of the class is in biostimulators, overview, and planning integrated with the face is in full face biostimulator.

Skinbooster on the neck

Indicated when the concern is texture, dehydration and fine lines. The effect is subtle, generally with more than one session. Hyaluronic acid products with high and low molecular weight complexes are one of the options in the class; see hybrid hyaluronic acid.

PDO threads on the neck

Absorbable thread lifts can be used in mild laxity, with the expectation of a subtle, temporary effect. In very lax skin, the result tends to disappoint, and surgery is the honest conversation.

Precautions, contraindications and complications

General contraindications: active infection in the area, pregnancy and breastfeeding, uncontrolled autoimmune disease, allergy to the components and unrealistic expectations. Investigate thyroid disease, prior neck surgery and use of medications that increase bleeding.

Complications reported in the region:

• Swelling, bruising and ecchymosis, common because of the thin skin and superficial vascularization.
• Nodules and irregularities, especially with biostimulators in an inadequate plane or distribution. See nodules after biostimulator.
• Tyndall effect and lumps with superficial hyaluronic acid in the lines.
• Asymmetry and irregularity with threads.
• With toxin: difficulty swallowing, voice changes and weakness of the neck muscles, when the product reaches deep planes.

When is the neck not a candidate for injectables?

• Significant excess skin, with hanging folds.
• Bulky subplatysmal fat, which does not change when the skin is pinched.
• Very pronounced bands at rest, with associated laxity.
• Cervicomental angle blunted by a low hyoid bone position or prominent submandibular glands.
• A patient who expects surgical results from an injectable.

In these cases, referral for surgical assessment is the best course, and it can be combined with treatment of the face. In older patients, see also HOF in patients over 50.

How does the neck appear in Harmy?

How to talk to the patient about the neck

The neck is the area where the gap between expectation and what injectables deliver tends to be largest. Separate the concerns (lines, bands, laxity, double chin) and say, for each one, what is possible.

Agree on the plan in stages, record everything with photos and make clear that the results are subtle and need maintenance.