Neck rejuvenation: what changes in the neck?

Why the neck is discussed separately from the face

The neck is a continuation of the face, but it does not age at the same rate or in the same way as the face. The reason for looking at it separately is not an aesthetic preference but a structural difference.

The skin of the neck is thin and exposed all day. Research also emphasises that the neck is prone to ageing and often exposed to the sun, and that this is why it plays a decisive part in overall appearance.

Changes in the neck cannot be reduced to a single cause. Loosening of the platysma muscle (the thin, flat muscle that covers the front of the neck), redistribution of fat, bone remodelling and a decline in skin quality all play a part together. According to research, this picture varies not only from person to person but also between populations: a build-up of volume more often stands out in people of African and Asian descent, while laxity and banding more often stand out in people of European descent.

These four changes do not progress at the same time or to the same degree. The first step in understanding what has changed in your neck is to work out which of them is leading.

Platysma: the muscle that links the face and neck

At the front of the neck, just beneath the skin, lies a thin layer of muscle: the platysma. This muscle covers the whole neck and the lower part of the face; in other words, it is a single structure that starts in the neck and ends in the face. This is the anatomical reason why the neck behaves separately from the face yet remains connected to it.

How the two sides of the muscle meet in the midline is not the same in everyone. Research reports that in Korean patients, a pattern in which the platysma fibres from both sides cross over in the midline is seen in 85% of cases. This variation is one reason why the appearance under the chin cannot be interpreted in the same way for everyone.

The fact that the muscle lies close to the surface has two consequences. First, when the muscle contracts, the movement beneath the skin can be seen from the outside. Second, any treatment in this area is close to the structures responsible for swallowing and producing the voice. Inadequate knowledge of the anatomy can lead to side effects such as difficulty swallowing (dysphagia), voice changes and weakness in the neck muscles. To reduce the risk of these side effects, researchers recommend anatomically safe injection points.

How platysma bands develop

Over time, the platysma loosens, and when it contracts it stands out as vertical bands at the front of the neck. The medical term for this is platysma prominence. Research shows that this is a common age-related finding with two separate consequences: visible bands in the neck and loss of definition along the jawline.

The problem here is not excess skin but the muscle itself. This is why this finding points to treatments that reduce the muscle’s activity. In an analysis that pooled three randomised controlled trials (trials in which participants are randomly assigned to groups), botulinum toxin, often called Botox®, gave a significant improvement compared with placebo (a dummy treatment) in both doctors’ and patients’ assessments. The rate of treatment-related adverse effects did not differ from that in the placebo group, and most of the reported effects were mild and temporary.

Here is how to tell them apart: if a band appears only when the muscle contracts, the problem lies in the muscle. If the band is also visible at rest, skin laxity or tissue that has built up underneath is also involved, and a single treatment is not enough for this picture.

For botulinum toxin treatments in the lower face and neck, there is not yet a shared protocol for the treatment area, the dose or how results are measured. More studies are needed so that the effect can be measured objectively. For this reason, it would not be accurate to give a general figure for dose or duration.

What horizontal neck lines show

Lines that run across the front of the neck are popularly known as ‘rings of Venus’ or ‘necklace lines’; the medical term is horizontal or transverse neck lines. They are a different finding from platysma bands: bands are vertical and relate to the muscle, while horizontal lines run across the neck and lie within the skin itself.

It is not accurate to link these lines only to ageing. Research shows that horizontal neck lines are seen in younger age groups as well as in older people. In other words, the presence of these lines is not, on its own, a sign of age.

In an analysis that pooled eleven studies, hyaluronic acid (HA) fillers gave a significant improvement in this area in wrinkle severity and on the global aesthetic improvement scale; device-based measurements also showed improvements in hydration, elasticity and the structure of the dermis (the middle layer of the skin). The limitations were also clearly stated: the retreatment rate within 12 months was reported as 50%, and the complication rate as 14%. The reported complications were mild and temporary. The analysis itself is rated as level IV evidence.

As well as with hyaluronic acid gels, improvements in wrinkles and skin laxity in the same area have also been seen with poly-L-lactic acid (PLLA) and calcium hydroxylapatite (CaHA), which stimulate collagen production. However, these studies assessed results using different measures, participant numbers were small and long-term evidence is limited.

Submental fullness and the cervicomental angle

Fullness under the chin (submental fullness) does not come from a single tissue. Research emphasises that it depends on many factors and that the treatment plan needs to be tailored to the person’s anatomical differences, the amount of fat and the type of platysma.

The layers under the chin are, in order: fat lying beneath the skin and above the platysma; a separate fat pad beneath the platysma; the submandibular gland (the salivary gland under the jaw) and the digastric muscle (a muscle located under the chin). Research on neck lift surgery has reported that the structures most often modified during the operation are the submandibular gland, the digastric muscles and the fat beneath the platysma. This shows that fullness under the chin is not always just surface fat.

Age-related bone remodelling also contributes to this picture: the line under the chin is shaped not only by the soft tissues but also by the bony framework that supports them. The U-shaped bone that hangs at the front of the neck (the hyoid bone) is part of this framework.

The cervicomental angle is the angle between the area under the chin and the front of the neck. All of the structures listed above contribute to this angle; the angle itself is not a cause but a result. This is why a ‘double chin’ does not correspond to a single condition, and which layer is most prominent can only be determined at a consultation.

Skin quality is a separate dimension

Laxity and skin quality are not the same thing. In one neck, the skin may be firm but dull; in another, skin quality may be good while the tissue has moved downwards. These two dimensions are assessed separately.

In injectable rejuvenation of the neck, décolletage and hands, treatments such as mesotherapy (an injection technique that delivers small amounts of active ingredients into the skin) and microneedling are also used alongside fillers to improve skin quality. However, the international consensus guidelines for mesotherapy openly acknowledge that the field long lacked a shared, evidence-based standard; the guidelines aim to close this gap, but higher-quality research is still needed.

Here, too, it helps to know the limits. An analysis of the effect of hyaluronic acid injections on skin ageing found significant improvements in hydration and radiance measurements; however, no significant change was found in elasticity or in the melanin index (melanin is the pigment that gives skin its colour). The researchers state that more research is needed.

This does not mean that treatments for skin quality do not work; it shows what can and cannot be measured. With treatments like these, you should base your expectations on hydration and appearance, not on the tissue being lifted.

What a thread lift does for sagging

A thread lift works not by heat or by adding volume, but by repositioning tissue. The thread picks up loosened tissue where it is, moves it towards a fixed point and holds it there.

Two things are decisive in this method. The first is the thread itself. Lifting threads form a separate class from conventional sutures, and they also differ from one another in their composition and mechanical behaviour. When choosing a thread, how long it lasts is not the only criterion.

The second is the point where the thread is anchored. This point determines both safety and the result: anchoring the thread to the deep fascia (a thin sheet of connective tissue that surrounds the muscles) below the angle of the jaw keeps it away from structures such as the great auricular nerve and the parotid gland (a salivary gland in front of the ear). It has been reported that placing the thread from the inside outwards increases the pull at the midline under the chin, and that working under ultrasound guidance improves accuracy.

A thread lift is considered when tissue has shifted downwards. How far tissue can be moved depends less on the type of thread than on the condition of the tissue itself and on the anchoring point. For this reason, it would not be accurate to claim a general duration for any type of thread.

Which findings point to which type of treatment

The choice starts with the finding, not the treatment. Research on non-surgical neck rejuvenation distinguishes the patterns as follows.

If there is little skin laxity but platysma bands appear when the muscle contracts, botulinum toxin injections are considered. If the skin is mildly or moderately loose, heat-based treatments such as focused ultrasound (HIFU) and microneedling radiofrequency (RF) are considered.

If marked sun damage is present together with laxity, fractional ablative lasers (lasers that remove many tiny areas of skin in a controlled way) are considered. If the main issue is fat under the chin lying above the platysma, treatments that target fat tissue are considered; these include options such as percutaneous radiofrequency (delivered through the skin), injection lipolysis and fat reduction by cooling.

In addition, muscle-relaxing injections (neuromodulators), hyaluronic acid fillers, fillers that stimulate collagen production (biostimulators), fat-dissolving injections (lipolytic agents) and energy-based tightening are among the options that can be used when they are planned to suit the anatomy. Research stresses that the area should be assessed as a whole.

In most necks, these patterns do not occur on their own; they overlap. These distinctions offer guidance, but which pattern is most prominent in your neck can only be determined at a consultation.

Where the line for surgery is drawn

None of the non-surgical treatments described here is a substitute for surgery; research also makes this clear.

Treatments such as surgical lifting and platysma myotomy (surgically cutting the platysma muscle) are effective. However, they carry a higher risk, a longer recovery period and a higher cost. Non-surgical treatments have a place within this picture as one of the options.

In research on neck lift operations that reach the deeper layers (deep-plane neck lifts), the line is even clearer. In the ageing neck, soft-tissue laxity increases and the structures in the neck shift position; because the response to non-surgical procedures varies, surgical solutions are needed. The structures reached in these operations are the submandibular gland, the digastric muscles and the fat beneath the platysma. These three structures are not in the layers that injections or threads can reach.

Surgery has its own risks too: in studies covering more than 8,000 patients, reported rates were 0.2–12% for nerve paralysis and 0.2–4% for haematoma (a collection of blood under the skin); patient satisfaction was 81.6–98.6%.

In short, if the fullness comes from beneath the platysma or from the salivary gland, or if excess skin is the main issue, non-surgical treatments will not meet expectations. This distinction is made at a consultation.

The limits of the evidence in this area

The neck has not been researched as thoroughly as the face. Research on hyaluronic acid fillers for horizontal neck lines clearly shows that effectiveness, safety and treatment standards in this area have not been studied enough. This does not mean the treatments do not work; it means there is not yet a shared language for measuring results.

In studies on fillers and collagen stimulators, the outcome measures differ from one another, participant numbers are small and long-term evidence is limited; for this reason, firm conclusions cannot be drawn. The situation is similar for botulinum toxin treatments in the lower face and neck: consistent, objective measures need to be established so that the effect can be measured accurately.

The international consensus guidelines for mesotherapy also state that their aim is to move from practice based on personal experience to evidence-based practice, and stress that higher-quality research is still needed.

For this reason, it would not be accurate to give a general figure for how long results last, the number of sessions or the success rate for any treatment. The figures in the research do not agree with one another; the figures that apply to you can only be discussed at a consultation.

Treatments offered here

At the clinic, the treatments offered for the neck are botulinum toxin, mesotherapy, hyaluronic acid fillers, collagen-stimulating fillers and thread lifts using dissolvable threads.

Which of these may be considered is assessed at a consultation, based on which of the findings described above is most prominent in your case. Understanding what has changed in your neck makes the decision easier; the decision itself is yours.