Hyaluronic acid in the chin line and submental area: limits

The chin is the anchor of the lower third: when it is under-projected, the profile looks recessed, the neck looks "closer" and the chin line loses definition. That is why requests for hyaluronic acid in the chin are common. The submental area, the transition between the chin and the neck, enters the conversation because many patients mistake a projection concern for a fat or laxity concern.

This page is about limits. It does not teach injection technique: it guides how to read the case, the risks and the planning pitfalls. Product, volume and approach are at the discretion of the licensed professional, according to the rules of their professional council in Brazil.

What does gel actually do in the chin?

Hyaluronic acid delivers volume and, depending on the product's properties, support. In the chin this translates into three possible effects:

• increase the anterior projection, when the pogonion is recessed;
• change the height and width of the chin, to harmonize proportions;
• reinforce the definition of the chin line, together with the jawline.

What it does not do: it does not remove submental fat, does not tighten the platysma, does not reposition bone and does not correct significant skin laxity. Promising any of this to the patient is the shortest route to dissatisfaction.

How to assess before recommending?

Assessment starts with the profile, not the isolated area. Look at the patient from the side, with the head in a natural position (see standardized clinical photography), and answer the questions in order.

1. Is the chin truly recessed relative to the rest of the profile? See retrogenia and retrognathic profile: assessment.
2. Is the cervicomental angle obtuse because of fat, skin or the position of the hyoid bone?
3. Is the mentolabial angle shallow or deep, and does the lower lip follow?
4. Is there a double chin from submental fat, and is it compartmentalized or diffuse?
5. Is there a chin or jaw asymmetry that gel would accentuate?

What is the pitfall of the submental area?

The submental area is the region between the tip of the chin and the curve of the neck, and it holds submental fat, subplatysmal fat and the platysma. Filling this area with gel to "disguise" the double chin tends to add volume where it is already full, producing a heavy look. The practical literature describes more problems when the indication is mistaken than when the technique is imperfect.

When the patient asks for help with the "double chin", the correct reasoning is to separate the cause. Sometimes gel in the chin projection improves the visual relationship, because the chin moves forward and the submental area looks slimmer. But the improvement is indirect, and the patient needs to understand that beforehand.

Anatomy that matters in the area

A few review points:

• the mental nerve exits through the mental foramen and supplies the lower lip and chin, and injury to it causes paresthesia;
• the submental artery, a branch of the facial artery, runs through the submental region;
• the inferior labial artery runs close to the lower lip and can connect to the chin's circulation;
• the mentalis muscle moves the tip of the chin and affects gel stability;
• the skin and subcutaneous tissue of the submental area are thinner on one side than the other, depending on the fat.

Alongside, the anatomical diagram shows the submental artery. For the vascular risk of the chin, read vascular occlusion in the chin.

What are the specific risks?

Two situations deserve a reminder. The first is excess projection: the "witch's chin" or an overly forward chin disharmonizes the profile and is hard to reverse without dissolving. The second is growing expectation: the patient who likes the first result tends to ask for more, and it is up to the professional to hold back when the proportion stops being natural. See also overcorrected chin as an example of the "less is more" principle.

How to talk with the patient?

Consultation checklist

How does it evolve?

For the clinical review, see clinical follow-up visit and post-procedure instructions.

Using the app as a planning aid

In Harmy, the Chin point lets you simulate chin projection, and Jawline simulates the line of the jaw. It is useful for showing the patient what a moderate volume might suggest and for avoiding a discussion in the dark. The simulation is illustrative, uses only the frontal photo and does not replace profile assessment.

Myth or fact

To keep in mind

The chin and submental area require you to see the face in profile and in layers before thinking about gel. Hyaluronic acid has a clear role in chin projection and definition and a limited role in the double chin. Document the cause, the alternatives offered and the consent. For the overall picture, see hyaluronic acid by area, chin filler and the chin area.