Labiomental Fold Filler: Indication and Risks

The labiomental fold is the horizontal crease between the lower lip and the chin. A deep fold gives the lower third a tired or sad look, even in someone in a good mood. That is why it is a common concern, and why many practitioners fall into the trap of treating the fold on its own, when the cause lies in the chin, the muscle or the skin.

This content is a review of anatomy, indication and risks for the orofacial harmonization (HOF) professional in Brazil. It is not an injection protocol. Product, volume and approach are left to the judgment of the licensed professional, after assessment, in line with the rules of their professional council and the product's instructions for use.

Where does the depth of the fold come from?

The labiomental fold is a depression that follows the transition between the lower lip and the chin. Its look depends on several combined factors:

• Bone: a retruded chin (retrogenia) or one with little projection accentuates the fold by contrast.
• Fat and soft tissue: volume loss or ptosis of the chin tissue changes the depth.
• Muscles: the depressor anguli oris (DAO), the depressor labii inferioris and the mentalis act on the dynamics of the lower third.
• Skin: loss of collagen and elasticity deepens the crease.
• Teeth and occlusion: loss of support and bite pattern influence the profile.

The labiomental angle is the measurement that describes this fold in profile. A very closed or very open angle changes how the area reads. See also facial profile and pogonion for the bony base.

How does a projected or retruded chin change the decision?

The relationship between the chin and the lower lip defines the profile of the lower third. With a retruded chin, the fold looks deeper; with an already projected chin, filling the fold can accentuate the distortion. That is why the profile assessment comes before any gel: see retrognathic profile: assessment and profile changes with age.

For the chin, see chin filler, the Chin area and hyaluronic acid along the chin line. For the logic of choosing by area, see hyaluronic acid by area.

What is the role of the DAO muscle?

The DAO pulls the corner of the mouth down and, together with the other depressors, contributes to the sad look of the lower third. It acts on a different layer and at a different point of the fold, but it influences the dynamics of the area. The detailed discussion is in botulinum toxin in the depressor anguli oris and in marionette lines.

Which risks do you need to know?

The labiomental fold receives branches of the inferior labial artery and the submental artery, and the mental nerve exits the mental foramen, on the lateral side. Vascular occlusion is a possible complication, with the approach described in vascular occlusion in the chin and in vascular occlusion.

The most discussed risks:

1. Vascular occlusion, with ischemia of the lower lip or chin.
2. Irregularity and nodule, more visible in thin skin.
3. Tyndall effect, when the gel sits superficially (see Tyndall effect).
4. Swelling, more evident around the lower lip.
5. Paresthesia, from contact with the mental nerve (see mental nerve block, which also has its risks).
6. Asymmetry, from anatomical differences between the sides.
7. Artificial look, when the fold is "erased" and loses its natural transition.

How do you assess the patient before indicating treatment?

A history of cold sores is relevant, because trauma can reactivate the virus (see cold sores and filler). The assessment of the whole perioral area is in aging of the perioral region, and that of the lower third in lower third laxity: assessment.

How do you talk to the patient?

The patient usually points at the fold and asks to "take it away." The professional needs to explain that the fold is part of the anatomy, that the cause may lie in another structure, and that the plan may involve more than one area, with small volumes.

Avoid promising that the fold will be erased or that you will rejuvenate the face. Results vary, and the patient should know that the gel is absorbed over time (see real duration of hyaluronic acid in the face).

What Harmy shows

In Harmy, the Chin point lets you mark the ml and the intensity (Subtle, Moderate or Pronounced) and generate an illustrative projection from a frontal photo. The app has no specific point for the labiomental fold, and the frontal photo does not show the profile, which is what best describes the relationship between chin and fold. So the projection helps you talk about the chin as a whole, but it does not replace the profile assessment. None of this is a promise of results. In the app's "Full harmonization" shortcut, the chin comes in at 1.5 ml, Moderate intensity.

What if something does not go as planned?

For irregularity, a nodule or a bluish tone, hyaluronidase is an option when indicated (see dissolving filler: criteria for indication). For signs of vascular occlusion, follow the clinic's protocol, with the preparation described in emergency kit for the HOF practice. Follow-up and records follow clinical follow-up after HOF and post-procedure instructions.

In summary

The labiomental fold is rarely the isolated problem. Look at the chin, the muscle and the skin; preserve the natural transition; work with conservative volumes and be prepared for a complication. The safest decision is usually the most discreet one.