Chin Dimpling and the Mentalis Muscle

A dimpled, pebbly or "orange-peel" chin is usually caused by the mentalis, a small muscle in the chin that tightens and bunches the skin over it. Small doses of neuromodulator can relax this muscle so the skin looks smoother for a few months. When the chin is also short or lacks bony support, a hyaluronic acid filler is sometimes added to give the muscle less work to do.

What the mentalis does

The mentalis is a paired muscle that runs from the lower jaw, just below the lower front teeth, down into the skin of the chin. When it contracts, it raises the chin skin and pushes the lower lip up and out. You use it when you pout, express doubt or hold back tears.

Because the muscle attaches directly into the skin, strong contractions pull the surface into small pits and bumps. This is the texture people describe as cobblestone, golf-ball or orange-peel chin. Some people also develop a horizontal crease across the chin, called the mental crease, just under the lower lip.

Why it becomes overactive

Chin dimpling is common and often has more than one cause:

• Lip strain: people whose lips do not meet easily at rest, often because of the bite or tooth position, may use the mentalis constantly to close the mouth.
• A small or receding chin: with less bone underneath, the muscle has less support and its bunching shows more.
• Ageing: the chin pad and bone gradually lose volume, and the skin thins, so the dimpling becomes more obvious.
• Habit: some people tense the chin when concentrating, speaking or feeling stressed.
• Dental changes: missing teeth or changes in the lower jaw can alter how the lips sit.

If lip strain from a bite issue is the main driver, it is worth talking to your dentist or orthodontist. Injections can soften the look but will not change the underlying cause.

How neuromodulator treatment works

A physician places a small amount of botulinum toxin type A into the mentalis, usually through one or two injection points low on the chin, kept close to the midline and well below the lip. The muscle relaxes partially, and the skin above it lies flatter.

The effect typically appears over 3 to 14 days and lasts around three to four months. Some people find that the habit of tensing the chin eases while the muscle is relaxed. For a general explanation of the medicine, see What Is a Neuromodulator?

The main risk: affecting the lower lip

The mentalis sits close to the muscles that pull the lower lip down and shape the smile. If the medicine is injected too high or spreads sideways, it can weaken the depressor labii inferioris or the orbicularis oris around the mouth. People may then notice:

• A lopsided smile or a lower lip that does not move evenly
• Difficulty pronouncing some sounds, such as "p", "b" or "f"
• Dribbling when drinking, or trouble sipping through a straw
• A feeling that the lower lip is loose or heavy

These effects are temporary but can take several weeks to resolve. For this reason, chin treatment is usually started with a cautious dose. People who rely on precise lip control, such as wind instrument players or professional speakers, should mention this at consultation.

When filler is added for support

For some people, relaxing the muscle alone leaves the chin looking flat or short. Hyaluronic acid filler placed deep along the chin bone can add projection or length, which may reduce how hard the mentalis has to work and soften the crease beneath the lip. Filler and neuromodulator are sometimes used together, at the same visit or a few weeks apart.

Filler brings its own risks, including swelling, bruising, lumps, infection and, rarely, blockage of a blood vessel. Our article on jawline and chin filler covers chin support in more detail, and filler and vascular safety explains how injectors reduce the most serious risk.

Who should not have this treatment, or should wait

Chin injections are generally avoided or postponed if you:

• Are pregnant or breastfeeding
• Have an infection, cold sore or active acne on or around the chin
• Have a neuromuscular condition such as myasthenia gravis or Lambert-Eaton syndrome
• Have had a reaction to a botulinum toxin product or to hyaluronic acid filler
• Are about to have dental work involving the lower front teeth, in which case timing should be discussed

Tell your physician about all medicines and supplements, including blood thinners. Do not stop prescribed medicines on your own to reduce bruising.

Other side effects

Most people have only mild tenderness, redness or small bumps for a short time. Bruising is possible. Rarely, the result is uneven and one side of the chin looks smoother than the other. A review about two weeks after treatment helps your physician check the outcome and plan any change for the next visit. Some people get a mild headache on the day of treatment. As with any neuromodulator, the effect cannot be reversed once it sets in, so any unwanted change simply has to wear off over the following weeks. This is the main reason a small first dose is preferred, with the option to add more at a later visit if the softening is not enough.

Frequently asked questions

Is a dimpled chin a medical problem?

No. It is a normal pattern of muscle activity. Treatment is a personal choice, and many people never feel the need for it.

Will it change my natural chin cleft?

A true cleft chin comes from the structure of the bone and soft tissue, not the muscle. A neuromodulator usually does not remove it, although it may soften surrounding texture.

Can the crease under my lower lip be treated too?

Sometimes. Relaxing the mentalis can soften it, and a small amount of filler may help a crease that remains at rest. Deep creases may only partly improve.

Is it right for you?

The chin is a small area with close neighbours, so planning matters as much as technique. At HealthPark Medical Aesthetics, a consultation looks at your chin, lips and bite together, explains the risks, and helps you decide whether neuromodulator, filler, a dental opinion or no treatment fits your goals.