Pebble Chin Botox at a Sinnonhyeon Station Dermatology Clinic: Why Does the Chin Look Bumpy?

Does your chin look unusually bumpy in photos, or do you feel tension in your chin every time you close your mouth?

It often goes unnoticed in day-to-day life, but when you talk or press your lips together tightly, the skin on your chin can rise into small bumps, and suddenly it starts to bother you.

In these cases, you may wonder whether pebble chin Botox could help. In consultations at our Sinnonhyeon Station dermatology clinic, the first thing we look at is not how deep the wrinkles are, but how the chin muscle is being used.

This is because a chin that looks bumpy is not always just a skin issue.

Today, we'll walk through why the chin muscle tenses up, how Botox works, and when Botox alone may not be enough.

Why does the chin become bumpy?

There is a muscle at the chin called the mentalis, or chin muscle. When it contracts, it pulls the skin inward, which can make the surface look uneven and bumpy. This look is commonly called “pebble chin,” and because it looks like a walnut, it is also described as “walnut wrinkles.”

People with a short chin, or faces where the lips don't close comfortably, may rely more on the mentalis to close the mouth. Conversely, a protruding chin, or dental alignment that keeps the lips from meeting naturally, can cause similar tension.

Even without a clear skeletal problem, repeated habits such as pressing the lips together tightly, clenching the teeth, or breathing through the mouth can keep the chin muscle constantly tense.

What changes can you expect after Botox?

Chin Botox involves injecting a small amount of botulinum toxin into the overactive chin muscle to soften its strength. As the muscle's pull on the skin lessens, the bumpy texture that appears when you tense your chin can become noticeably smoother.

Changes usually begin to appear about 3 days to 1 week after treatment, and results tend to settle more firmly after about 1 to 2 weeks.

How long results last depends on each person's muscle use, the dose, and the treatment method, but they are often described as lasting around 3 to 4 months.

Are there reasons the results may feel weak?

Even with the same treatment, how the results feel can differ from person to person. If the dose was small relative to how developed the chin muscle is, or if the muscle moves differently on each side and the injection points were not refined enough, the change may feel less noticeable.

Another reason is structural.

In cases of a clearly receding chin, simply weakening the muscle will not dramatically change the overall shape of the chin.

In such cases, rather than repeating Botox alone, we also consider chin length, how far the chin projects, and how the lips close, and we may compare other options such as chin filler when needed.

If you have a pronounced receding chin and regularly use a lot of chin muscle to close your lips, a more careful approach is needed. In these cases, weakening the muscle too much can make it uncomfortable to close the lips, so it is better to assess your current chin structure and muscle use together rather than starting with a strong treatment from the outset.

Will more injections make the chin smoother?

That's not the case.

Because the small muscles of the chin are closely connected to the movement around the mouth, injecting beyond what is needed can make lip movement look unnatural.

Too little may produce only a weak effect, while too much can cause discomfort when closing the mouth or drinking.

That is why it's important not to apply a fixed dose across the board. Instead, the injection sites and amounts should be adjusted after checking how the chin muscle moves at rest and when the lips are closed.

If you have had Botox in other areas recently, it's also a good idea to tell your provider about your treatment history in advance. Frequent treatments at short intervals or regular use of large doses also call for consideration of toxin resistance.

Could the chin look even more unnatural after treatment?

In the early stages, the muscle's strength may not decrease evenly across the entire area, and only certain spots may appear raised.

This can look like a round “hard candy” bump, or make it feel as though a small dimple has formed on the chin. In many cases, it settles over time, and depending on the condition, the medical team may consider additional adjustments.

If the toxin affects the muscles around the mouth, the corners of the lips may look different from side to side, or drinking may feel awkward.

These effects are mostly temporary, which is exactly why the range of the chin muscle and facial movements should be carefully checked before treatment.

Can I go about my daily life right after the procedure?

Because it is an injection procedure, the recovery burden is relatively light. Redness, slight swelling, or bruising may appear at the injection sites, but these usually fade naturally over time.

Right after treatment, avoid pressing or rubbing your chin firmly. On the day of the procedure, it's best to skip activities that significantly increase blood flow, such as intense exercise or drinking alcohol. For a few days, it's also generally best to avoid strong heat, such as saunas or heat-based spa treatments.

Ultimately, what matters most is not the wrinkles but why the chin keeps tensing up. Not every bumpy chin is treated in the same way.

Muscle tension caused simply by habitual facial expressions requires a different approach from tension that persists because of chin length, bite (occlusion), or lip position.

Botox can help reduce excessive muscle contraction, but it does not change the bone structure itself.

So rather than deciding how much to inject first, it's better to check how the chin moves at rest and when the mouth is closed.

A natural-looking chin doesn't come from eliminating all muscle activity. It starts with reducing excess tension and helping the expression look more relaxed.