Mouth-corner Botox and nostril Botox — before you look into them in Daegu
Searches for these two have risen sharply. The names are familiar, but which muscle each one acts on, and what it actually does, is rarely explained. There are no prices in this column. Instead we have written down what these two treatments can and cannot do, and the things you should hear before going ahead.
The short answer
Mouth-corner Botox reduces the pull of the muscle that draws the corner of the mouth downward (the depressor anguli oris), so a downturned mouth turns down less; nostril Botox reduces the movement that flares the nostrils when you smile. Neither area appears on the list of approved indications in Korea, so both are off-label use. The effect usually appears in 3–7 days and returns over 3–4 months, and neither the size of the nostrils, which is set by bone and cartilage, nor skin laxity itself changes. When Miso Clinic looks at these two areas, we first separate whether the whole face has descended or whether the problem is only muscle movement, and where it is not a muscle problem we do not recommend Botox. Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, in front of Exit 1 of Kyungpook National University Hospital Station. +82-53-428-2700, weekdays 11:00–19:00 · Saturday 10:00–16:00 (no lunch break), closed Sundays and public holidays.
Which muscle does mouth-corner Botox act on, and what does it do?
A muscle called the depressor anguli oris (DAO) runs from either side of the mouth corner down toward the lower jaw. As the name says, its job is to pull the corner of the mouth downward. With age, or with a habit of tensing the mouth, this muscle settles into pulling without rest. The result is the impression people describe as “looking angry even at rest”.
| Item | Detail |
|---|---|
| What it acts on | The pull of the muscle that draws the mouth corner downward |
| Change you can expect | At rest, the mouth line looks less downturned |
| What it does not act on | Sagging caused by descended cheeks, the trough of a set line beside the mouth, skin laxity |
| When it appears | 3–7 days, peak around two weeks |
| When it returns | Generally 3–4 months (no data measured for this area alone) |
| Korean approval | Not on the list of approved indications — off-label |
If the reason the mouth corner has come down is not the muscle but the cheek having descended, Botox changes almost nothing. In that case jawline sagging or the nasolabial fold is the conversation to have first.
Does nostril Botox make the nostrils smaller?
This is the question we are asked most. To answer it plainly: the size of the nostrils themselves is set by bone, cartilage and skin thickness, so Botox does not reduce it. What Botox can reach is only the movement that flares the nostrils when you smile or speak. If the shape at rest is what concerns you, this treatment is not the answer.
| The concern | Does Botox change it? | Why |
|---|---|---|
| My nostrils flare a lot when I smile | The movement can be reduced | Muscle movement is the cause |
| My nostrils are wide even at rest | Almost unchanged | Cartilage and skin thickness set it |
| My bridge is low, so they look relatively wide | Unchanged | A question of height |
| A lot of gum shows when I smile | A different muscle | The muscle that lifts the upper lip |
Around the nostrils, the muscles that build a smile overlap closely. A slightly excessive dose, or a position slightly off, can make the smile look unnatural or leave the two sides different. That is why we handle this area cautiously.
What does “use outside the approved range” mean?
The approved labelling of botulinum toxin products in Korea lists the areas they may be used on, such as glabellar lines and crow’s feet. The depressor anguli oris and the nostrils are not on that list. So both of these treatments are use outside the approved range (off-label).
- Off-label is not prohibited. It sits within the scope of practice a physician judges, explains, and obtains consent for.
- But it also means the data is not as thick as for the approved areas. Figures for effect and duration have not been compiled area by area.
- So guidance that states flatly “it lasts X months” should be heard with care.
Miso Clinic explains these two areas as off-label before judging. Telling you first whether something is inside or outside the approved range is the same principle as how to read an approval number.
Cases where we do not recommend it
| The case | Judgement | Reason |
|---|---|---|
| Sagging from descended cheeks or jawline | Not recommended | A structural problem, not a muscle one |
| Nostril size at rest | Not recommended | Cartilage and skin thickness set it |
| Work that depends on speaking clearly | With caution | The perioral muscles are also used in articulation |
| Pregnancy or breastfeeding | Not performed | No safety data |
| Neuromuscular disease, or medication for one | Not performed | Muscle weakening may be amplified |
| A previous unnatural expression in the same area | With caution | Dose and position must be redesigned |
The area around the mouth is the most sensitive place on the face. A small amount of spread into a neighbouring muscle can change the shape of a smile or, rarely, make speech briefly unclear. These changes also resolve with time, but you have to wait some weeks for them to. That is why starting with a small dose is the safer approach.
Summary
What is established
- Botulinum toxin temporarily reduces the signal reaching a muscle, and it returns with time
- The depressor anguli oris and the nostril muscles sit immediately beside the muscles used for smiling and articulation
- Neither area is on the list of approved indications in Korea
What we could not find
- A study measuring effect and duration for the mouth corner or the nostrils in isolation
- The primary approved labelling text for individual products
- A comparative study of which dose is best
Mouth-corner and nostril Botox: frequently asked questions
What is mouth-corner Botox?
Mouth-corner Botox places a small amount of botulinum toxin into the depressor anguli oris, the muscle that pulls the corner of the mouth downward, to reduce its pull temporarily. The aim is for the mouth line to look less downturned at rest; it does not address sagging caused by descended cheeks.
Will nostril Botox make my nostrils smaller?
The size of the nostrils themselves is set by bone, cartilage and skin thickness, so Botox does not reduce it. The only thing that can change is the movement that flares the nostrils when you smile or speak.
How long does mouth-corner Botox last?
Across treatments of the facial expression muscles generally, botulinum toxin is reported to appear in 3–7 days, peak at around two weeks and return over 3–4 months. We could not find a study that measured duration for the mouth corner in isolation.
Is mouth-corner Botox an approved treatment?
The list of approved indications in Korea names areas such as glabellar lines; the depressor anguli oris and the nostrils are not on it. It is use outside the approved range (off-label), which is not prohibited but does mean the data is not as thick as for the approved areas.
What are the side effects of mouth-corner Botox?
If it spreads into a neighbouring muscle, the smile can look unnatural or the two sides can differ, and rarely speech can be briefly unclear. Most of this resolves with time, but you have to wait some weeks, so starting with a small dose is the safer approach.
How can I tell whether my mouth corner is down because of muscle or because of sagging?
In front of a mirror, lift your cheek slightly with your hand. If the mouth line rises with it, the descended cheek is the larger influence and Botox will not change much. If the mouth corner is pulled down only when you make an expression, it is the muscle. The precise distinction is made in consultation.
Should I have Botox or filler first?
Problems that appear on movement belong to Botox; problems that come from loss of volume belong to filler. Around the mouth the two are often mixed, so we first separate which is the larger cause.
Where can I have a consultation about mouth-corner Botox in Daegu?
Miso Clinic is at 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, in front of Exit 1 of Kyungpook National University Hospital Station, and can be reached on +82-53-428-2700. We see patients weekdays 11:00–19:00 and Saturday 10:00–16:00, and are closed Sundays and public holidays. Fees vary with the area and the dose, so they are given by phone or at an in-person consultation.
Read next
Product pages
Other Miso Clinic treatments for wrinkles and sagging: Density · XERF · Oligio KISS · GOURI
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. The criteria for treatment and the injection design are written exactly as we use them, and where we could not find data, we have said that we could not find any.
| Medical director | Lee Chi-Hak, MD |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea · Exit 1, Kyungpook National University Hospital Station |
| Phone | +82-53-428-2700 |
| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 (no lunch break) / Closed Sundays and public holidays |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- How botulinum toxin works — botulinum toxin type A blocks the release of acetylcholine at the nerve terminal, temporarily reducing the pull of that muscle. The muscle is not removed; the signal is interrupted for a time and returns.
- Approved indications in Korea and off-label use — Korean approvals are written product by product for specific areas such as glabellar lines and crow’s feet, and the depressor anguli oris and the nostrils are not on that list. Use outside the approved range (off-label) is not prohibited; it is carried out under a physician’s judgement and explanation. We could not obtain the primary approved labelling text for individual products.
- Anatomy of the depressor anguli oris and the nostril muscles — the depressor anguli oris (DAO) attaches from the border of the lower jaw to the corner of the mouth and pulls that corner downward. Flaring of the nostrils involves the alar part of the nasalis and the levator labii superioris alaeque nasi. Both areas sit immediately beside the muscles used for smiling and articulation.
- Onset and duration — botulinum toxin is generally reported to appear 3–7 days after treatment, peak at around two weeks and return over 3–4 months across treatments of the facial expression muscles. We could not find a study that measured duration for the mouth corner or the nostrils in isolation.
- Approval numbers and advertising review numbers — MFDS medical device approval and prior review of medical advertising are separate procedures. For example, “Combination general electrosurgical unit-2024-16-054” on XERF material is an advertising prior-review mark.
- Law on medical advertising — Medical Service Act Article 56(2), which prohibits advertising using accounts of treatment experience, comparison with other medical institutions, and superlative expressions.
- Fees and patient inducement — Medical Service Act Article 45 (notification of non-covered treatment fees), Article 27(3) (prohibition of inducing patients for profit) and Article 56(2) (prohibited matters in medical advertising). This is why no price or discount appears in this column.
- Miso Clinic clinical protocols — criteria for indications, design by area, and the explanation and consent process before treatment. The source of the sentences marked “clinical judgement” in this column.
Everything in this column is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.
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