Home / Skin Concerns / Square Jaw
Skin Concerns
Square Jaw Slimming in Seoul with Jaw Botox
Quick answer
A square jaw caused by enlarged masseter muscles is most effectively softened with jaw (masseter) Botox, which gradually slims the lower face over four to eight weeks without surgery. At The Heal in Jamsil, Seoul, a board-certified dermatologist checks whether muscle, fat or bone shapes your jaw before treating. The injection takes minutes with no downtime, and results vary. Ask us on KakaoTalk about same-day treatment.
Medically reviewed by Dr. Yang Jeong-hwa , board-certified dermatologist · Updated October 2026
Best options
Masseter Botox
Sessions
Every 4–6 months
Downtime
None
Timeline
4–8 weeks
What makes a jaw look square?
A square or wide jaw is determined by three main factors:
- Masseter muscle size: the chewing muscle at the angle of the jaw can enlarge with clenching, teeth grinding (bruxism) or frequent gum chewing.
- Bone structure: a wide or angular mandible is genetic and cannot be changed with injections.
- Fat and skin: lower-face fat or sagging can blur the jawline and make the face look wider.
In many people, especially those who clench, the masseter is the main contributor, which is good news because it responds well to non-surgical treatment.
How a dermatologist assesses your jaw
Dr. Yang asks you to clench and relax while she feels the masseter and observes how much it bulges. She also examines the bone angle, the amount of lower-face fat, skin laxity and facial symmetry, since many people have one side larger than the other. She asks about grinding, clenching, jaw pain and dental history. If bone is the main factor, she will explain that Botox can soften but not reshape the jaw. This honesty helps set realistic expectations and avoids unnecessary treatment. Photos of your jaw from the front and sides are taken to track slimming.
Treatment options at The Heal, ranked by suitability
- Masseter Botox: jaw Botox relaxes and gradually shrinks an enlarged masseter for a slimmer lower face.
- Lower-face fat reduction: Onda can reduce fat along the jaw when fullness is part of the problem.
- Jawline definition: jawline lifting tightens loose skin for a cleaner contour.
- Profile balance: chin filler can lengthen the face and make the jaw look narrower.
Masseter Botox ranks first because it addresses the most common, treatable cause with no downtime. Doses are adjusted to each side if your masseters are uneven, and a follow-up check can fine-tune the result on your next visit.
Home care and daily habits
If you clench or grind, reducing that habit helps both your results and your teeth. Ask your dentist about a night guard if you wake with jaw ache or worn teeth. Limit chewing gum and very tough foods, which build up the masseter. Notice daytime clenching during stress or concentration and relax your jaw with lips together and teeth apart. These habits help maintain slimming between treatments, though they will not reduce an enlarged muscle by themselves. Gentle jaw stretches and warm compresses can ease tension from clenching.
Safety, downtime and when to see a doctor
Masseter Botox is a common, well-studied treatment. You may notice slight chewing fatigue with tough foods for a few weeks, and small bruises are possible. Rarely, an uneven smile can occur if product spreads, which careful placement reduces. Avoid treatment during pregnancy and breastfeeding or with certain neuromuscular conditions. Persistent jaw pain, clicking or locking should be checked by a dentist or doctor. There is no visible downtime, so it fits easily before a flight; reserve your consultation and read when jaw Botox results appear . Results vary between individuals.
The Heal approach
We confirm whether muscle, fat or bone shapes your jaw before treating, so masseter Botox is used where it can genuinely help.
Expert review
Dr. Yang Jeong-hwa
Medical Director · Board-certified dermatologist · Seoul National University College of Medicine
Written for international patients and reviewed for medical accuracy. Individual results vary; your plan is decided in person after a skin assessment. Our review policy
Visit us
The Heal Dermatology Clinic Jamsil
4F, 329 Olympic-ro, Songpa-gu, Seoul, Korea
5 min walk from Jamsil Station (Line 8), Exit 9
Mon & Fri 10:00–20:00
Tue–Thu 10:00–19:30
Sat 09:30–16:00 · Sun & holidays closed
International patients
Visiting Seoul? Get your plan before you fly.
English consultations with a board-certified dermatologist, 5 minutes from Jamsil Station. Treatments are scheduled around your downtime and flights. International patient guide
1
Message us
Concerns, optional photos and travel dates via form or KakaoTalk.
2
Get your plan
Suggested treatments and timing around your flights.
3
Consult & treat
In-person assessment with Dr. Yang in English, then treatment.
Frequently asked
Square Jaw: your questions answered
How long does jaw Botox take to work?
The muscle begins to relax within one to two weeks, and visible slimming usually appears between four and eight weeks as the masseter shrinks. The effect builds with repeated treatments.
How long do jaw Botox results last?
Results commonly last four to six months. With regular treatments, the muscle may stay smaller for longer, allowing sessions to be spaced further apart. Results vary between individuals. Some patients maintain with two treatments a year.
Will jaw Botox affect my chewing?
You may notice your jaw tires more quickly with very chewy foods for a few weeks. Normal eating and speaking are not affected, and the sensation fades as you adapt.
Can Botox help teeth grinding too?
Many patients who clench or grind find their symptoms ease after masseter Botox, as the muscle becomes less forceful. It is often used alongside dental care such as a night guard.
Keep exploring
Related treatments & guides
English consultations in Jamsil, Seoul
A softer, slimmer jawline with no downtime
Send your photos and travel dates. We reply with a personalised plan before you fly.