Square Jaw Botox (Masseter Botox) in Korea — The Complete Guide

Who it suits / who it doesn't

Square jaw Botox is an injection of botulinum toxin into the chewing muscles at the sides of the jaw (the masseters) to reduce muscle volume and slim the lower face. It takes about 10 minutes with no incision or anesthesia, so it is easy to fit into a short trip. The toxin temporarily blocks the signals that make the muscle contract, so the resting muscle shrinks over several weeks. Unlike wrinkle Botox, which changes in a few days, it takes time to show.

• You clench your back teeth and a firm bulge rises at the side of your jaw below the ears
• Your lower face looks wide and angular in front-facing photos
• You often clench your teeth or chew tough food or gum
• You'd like to refine your lower-face line without surgery first
• You've been told you grind your teeth in your sleep, or your jaw feels tight in the morning (whether to treat this is up to the doctor)

Muscle-Type vs. Bone-Type Jaw — Self-Check

A wide lower face usually comes down to muscle, bone, or fat and sagging. The right approach depends on the cause.

3-step mirror self-check

1. Face the mirror and place your fingertips just in front of the corner of the jaw, below your ear.
2. Clench your back teeth for 3 seconds and release, a few times in a row.
3. If a firm, large bulge rises under your fingertips when you clench, muscle is likely a big part of it. If there is little change but the angle is still clearly defined, bone may be the bigger factor.

When Results Appear

• Same day
  No visible change. Needle marks and small bumps usually settle within an hour.
• 1–2 weeks
  You may start to feel slightly less force when chewing hard food. Some people feel they clench less.
• 2–4 weeks
  The muscle starts to shrink and the side of the jaw looks gradually softer. At this stage the change is easier to see by comparing photos than in the mirror.
• 6–8 weeks
  This is when the reduction in muscle volume is clearest. Compare with your before photo taken from the same angle.
• 3–6 months
  The muscle is gradually used again and begins to return to its original volume. This is your guide for timing the next treatment.

Because the change comes on slowly over several weeks, it is easy to feel it "isn't working." It's best to wait at least 6 weeks before judging.

How Long It Lasts, Repeat Treatments, Dose & Spacing

How long a single treatment lasts varies a lot, but it is usually around 4–6 months. People who clench strongly or have larger muscles tend to see it return sooner.

• Repeat effect: Repeating 2–3 times while the effect is still present keeps the muscle smaller for longer, and the interval between treatments often grows.
• Dose: The doctor decides based on muscle thickness and any left-right difference. Unit values differ between products, so numbers from another clinic or another product can't be compared directly.
• Spacing: To avoid re-injecting while the effect remains, an interval of at least 3–4 months is standard.
• Tolerance: It is known that, though rare, repeating at short intervals or often using large amounts can make the effect weaker. If this worries you, you can ask about a purified toxin.

Teeth Grinding, Clenching & the Jaw Joint

Clenching or grinding can be one reason the masseter becomes enlarged. Some people feel less morning jaw tightness after square jaw Botox as the muscle's force decreases, and related studies have been reported.

However, if you have teeth grinding, jaw joint pain, clicking or difficulty opening your mouth, there are many possible causes, so an examination by a dentist or the relevant specialty comes first, separate from any cosmetic goal. The doctor decides whether Botox is appropriate as treatment or whether another approach such as a mouthguard suits you better.

Combining with Salivary Gland and Trapezius Botox

People who want to refine both the lower face and the neckline often ask about other areas on the same day.

• Salivary gland (parotid / submandibular) Botox: considered when a bulge below the jaw corner or jawline is caused by the salivary glands. An examination is needed to tell muscle from gland.
• Trapezius Botox: if the muscles on top of the shoulders stand out and make the neck look short, treating them too helps balance the face and neckline.
• Chin Botox / filler: also treating a dimpled or short chin makes a slimmer look more natural.

How to Confirm Genuine Product and Dose (Essential)

The results of square jaw Botox appear over 6–8 weeks, so you can't tell on the day whether it worked. That makes checking on the day of treatment especially important.

1. Before treatment, confirm the product name and the dose (units) for each side.
2. Ask to see a new vial opened in front of you, and ask to see the product name, dose and expiry date on the box and the vial label.
3. If you'd like to watch the dilution or the filling of the syringe, tell them beforehand.
4. After treatment, ask to see the empty vial or label and take a photo.
5. Check that the receipt and itemized statement list the product name.

Treatment Day Flow & Your Travel Schedule

1. 1
   Consultation (15–20 minutes)the doctor checks muscle size and any left-right difference as you clench and release, then decides the product and dose.
2. 2
   Genuine check and photosconfirm the opening of the vial and take front and side photos.
3. 3
   Injection (5–10 minutes)injected at several points on the side of the jaw. Most people have it without anesthesia, and the sting is brief.
4. 4
   Afterwardyou can eat and go sightseeing right away.

• A same-day treatment is enough. Having it the morning after you arrive leaves your schedule relaxed.
• There are mostly no flight restrictions, but leaving about a day of margin if possible gives peace of mind.
• You'll see the results after you return home. If you send photos from the same angle as before at weeks 4 and 8, the clinic will review them.

Aftercare

• Don't lie down or lie face-down for 4 hours after treatment.
• On the day, don't press or rub the jaw area, and avoid meridian massage, gua sha and jaw massage for about 2 weeks.
• Avoid saunas, jjimjilbang (Korean spas) and hot baths for about 1 week. Move any jjimjilbang plans to before your treatment.
• Avoid alcohol for at least 1–2 days and strenuous exercise on the day.
• For the first 1–2 weeks, it helps to cut back on foods that need long chewing, such as tough meat, squid and gum.
• Washing your face and applying makeup are usually fine from that evening.

Side Effects and When to Contact Us

• Common: redness and small bumps at the injection sites (a few hours), bruising (1–2 weeks), and a feeling of weakness or quick tiredness when chewing hard food (several weeks; most people adapt)
• Occasional: left-right differences, or part of the side of the jaw bulging when you smile or tense it (needs checking after 2 weeks)
• Rare: an awkward corner of the mouth when smiling, or the area below the cheek looking hollow or the skin looking loose as the muscle shrinks. These mostly recover as the effect fades.

Square Jaw Botox vs. Facial Contouring Surgery

If the bone is wide, repeating Botox alone may not change things as much as you hope, and some people with muscle-type jaws wonder about surgery. A common approach in consultations is to reduce the muscle first with Botox, then judge whether surgery is needed based on the bone contour that remains.

Questions to Ask at Your Consultation · How to Choose a Clinic

Good questions to ask at the consultation

1. Is my lower face muscle type or bone type?
2. Which product will you use, and how many units on each side?
3. Can I check the opening and label, and see the empty vial afterward?
4. Will the doctor perform the injection personally?
5. When and how will the results be checked, and what happens if a left-right difference remains?
6. Should the salivary glands and trapezius be looked at too?

When choosing a clinic, check whether the doctor personally examines you and explains muscle, bone and salivary glands, whether they are open about the product and dose, and whether they offer foreign-language communication and a system for reviewing photos after you return home. KBEAU takes care of consultations and interpreting at partner clinics in Gangnam and Apgujeong, as well as post-treatment photo reviews.