Korea masseter Botox is an injection of botulinum toxin type A into the chewing muscle at the angle of the jaw, and in Gangnam it normally starts with an assessment of whether that muscle is really what makes the lower face look wide. The doctor asks you to clench, feels the muscle bulge, compares both sides and checks for habits such as grinding. Only then are injection points marked and the units per side chosen. The injections take a few minutes after ice or numbing cream, and most people return to normal plans the same day. The muscle thins gradually over several weeks, so the outcome is judged at a follow-up rather than in the mirror that evening.
Guide
What the doctor checks before marking the jaw
A wide lower face has several possible causes, and toxin only changes one of them. When you bite down, an enlarged masseter hardens and pushes outward just in front of the ear lobe line. If the width stays the same while clenching, the shape may come from the jawbone itself, from fat, or from the parotid salivary gland, and the injections will do little.
Many Gangnam clinics photograph the face from the front and at an angle, and some use ultrasound to see muscle thickness. The consultation should also cover dental habits, earlier toxin sessions and conditions affecting muscles or nerves.
- Clench test: does the corner of the jaw bulge and harden?
- Side comparison: is one masseter larger than the other?
- Habits: night grinding, daytime clenching, gum chewing
Guide
When one side of the jaw is larger than the other
Uneven masseters are common and often linked to chewing on one side or clenching under stress. Toxin can be dosed separately for each side, which is one reason a written plan should give units per side rather than one total.
Published cases support this approach. In a 2021 report in BMJ Case Reports, Nilesh and colleagues described a patient with one enlarged masseter of unknown cause, treated with botulinum toxin type A, whose muscle volume reduced and facial symmetry improved. A single case cannot predict your outcome, but it shows why both sides are measured instead of treated identically.
If the larger side relates to a bite problem or a missing tooth, a dentist should check it, because the muscle may enlarge again.
Guide
Slimming the face versus easing clenching
The same injection is requested for two different goals, and the plan differs slightly between them. Stating your goal at the start helps the doctor choose the dose, points and follow-up.
| Aspect | Slimmer lower face | Clenching or grinding relief |
|---|---|---|
| Main aim | Narrower jaw outline | Less muscle force and tension |
| What is assessed | Muscle bulge and face shape | Tooth wear, jaw pain, sleep habits |
| How change is judged | Photos at a follow-up | Symptoms over the following weeks |
| Points to discuss | Cheek hollowing, smile change | Chewing fatigue, jaw joint symptoms |
Guide
Jawbone findings and what they mean for repeat sessions
A muscle that works less puts less load on the bone it pulls on, so researchers have asked whether repeated injections thin the jaw. In a systematic review and meta-analysis published in the Journal of Oral Rehabilitation, Moussa and colleagues analyzed human and animal studies and found about a 6 percent decrease in the thickness of the outer cortical bone of the jaw in humans after toxin injection, with no evident change in overall bone volume or density.
The clinical meaning is still being studied, but it supports a measured plan: leave enough time between sessions, use the lowest dose that reaches your goal, and avoid stacking extra top-ups. Tell your dentist or orthodontist about the injections, especially before implant or jaw treatment.
Guide
Timing a Gangnam visit around a slow result
The injection day itself is short, and same-day flights are generally possible. The visible narrowing, however, builds over the following weeks, so the person who treats you cannot judge the outcome before you leave. If you can, book the session early in a longer stay, or arrange to send photos after a month.
Avoid pressing or massaging the jaw corners and skip saunas and intense exercise for the rest of the day. Mild tenderness on hard food can last a few days.
Evidence
Research behind this page
- Adverse effect of botulinum toxin‐A injections on mandibular bone: A systematic review and meta‐analysisJournal of Oral Rehabilitation · 2023 · doi:10.1111/joor.13590
Systematic review and meta-analysis of human and animal studies reporting about a 6 percent reduction in mandibular cortical thickness in humans after toxin injection, with no evident change in bone volume or density.
- Management of unilateral idiopathic masseter muscle hypertrophy with botulinum toxin type ABMJ Case Reports · 2021 · doi:10.1136/bcr-2020-239056
Case report of one-sided masseter enlargement of unknown cause treated with botulinum toxin type A, with reduced muscle volume and improved facial appearance.
FAQ
Questions about Botox in Gangnam
Can jaw toxin be combined with filler or lifting on the same trip?
Yes, combining is common, but the order and spacing should be planned by the treating doctor. Toxin narrows the lower face slowly, while filler changes shape at once, so some doctors prefer to see the slimming first before adding chin or jawline volume. Energy-based lifting on the same area is often scheduled before the injection or on another day. Bring a list of everything you plan for the visit.
What if chewing feels weak after the injections?
A tired feeling when chewing tough food is a known, usually temporary effect in the first weeks. It happens because the main chewing muscle is producing less force, and the other muscles take over as you adapt. Choosing softer meals for a while helps. If chewing becomes difficult, or weakness spreads to the smile or speech, contact the clinic that treated you without delay.
Can masseter injections help a clicking or painful jaw joint?
They are sometimes used for jaw muscle pain, but that is an off-label use and a clicking joint needs its own diagnosis. The Moussa review notes that toxin is increasingly used in dental practice for overactive chewing muscles linked to jaw disorders. A dentist or jaw specialist should examine the joint first. Toxin relaxes muscle; it does not repair a displaced joint disc.
Should I tell my dentist about the injections?
Yes, a dentist or orthodontist should know, because toxin changes muscle force on the jaw and may affect bone thickness over time. This matters most before implants, orthodontic work, jaw surgery or a new night guard. Keep a record of the dates, the product brand and the units per side. That record also helps a future doctor plan safely. Bring it to every future consultation, in Korea or at home.
Who should avoid masseter toxin?
It is not appropriate during pregnancy or breastfeeding, with an infection on the jaw skin, or with a neuromuscular condition such as myasthenia gravis. People whose lower-face width comes from bone or the salivary gland will see little change. Those taking certain antibiotics, or with a past allergic reaction to a toxin product, should raise it first. The assessment should end with a clear yes or no.
How can I check the result after flying home?
Take front and angled photos before the session in the same light, then repeat them at about four and eight weeks. The masseter thins slowly, so day-to-day mirror checks are misleading. Clench in the photos too, because a smaller bulge is often the first visible sign. Many clinics review photos sent after the visit and advise whether a second session makes sense.