Jawline Slimming / Botulinum Toxin


Botulinum toxin injection into Masseter muscles

Injecting botulinum toxin reduces the jaw muscles, resulting in a slimmer facial contour and a smaller face effect. Additionally, if you have a habit of clenching your teeth, weakening your masseter muscles can reduce the burden on your back teeth.

Recommended for:

  • Individuals with well-developed masseter muscles leading to a perceived larger face.
  • Those with a strong habit of teeth clenching or grinding, resulting in significant wear on the molars.
  • For individuals in their 40s and beyond, it is not recommended to undergo Botulinum toxin injections in the masseter muscles. This is because the reduction in masseter muscle volume can lead to sagging of the skin, which is more likely to occur in this age group.

Flow of treatment

The actual treatment process is as follows. For more information on the formulation and needles used, see the Botulinum toxin treatment page.

Examination / injections / records

We’ll have you clench your teeth so we can assess the development and extent of the masseter muscles as well as any asymmetry between the left and right sides.

Since the masseter muscles around the jawline are large, a minimum of 50 units (25 units per side) will be administered. For individuals with strong teeth grinding habits and well-developed masseter muscles, we recommend 80 units (40 units per side).

If there is asymmetry in the tension of the jaw muscles on either side, I will adjust the dosage accordingly. All information regarding injection sites, depth, and units will be recorded along with photos in your medical record, ensuring a safe and consistent treatment for subsequent sessions.

Within 1 month

After 1 to 2 weeks, you may experience symptoms such as jaw fatigue when chewing. Symptoms are mild and improve within a few days. After a month, you can feel that the masseter muscle has atrophied and become smaller.

Coretox injections into the masseter muscle are not eligible for free touch-ups, but if there is an extreme difference between the left and right sides, or if only a part of it protrudes, we will correct it. Please make an appointment and consult your doctor within 3 weeks after treatment.

3-4 months later

One injection may not be effective enough. Usually, a total of 2 to 3 injections are given every 3 months. After that, if you notice tension in the masseter muscle, you will receive an injection to maintain it.

Case photos of jaw slimming treatment with botulinum toxin injection

Jawline before treatment
Jawline one month after treatment

The photos above were taken with her jaw relaxed.

In the first picture, the masseter muscle is enlarged and protrudes. Because she had a habit of clenching her teeth and her masseter muscles were extensively enlarged, she received an injection of 80 units of botulinum toxin (Coretox). Since the right masseter muscle was more developed, the injection amount was increased to the right side.

The second photo is one month later. Her masseter muscle will start to shrink in about a month after the Coretox injection. Her jawline will become slimmer and her face will look smaller.

Botulinum toxin injections into the masseter muscle can be expected to relieve the symptoms of people who grind their teeth or clench their teeth, and can also be expected to improve jaw pain caused by temporomandibular joint disorders and tension-type headaches.2

Side effects and precautions

For information on side effects and post-treatment precautions, see Potential side effects of botulinum toxin injections.

Price for Jawline treatment with botulinum toxin injection

At our clinic, we use “Coretox” as a botulinum toxin preparation.

ItemFee (tax included)
First visit ¥3,850
Revisit ¥1,650
Jawline 50 Units¥29,700
Jawline 80 Units¥39,600
  1. Each injection requires a consultation every time. Please be aware that a separate consultation fee will apply.
  2. Coretox injections into the masseter muscle are not eligible for free touch-ups, but if there is an extreme difference between the left and right sides, or if only a part of it protrudes, we will correct it. Please make an appointment and consult your doctor within 3 weeks after treatment.

Frequently Asked Questions About Botulinum Toxin Injections for Jawline

For general inquiries about Botulinum Toxin injections and post-injection questions, please refer to the “Frequently Asked Questions about Botulinum Toxin Injections.”

How long is the downtime?

Please refer to “Questions after injection“.

Is the treatment painful?

At our clinic, we use very thin needles, so there is almost no pain.

For Jawline Botulinum Toxin injections, how many units do you recommend?

Due to the relatively large size of the masseter muscles, we recommend a minimum of 50 units (25 units per side). For individuals with a strong teeth-grinding habit and significant hypertrophy of the masseter muscles, we suggest 80 units (40 units per side).

How long does it take to see results after the injection?

Typically, you can start to feel the effects as the masseter muscle atrophies about a month after the injection. Some individuals may not experience significant effects after just one treatment session. With repeated injections, the masseter muscle gradually becomes smaller, leading to more noticeable results.

How many injections are needed?

For individuals with well-developed masseter muscles, it is recommended to undergo injections approximately three times, spaced three months apart. Afterward, injections can be administered as needed, when you notice a return in muscle strength and prominence.

If the results are unsatisfactory, can I receive additional injections for free?

No, we do not offer complimentary touch-up injections for Jawline Botulinum Toxin treatments.

However, if there are extreme asymmetries or specific concerns, such as protrusion on one side, we will address them. Please schedule a follow-up appointment within three weeks of the treatment for a consultation with the doctor. Please note that there will be an additional consultation fee.

How long does the effect last?

After multiple injections of Botulinum Toxin leading to atrophy of the masseter muscles, it may take over a year for them to return to their original state. By consciously working on improving teeth grinding habits, you can further extend the duration of the effect.

List of references/websites
  1. Fedorowicz Z, van Zuuren EJ, Schoones J. Botulinum toxin for masseter hypertrophy. Cochrane Database Syst Rev. 2013 Sep 9;2013(9):CD007510. doi: 10.1002/14651858.CD007510.pub3. PMID: 24018587; PMCID: PMC7207780.
  2. Pihut M, Ferendiuk E, Szewczyk M, Kasprzyk K, Wieckiewicz M. The efficiency of botulinum toxin type A for the treatment of masseter muscle pain in patients with temporomandibular joint dysfunction and tension-type headache. J Headache Pain. 2016;17:29. doi: 10.1186/s10194-016-0621-1. Epub 2016 Mar 24. PMID: 27011213; PMCID: PMC4807183.
  3. Almukhtar RM, Fabi SG. The Masseter Muscle and Its Role in Facial Contouring, Aging, and Quality of Life: A Literature Review. Plast Reconstr Surg. 2019 Jan;143(1):39e-48e. doi: 10.1097/PRS.0000000000005083. PMID: 30303926.
  4. Kundu N, Kothari R, Shah N, Sandhu S, Tripathy DM, Galadari H, Gold MH, Goldman MP, Kassir M, Schepler H, Grabbe S, Goldust M. Efficacy of botulinum toxin in masseter muscle hypertrophy for lower face contouring. J Cosmet Dermatol. 2022 May;21(5):1849-1856. doi: 10.1111/jocd.14858. Epub 2022 Feb 28. PMID: 35176198.
  5. Yeh YT, Peng JH, Peng HP. Literature review of the adverse events associated with botulinum toxin injection for the masseter muscle hypertrophy. J Cosmet Dermatol. 2018 Oct;17(5):675-687. doi: 10.1111/jocd.12721. Epub 2018 Aug 9. PMID: 30091170.

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