Masseter Muscle Injection 2018-02-08T04:46:22+00:00

What is Masseter Muscle Injection?

Masseter muscle is a thick and rectangular muscle of mastication found in the jawline. Patients with square lower jawline have a masseteric muscle hypertrophy or enlargement of one or both masseter muscles. This is very common with Asians, particularly Koreans, Chinese and other Southeast Asians.

Aside from genetics, enlargement of the masseter muscle is caused by asymmetric chewing caused by dental problems, temporomandibular joint dysfunction, food intakes and personal habits (ie. frequent gum chewing, jaw clenching or grinding and bruxism.

The masseter muscle injection reshapes your lower jaw to reduce the width and shape of your lower face.

Before & After


The masseter muscle is the main muscle of biting and grinding. It is a strong muscle in comparison to the frown muscles or forehead. We usually perform 3 to 5 small injections of anti-wrinkle product into the masseter muscle, as shown below. The amount of wrinkle relaxer used does vary but in general much larger amounts are needed when compared with treatment of wrinkles. Preventing the muscle from contracting over a period of time weakens the muscle and reduces its size.Often a repeat treatment will need to be performed 4-8 weeks later to ensure the best results with followup in 6 months. Over time as the muscle atrophies less muscle relaxant is needed with longer periods between treatments. The results improve significantly over the first year of treatment. The procedure is highly effective, with minimal or no pain and absolutely no downtime at all.

Jaw Line Reshaping with Muscle Relaxing Injections are safe when administered by a medical professional. There have been no permanent side effects reported. Most patients will have regular treatments for many years without ever encountering an issue. After treatment, minor swelling may occur but this is easily covered with make-up if required. Small marks, like mosquito bites, may also appear following treatment but this will only last for a few minutes. If the injection is put in too high it can affect your smile for 2 to 3 month.

There is not typically any swelling, unless a bruise forms. If a bruise forms, this may take a few days to go away.

The injections are the least painful injections of all the treatments that we perform at the clinic. It feels like a small sting when you have an injection.
Facial slimming injections take about 2 to 4 weeks to work as it takes time for the muscle to relax and reduce in size. The maximal effect will be about 8 weeks after the treatment.
We often say to patients that, before treatment when you clench your teeth, the bite muscle feels firm. Approximately 2-3 weeks after treatment the bite muscle will feel soft, a bit like a kitchen sponge. This is the point at which the muscle has been relaxed and you know that it is working.
With the correct amount of units the treatment should last up to 6 months. When you can feel the bite muscle contracting well again we recommend coming back to have a repeat treatment.
Yes, Muscle Relaxant Injections have been shown to reduce teeth grinding activity where other techniques have failed. Teeth grinding can lead to headaches, facial pain and enlarged masseter muscles. A small amount of Muscle Relaxant Injections is all that is required to reduce activity.





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