Masseter Muscles & Teeth Grinding
The masseter muscle is the main muscle for chewing. It sits at the angle of the jaw – clench your teeth and feel along the jawbone and you will feel it there like a walnut.
Treating this muscle with muscle relaxant – the same that is used “for anti-wrinkle injections” relaxes and “atrophies” (or shrinks) this muscle.
This treatment can be performed for both aesthetic reasons and medical reasons.
MEDICAL REASONS FOR TREATING MASSETER MUSCLES
Teeth grinding is a common problem. It often causes aching, tension and headaches, especially on waking in the morning.
It is also a cause of TMJ joint (jaw joint) issues, and can prematurely wear the teeth and cause teeth to crack and damage.
Apart from that partners often complain about the terrible grinding noise that happens at night while the offender is asleep!
Small injections into the muscle reduce its strength and are usually effective at reducing or stopping teeth grinding.
The effect lasts for usually 4-6 months, but over time the muscle reduces in size further especially if the treatment is repeated.
AESTHETIC REASONS FOR TREATING THE MASSETER MUSCLE
Some people naturally have a large or prominent masseter muscle. This can be a racial variation and is more common in some Eastern European or Asian countries.
Some people develop an enlarged muscle because of jaw clenching, teeth grinding, or over use of chewing gum. Because the masseter muscle sits at the angle of the jaw, if it is enlarged it tends to cause a square, somewhat masculine face shape.
Generally a more refined, oval or heart shaped face shape, is considered more attractive and feminine.
Using muscle relaxant – as used for anti-wrinkle injections – makes this muscle less prominent and gives a narrower more defined jaw line.
COMBINING TREATING THE MASSETER MSUCLE WITH OTHER TREATMENTS
When we assess a face we treat it holistically. As a general rule we are primarily trying to preserve and restore the volume and gentle curves and shape of youth.
A youthful face has more volume in the top half than the bottom. Reducing the size of the masseter muscle helps to restore this balance, but re-volumising the upper face (cheeks, temples etc) also works in this way.
So masseter treatment is often combined with dermal filler rejuvenation.
The jawline is also weakened by excess fatty tissue.
This can cause jowls, a fullness under the chin, and a loss of definition over the line of the jaw. Both men and women tend to look better with a defined, strong jaw.
Fat removal injections in these areas can make a big difference (see Double Chin treatments here) and often work well in combination with masseter muscle treatment.


“Before and after pictures – Envisage Clinic patients, all after a single treatment. Individual results may vary”
WHAT ARE THE SIDE EFFECTS OF TREATING THE MASSETER MUSCLE
If too much relaxant is used it is possible to weaken the masseter muscle too much. This could conceivably cause difficulty with chewing certain foods such as steak.
However we do not treat the whole muscle and I have never had a patient tell me that this was a problem.
If the injection is misplaced it can affect the smile muscles, causing a weak or asymmetrical smile.
It is important that the injections are placed carefully into the right muscle.
I have never seen this occur in our patients.
HOW LONG DO TREATMENTS LAST?
Generally the effects on muscle strength last 4-6 months.
The muscle will take longer than this to regain its full size.
Repeating the treatment at about 4 months will usually lead to a further reduction in size.
HOW MUCH DO MASSETER INJECTIONS COST?
This depends on how many units of muscle relaxant are used. Generally costs are between $200-$450.
![]() |
Dr Christopher Leat – Medical Director Envisage Skin Clinic Founder and Director. Dr Christopher Leat has 33 years’ experience in Medicine and is a member of The Royal College of Physicians of London. Dr Leat has devoted the last 18 years to Cosmetic Medicine and is recognised throughout Australia as one of the most experienced doctors in the field of Cosmetic Medicine. |

