I Had Botox in my Masseters 2 Days Ago, when I Can Expect to Notice Any Effect? (photo)

I had botox injected into my masseters for jaw reduction and to stop my clenching and grinding two days ago. I don't see or feel any change yet. Can you tell me when I can expect to notice any changes and what they might be? The doctor said I should probably come back in 9 month's time for more injections but I don't know how much botox he used, he injected at 4 sites on both sides.

Doctor Answers 16

Timeline for masseter injection

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}
The sequence is the following:
1) botox injection 
2) within 2 weeks, you should feel that your muscles can't clench down as hard
3) Over the course of the next many weeks, the masters will slowly shrink and your face will slowly slim. This is due to the muscle atrophying as a result of not working as hard (analogy: if you have your arm in a cast for a few weeks, it will be smaller than the other arm when the cast comes off).

People normally notice reduction in grinding/clenching and less discomfort/tension within the first couple weeks.  The changes in facial shape are more gradual.

Botox and Masseters Muscle

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

Most of my patients begin to see and feel the effects within two weeks. That muscle is extremely strong and so it does require a bit longer than the forehead muscles to fully react. It will get better, but you should start noticing things changing within a few weeks. You will notice a lessening of the tension in that muscle and less of the strain. I usually see people back within 6 months, especially ones I treat for TMJ, because they can start feeling the Botox wearing off about that point and I prefer they don't get back to baseline again, and so do they!

Botox dosage for masseter and timeline

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}
Thank you for your question. Botox in the masseter region usually takes longer than in the standard areas to take effect. I tend to use anywhere from 15 units (conservative treatment) to 50 units (for someone with really strong masseters) on each side to get the desired result. It may start within the first week but I tell my patients to wait three weeks before doing a more thorough evaluation. The treatment typically lasts longer than the forehead/crows feet/frown regions. It is also a gradual onset of the return of masseter function. I have tried the masseter injections myself and space the treatments around 4 months apart, but use smaller doses to maintain the effect. I normally know the effects are wearing down when I start to clench my teeth more heavily at night when asleep. Once you stop using Botox, the masseter muscles will return to their original baseline when the effects of Botox wears off completely.

You might also like...

Botox Results in Masseter

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}
Botox usually takes 2 or 3 days to start to work, and will continue to improve over the first 7 to 10 days. Once the effect starts to wear off, you will need a repeat treatment to maintain results. Some find that the effects last longer after having multiple treatments, even up to a year.

Botox and Dysport for masseter reduction, "V-line"

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

You won't see a change until about 7-10 days.  Depending on the dosage used by your physician, and where in the body of the masseter muscle he injected, the degree of "tapering" and change will vary.  Typically 4-5 injections are performed on each side along the inferior border of the muscle, but taking the injections more superiorly does help to enhance the final result.  The Botox will have worn off in 3-4 months, so 9 months is too long to wait for a repeat injection.  Even with the largest muscles you will see a visible reduction in size with proper technique after one injection, though you may not achieve the maximal reduction possible with Botox until you have had 2-3 sessions.    

Donald B. Yoo, MD
Beverly Hills Facial Plastic Surgeon
4.9 out of 5 stars 60 reviews

Botox for facial contour

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

Assuming this is your first injection of Botox, you should start feeling the effects within 2 weeks. Without knowing how many units were injected to your masseters, it's difficult to say how much of a reduction you'll see over the course of the next few months. I would check in with your provider when you start to feel like you can clench and grind again, (the Botox is wearing off), then determine how much contouring was achieved and formulate a long-term maintenance plan.

Botox Results in Masseter

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

Usually two weeks after Botox injections patients begin to see and feel a difference from the injection. Because the muscle is so strong, it requires a bit longer than the forehead muscles to fully react. You will notice a lessening in the strength and degree of the muscle over the next few weeks. Visual reduction may take a few months and we usually retreat at 3-4 months and then wait another 6 months for full visual shrinking of the musculature.


My best, 

Dr. Anil Rajani

Masseter muscle Botox

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

The masseter muscle is one of the muscles activated during chewing. It’s located at the “angle of the mandible”, or “angle of the jaw”. Masseter muscle hypertrophy is enlargement of the masseter muscle, and can contribute to a harsh, square look at the angle of the jaw. Botox can be used to relax this muscle, and to soften the look of the lower face. I usually start with 50 units of botox (25 units on each side). When Botox is used to relax the facial muscles that cause fine line, the maximum effect is seen in 7-10 days. When Botox is used to reduce masseter muscle hypertrophy, the maximum effect is not seen for 3 months. Results can last up to 9 months. I recommend repeat injection every 6 months if you would like to maintain your results. 

Botox and Masseter muscle

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

It generally takes 2 weeks or more for the muscle to shrink. Over time you may need additional Botox in this area to shrink the muscle. Botox lasts 4 to 6 months in this area and with repeated injections you will continue to have improved results. Best, Dr. Green

Muscle thinning in the masseters for teeth clenching may take a while after Botox treatment

{{ voteCount >= 0 ? '+' + (voteCount + 1) : (voteCount + 1) }}

Usually Botox injected in the masseter muscles can minimize teeth clenching, not grinding. After the clenching diminishes, the muscle starts to become less hypertrophied, or bulky. Just like a weight lifter who stops working out; the muscles are still going to be bulky for a while. There is a gradual diminishing of girth.

Ronald Shelton, MD
Manhattan Dermatologic Surgeon
4.9 out of 5 stars 38 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.