Can masseter Botox do permanent damage to the nerves or muscles? (Photos)

I can happily announce that no effect related to Botox injection is permanent. Sometimes mimic muscles can be affected from masetter injections, but just like any other complications of toxin injection, this is completely reversible. There is nothing you can do at the moment, just wait and see. No worries.

Muscle damage and/or nerve irritability are both side effects of any neurotoxin, such as Botox or Xeomin, so yes this could be a possibility. If you are worried I would speak with your injector and have them take a look

Thank you for your question! I can happily announce that no effect related to Botox injection is permanent. Sometimes mimic muscles can be affected from masetter injections, but just like any other complications of toxin injection, this is completely reversible. There is nothing you can do at the moment, just wait and see. Best of luck! 

Hey there
Masseter injections do carry the risk of botox migrating anteriorly, this would affect the risorious muscle which is responsible for the lateral pull of your smile. It's much more likely that the botox has temporarily paralysed this muscle rather than you having any permanent nerve damage. Hopefully it should be wearing off some time soon.

It is possible that the risorius muscle was affected by the injection. If the injection is too anterior, this can happen. It should all get better as Botox wears out. It doesn't cause permanent weakness. Dosing in this area is high, so it might take longer than normal to resolve. 

Thank you for your question and for sharing your photographs silleyldy. I understand your concern. Botox is a purified protein used to address wrinkles associated with facial expression. When injected into the skin Botox will relax the muscles and smoothen out the overlying wrinkles. The most common areas of treatment are in the upper face. These include the horizontal lines seen on the upper forehead when one raises the brows, the vertical lines seen between the brows when one frowns (frown lines), and the crow's feet seen around the eyes when one smiles.It is difficult to make an assessment without knowing the dose used and the exact placement of the product. However, I hope the information provided here is useful.Botox can be placed in the masseter muscle in the lower face to contour the lower face and address pain associated with TMJ. In this area 20-40 units of Botox are used per side. Depending on the reason for the enlargement of the muscle, permanent results may be achieved. For example, some people have a habit of grinding, clenching, or biting their teeth subconsciously. Often times this happens in their sleep when they are not aware of it. Botox placed in this muscle will relax the muscle and the grinding, clenching, and/or biting will decrease. This will reduce the size of the muscle. If the brain gets accustomed to this and the person stops grinding, clenching, or biting, then the muscle will not become enlarged or as enlarged again. However, if the habit starts again, the muscle will likely get larger.
To determine if someone is a good candidate for this treatment it is necessary to look at a person’s lower face when biting and comparing it to when the person is not biting. If a bulge is seen on the outer portion of the jawline, then the person is likely a candidate. It can also be felt with the fingers when biting.
In the mid face, the risorius muscle and zygomaticus muscles sit near the masseter muscle which is treated for TMJ pain or to contour the lower face. When smiling, the risorius muscle pulls the corners of the mouth outward towards the ears and the zygomaticus muscles pull the corners of the mouth upward. The masseter muscle is used to bite down when eating. If Botox spreads from the masseter muscle forward toward the risorius muscle or upward toward the zygomaticus muscles, these muscles can also become relaxed, leading to the appearance of an asymmetric smile. This side effect resolves on its own in 2 weeks to 4 months, depending on the severity. Some find that laser skin tightening treatments using infrared light or radiofrequency may speed up the resolution process.If I had a patient with the concern described here I would say that the risorius muscle has been affected. But I would reassure the patient that the results are not permanent.With any injection, there are risks such as pain, bleeding, bruising, redness, swelling, tenderness, and infection. We take special precautions to minimize these risks such as using a painless technique. We also treat bruises with a laser as early as the next day. Bruises usually resolve within two weeks if untreated. After a laser treatment bruises usually resolve in 1-3 days, but may still take two weeks for full resolution. In addition to these risks, with Botox there is also a risk that the product spreads or diffuses to nearby structures. Spread to nearby muscles can lead to side effects such as the temporary appearance of droopy eyelids or a temporary asymmetric smile.

After a Botox treatment, I recommend that my patients avoid heat exposure, alcohol consumption, and strenuous exercise for 24 hours and not lie down flat for four hours. This is because all of these activities may possibly lead to the movement of the product and consequent side effects such as droopy eyelids. Although there have been no definitive studies shown that these actually occur and some physicians do not provide such aftercare instructions, in the absence of data I err on the side of caution and recommend that my patients avoid such activities.

Please consult with a doctor for specific recommendations. Good luck!

To my knowledge botox has never caused permanent damage but can last 6 months or more so i would suggest you are almost out of the woods . If your smile has been effected it may be that the placement of botox was too high and too far forward causing inadvertent injection into the risorious muscle which pulls the mouth corner to the side .Hang in there I expect a full recovery very soon