The corner of my mouth is no longer raising when I smile. What went wrong with my Masseter Botox?

The masseter likely wasn't injected properly and the points were too medial and superior.  With that said, any issues will return to normal in 2-3 months.  Nothing will be permanent.  I wish you the best of luck, Dr. Emer. 

Thank you for the question. You hit the nail on the head: the zygomaticus muscles were affected by the Botox injections. This will resolve slowly over about 3 months. When injecting the masseter for jaw slimming, it is important to place the injections laterally and inferiorly (near the angle of the jaw).  In addition, the injections are placed deeper than typical Botox injections. Please follow up with your provider to discuss your concerns.

Thank you for your question MortgageGirl. 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 in the absence of consistent photographs before and after in the same lighting and angles for comparison. 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 recommend being patient as the side effect will go away on its own without the need for training any muscles.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!

Botox does a good job in facial slimming (masseter injections)  but it sounds like the zygomatic muscle was affected in the process.  Unfortunately there is nothing you can do about this problem now but it will go away in approximately three months.  

Yes, that was the answer I was going to say. MOre than likely it impacted your zygomaticus muscle and it should come back to normal when the Botox wears off.

Since Botox is temporary, no permanent damage was done to your smile muscles. Over the next few weeks to months, you will notice strength returning to your smile spontaneously. This means no muscle retraining will be required...only time.

won't last too long...most likely the injection targeted the wrong muscle...either the injection was too far superior or too close to the nose side of the cheek...not sure I accept the migration story...and it should take some time for the muscle to lose function...should not be right after the treatment...and then the muscle should work again within as little as 3-4 weeks to as long as 2-3 months...don't know what the squirting sensation was...no matter where the botox was injected you shouldn't feel anything squirting unless some dripped onto the surface of the skin which means even less made it to the muscle...

There are a couple muscles which could cause this problem, the zygomaticus or the risorius muscle.  If injected too high, the zygomaticus will be affected, to anterior, the risorius will be affected.  Either way, time will heal the problem and you have no worries about it being permanent.  Steve Weiner, Facial Plastic Surgeon.