Botox + Bruxism = No Smile?

Treating the muscles of mastication/chewing could diffuse to lip elevator muscles. The affected muscles will completely come back to normal. Your facial muscular change will be normal in a few to four months with a high probability. Unfortunately treatment of this indication requires significant experience and not all physicians who are very experienced in injecitng Botox for facial lines have the experience in treating your condition, myself included.

Your smile will come back and it is unlikely that the botox to the upper face caused the crooked smile unless the zygomatic muscles were effected by deep injection on the cheek. However, if the masseter was injected that should not cause your smile to effected. Ask your surgeons which muscles were injected for the bruxism.

Thank you for your question Suzanne1980. 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.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!

Usually Botox for bruxism is a safe treatment. The masseter muscle is pretty far away form any smile muscles. 

Botox für Bruxismus (Zähneknirschen) ist im allgemeinen eine Sichere Behandlung, da die Lachmuskeln weit vom Masseter Muskel entfernt sind, welcher für diese Anwendung behandelt wird.

Botox to the lower face likely caused what is going on- the pain likely from the non-injected muscles working against the paralyzed muscles. It is hard to tell what exactly happened, but your injecting physician can let you know what muscles were injected and what to expect. You can expect it to wear off in 3-4months however.

Without seeing a picture, it is hard for me to say absolutely what is accounting for your inability to smile fully.  However, I have seen patients with similar complaints.  It is usually the result of injecting the Botox too low when treating the crow's feet areas.  If the Botox is injected too low, it can affect the muscles that are used to raise the corners of your mouth when you smile.  Given that the effects of Botox are only temporary lasting 3-4 months, your smile should return fully within that timeframe.

I hope my answer was helpful.