Why Can't I Open my Mouth After Having Botox?

If it is due to the Botox, then the Botox was either injected into the wrong muscles or diffused into unintended muscles. This can occur if the injections for crow's feet are made too deep or too medial. This leads to the muscles that help elevate your lips and move your nose. If it is due to the Botox then, the effect will wear off, but it will take 3 to 6 months. You should be closely followed by your doctor to make sure there is not anything more serious occurring.

Dear Sommer
If your doctor's treatment pattern included the lower eyelid and this was done too deeply, it is possible for the BOTOX to affect the muscles of the face that control the smile. These muscles include the zygomaticus major, minor, and the lip elevators. The swollen nose effect occurs when the levator labii alaeque nasi muscle which lies along the side of the nose and serves as a minor lip elevator gets too much treatment. This muscle is sometimes intentionally injected to treat the so-called gummy smile.
When BOTOX helps our appearance, feedback from the treated muscles favorably affects brain chemistry. Functional MRI studies of the brain have shown that BOTOX used to reduce the pinch at the eyebrow has a favorable effect on mood centers in the brain. Anecdotally, I have seen patients who received unintentional treatment to the muscles that are responsible for mouth movement and smile. The problem is not just that the smile is asymmetric or weak but these treatments also have a profound adverse effect on mood. The effect on appearance may or may not be dramatic but the effect on mood can be disabling and lead to depression. So don't let anyone minimize the significance of this complication.
Now the good news. The BOTOX effect will wear off but it can take months. Your doctor may be very open about the problem in which case he or she can follow you closely or they can be very defensive about the result in which case you may need to find a new doctor. If you become depressed or feel withdrawn recognize that this is the central (i.e. brain) effect of your BOTOX treatment causing action on the wrong muscle groups. This will wear off eventually but it is possible to be so dysphoric that it affects your ability to function socially. If this is the case, it is worthwhile to seek the support of a psychotherapist to help work with you until these symptoms resolve.

Sommers
I don't think that the Botox is affecting your mouth - unless it was injected into your cheek muscles which help elevate the lips. If you had significant swelling after your photofacial treatment, this is probably why you have difficulty opening your mouth. I sometimes give a 6 day course of methylprednisolone to patients that have significant swelling after photofacial treatments.

A photofacial willnot do this. Botox injected close to the msucles that allow you to smile can affect your smile ability.  Unfortunately, it wil take 3-4 months to wear off.

I would recommend that you follow up with a physician who is experienced with Botox. If no improvement is seen or worsening of your condition occurs, then I would report to an emergency room for immediate evaluation and treatment. There is definitely something odd going on that does not make any sense. I wish you the very best and I hope you find this helpful!