Botox to lift the corner of the mouth?

The safest place for Botox to lift the corner of the mouth is at the origin of the DAO. In other words, at the jawline as far away from the lips as possible. Be sure to tell your injector about past experiences. Start with a low dose! You may have to come back to get a little more in 2 to 3 weeks, but in your case it’s better to go slow than to have a disappointment. Best wishes. Dr. Aldo

Often the botox doesnt help the mouth corners, sometimes this needs fillers, threads or ultherapy.  I suggest a formal consult.  Best, Dr. Emer.

You can have a small amount of Botox injected into the DAO muscles to slightly elevate the corners of the mouth. Only 5 units or so are needed. Find a Board Certified and experienced injector to work with in your area. 

Botox of about 4-5 units into each DAO muscle should slightly elevate the corners of your mouth. If the injector is unskilled, they may inadvertently inject the lower lip depressors resulting in a poor outcome. Additionally, you may need fillers for the marionette lines and pre-jowl sulcus for a good outcome.  See a skilled injector

Patients like yourself should really be seen by plastic surgeons only. Only plastic surgeons knowledge of anatomy can help you get a good result using Botox and lifting corners of the mouth. Good luck from New York City

You might be best off lifting the angles of your mouth with a combination of Botox injected along the jawline  where are the depressor anguli Oris  is  and a filler in addition .  If you clench your teeth very tightly  and turn your lips down  you may be able to feel this small muscle at your jawline .

Using just 1-2 units on the top corner of each side of mouth is all you need.
More is not better, and can risk your past. 
Dr Kristine Brecht 
Seattle, Wa