Is there a way to have botox in the side of the nose for each nostril to stop them moving when I smile?

It’s possible for Botox to help a bit with this, but a careful examination must be done to determine where to inject.
Good luck. Dr. Aldo

Yes, a few units of Botox can be injected on each side of the nose. The key is to place it in the precise location of the muscle

Yes, there are a few ways that botox can be injected to help with sides of nostrils elevating and tip of nose droop during smiling.  It would be best to have any examination done but results can be quite pleasant with a relatively small amount of botox. 
Good luck and stay beautiful!
Dr. Kim

There are a few things that can be done to prevent your nostrils from moving apart too far. In order to determine the cause, you need to be evaluated in person by a plastic surgeon like myself. Good luck from New York City

It is possible to have Botox injections to stop the movement of the nostrils. see a board certifed dermatologist who is experienced in the use of the material