Is it possible to inject botox only the upper part of the masseter without affecting the lower part?

[Curryfinder]

Title. I dont have classic bruxism masseters but think my zygo would looks nice if my upper part of masseters would be a bit smaller but keep as much bigonial width as possible

 

[Seong Gi-Hun]

 

[CalulArgintiu59]

It's like asking can I hypertrophy the lower part without the upper part? Guess what? Not possible you can't target only one part of the masseter