How should I schedule Botox treatments?

Hello, I am a male office worker.

I have a somewhat square jaw. I've been looking into it and am planning to get Botox. How is the typical schedule for touch-ups or the treatment cycle set?

Perhaps because I enjoy chewy foods and have a habit of grinding my teeth while sleeping, the muscles under both of my square jaws have become extremely hard and hypertrophied. I was concerned that my face looked a bit angular and my impression seemed strong, so I heard from others that a single Botox injection can significantly reduce the muscle size, and I plan to give it a try.

I am curious how many units of Botox are typically needed for a man with a square jaw to see muscle reduction results during his first treatment. Also, I would appreciate any tips on how often I should schedule follow-up treatments to maintain the slimmed-down line after the initial session.