Can a masseter muscle grow into two bumps in just 4 weeks? (Photos)

My dermatologist recommended Botox i masseter muscles. Mysteriously two bumps appeared approximately 3-4 weeks post Ultherapy. I went back to my dermatologist and she is telling me that I’m grinding my teeth and I need Botox in the masseter muscle. Isn’t the masseter muscle just like any other muscle? Is it possible for it to grow so quickly? Thank you for your time. My doctor also said that it is not a hematoma