That's good to know about the ITB.

On the first point, we are talking past each other. You are talking about muscle hypertrophy, which is the growth of the cells itself. That is accomplished through resistance training. Hyperplasia otoh occurs during distraction histeogenesis due to the muscle being stretched apart which triggers cell multiplication.

Also the study I posted is of an oral and maxillofacial surgery procedure (jaw elongation I believe) where there isn't really a resistance training regimen.