What causes this difference in hollow cheeks?

[WhosJona]

I’ve noticed that some hollow cheeks give the appearance of connection between the zygos, jaw, and chin, while others don’t. What explains this difference?

Connection

Non-connection — Kortajarena‘a line doesn’t taper to the chin.

 

[shessonice]

zygomatic arch

 

[WhosJona]

@Orc