What causes this look? Teeth being visible at all times?

[chickencalves]

I find it difficult to even expose all my teeth while grinning, even with a wide mouth. What's up with these niggas? Also, I've noticed this most on somalis.

 

[Aryan Incel]

Being black

 

[chickencalves]

Being black

Other Africans don't look like that. It's rare on Brazilians and black Americans too