Different Skull shape

[Thechickentrainer1999]

Which breeds have a skull that covers their whole brain and which breeds don't have a skull that covers their whole brain?

 

[oldhenlikesdogs]

The only breeds I know that can have incomplete skulls are those that have crests and also have a vaulted skull which some breeders like because it makes the crests look larger. Silkies and polish are the ones I've experienced or read about.