the soyboy grin increases their midface and makes them look even worse

[john_cope]

the soyboy grin, or just an open smile in general, will make you look beta.
if you are going to smile you should not make it a childish, all teeth showing smile, but a wide one with only the upper teeth showing, if at all.
closed smiles or grins are better because they are similar to duckface, which artifically imitates a good filtrum to chin ratio and compact midface

compared to

 

[Ekeoma_The_BBC]

closed smiles are good, they push the fat underneath your cheeks up giving better under eye support momentarily giving you "chico tier" fatpads the moment you smile