Which general advice is recommended for victims of mouth breathing?

[SeriousAscension]

Prolonged mouth breathing also partially during development leads to poor facial development. What I know of is mouthbreathing leads to a narrow, setback and downwards grown maxilla and a set back madible. It gives a phenotypically look. You can recognize if someone was/is a mouthbreather. What general advice is recommened for victims of mouth breathing?

 

[Acne Victim]

Lefort III