Hi, It seems you are quite worried here young one! But you do not need to worry at all! The mouth breathing has not effected your pretty face at all, as there is no relationship between mouth breathing and the way your face develops. Most people will mouth breathe as a result of some possible obstruction in the nasal passage, usually due to some polyps. There is no harm in mouth breathing, except the down side of having a dry mouth. Many people go through life mouth breathing - and all develop normally,live a normal life and there is no need for any conscious effort to change to nasal breathing.