If you breathe through your mouth, the shape of upper jaw will be impacted substantially! The tongue shapes the roof of the mouth, so if you have your tongue in the wrong place, you'll develop a narrow palate. Damian Lewis' smile is a good example of this. He definitely needs myofunctional therapy!
Myofunctional therapy along with appliances like the DNA Appliance, ALF Appliance and Orthotropic appliances can help expand and widen a narrow palate.
Join my Myofunctional Therapy Support Group on Facebook / 738132969697620
My website is http://www.myfaceology.com
Disclaimer The information in this video and on this YouTube channel is not medical advice. Please discuss this information with your doctor or health professional before undertaking anything suggested on this channel.