This is a great book! I have learned so much from it. I ordered it because I have TMJ disorder. I even changed the way I sleep and my pillow. It helps you to be more aware of your posture and even how you chew and exercise also. It has helped me so much. It has helped my husband with his headaches also….. I think everyone should read this book whether or not you have TMJ disorder or not…. Very informative..