Hi! This same question was asked on this board in late June. The thread name is Dip in Chest. What you are referring to is called pectus excavatum. It is the descriptive term for an abnormal formation of the rib cage, in which the distance from the sternum to the backbone is decreased, making the chest look caved-in or sunken. It is a congenital abnormality. I also have this condition. It was confirmed during a chest xray. Hope this helps.