There are two common deformities of the anterior chest wall:
Pectus excavatum, also known as 'funnel' or 'sunken' chest is where the breast bone is pushed abnormally inward and the chest appears caved-in or sunken. Funnel Chest affects approximately one in 300 people. There is a 3:1 male to female ratio.
Pectus Carinatum, also known as 'pigeon' chest is where the breast bone is pushed outward. Pigeon chest affects around one in 1,000 people.