What is pectus carnivatum?

Boat chest: Sternums are almost as variable as noses. Some folks' sternums (breastbones) are depressed like the keel of a boat. Nowadays this is treated surgically which improves looks and function.

Pigeon chest: Chest wall deformities come in two flavors. Excavatum or funnel chest is a sunken defect that can affect the heart and lungs resulting in decreased excercise tolerance. Carinatum is a defect that protrudes outward. It does not affect the heart or lungs but can be just as self concious as excavatum. Excavatum can be fixed with a nuss procedure. Carinatum can be fixed with use of an external brace.