Facial deformity is a broad term covering conditions of the facial bones, muscles, and skin that make life difficult for the patient. They include congenital conditions passed down through the generations, and deformations of the face caused by blunt impact and accidents.
They can have natural or non-natural causes. Some people are born with a facial deformity, many of which (such as a hare lip) can be corrected by surgery. Those caused by injury, including when bones or muscles have "set" into a non-natural pattern, can often also be improved by surgical intervention.