Genetic mutation Damage to the fetus or uterus Complications at birth A growth or hormone disorder Reconstructive surgery following a severe injury, e.g. burn injury Arthritis and other rheumatoid disorders Fractured bones left to heal without being properly set (malunion) Chronic application of external forces, e.g. artificial cranial deformation Chronic paresis, paralysis or muscle imbalance, especially in children, e.g. due to poliomyelitis or cerebral palsy