Apolinary

“70,000 to 100,000 births; twins joined at the head occur only once in 2 to 2.5 million births. Siamese twins received their name because of the birthplace (Siam) of Chang and Eng (1811 - 1874) whom P.T. Barnum exhibited across America and Europe. Most cranio pagus Siamese twins die at birth or shortly afterward. So far as we know, not more than 50 attempts had previously been made to separate such twins. Of those, less than ten operations have resulted in two fully normal children. Aside from the skill of the operating surgeons, the success depends largely on how much and what kind of tissue the babies share. Occipital cranio pugus twins (such as the Binders) had never before been separated with both surviving.”
― Ben Carson, Gifted Hands: The Ben Carson Story