In May of 2015 Catalina, Ximena and Scarlett Hernandez-Torres were born in Corpus Christi, Texas. Ximena and Scarlett were conjoined at the pelvis; however, each girl has her own set of legs. One in every two hundred thousand sets of twins could be born conjoined, but even rarer is a set of triplets being born with two of the three babies being conjoined, an occurrence with only a one in 50 million chance of it happening. The doctors in charge of separating the girls have used a virtual 3D model, generated by CT scans and MRI data, of the twins to simulate the surgery. You can read more about this unique medical procedure at 3DPrint.com: https://3dprint.com/129167/conjoined-twins-separation/