One of the rarest types of conjoined twins is craniophagus twins, which are joined at the cranium or head. In fact, only 2 percent of all conjoined twins are joined in this way.
Source: Conjoined Twins Facts | University of Maryland Medical Center http://umm.edu/programs/conjoined-twins/facts-about-the-twins#ixzz3IrSCYTBy
University of Maryland Medical Center
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