there arer different types of hymen .We are the firts plastic surgeon in the world who have documented different hymen with photographs.You can search net yourself to find different hymens , but you would not get.
Sieve hymen as it is percieved is not so.There are hardly any hole in hymen.Sieve hymen actually is one in which hymeneal mucous membrane arises at different levels from vagina and creates different holes
