Answer by  
                                                                                          sunitadas (121)
                                                            
                          
                          
                                                          A sacral dimple is a small hole or divot located just above the buttocks.Atleast 2%of infants born have such type of dimples.This defect occures if the spinal coloumn is not formed properly(when the baby is in mom) i.e it is a malformation in lower layers including the spine and spinal cord.