HP_0001357 (Plagiocephaly) can be described as follows. Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Also known as: Flat head syndrome, Flattening of cranial vault, Flattening of cranium, Flattening of skull, Rhomboid shaped cranium, Rhomboid shaped skull.