Plagiocephaly Plagiocephaly may affect the posterior skull alone. With plagiocephaly, one can see a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape or asymmetry of the posterior skull alone. Positional plagiocephaly Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Rhomboid shaped skull Flat head Asymmetry of the posterior head Rhomboid shaped head UMLS:C4280807 Deformational plagiocephaly UMLS:C1450010 Asymmetry of the posterior cranium UMLS:C4280598 UMLS:C4280597 Flattening of head HP:0001357 UMLS:C0265529 UMLS:C4072830 Flattening of skull Flattening of cranial vault Flat head syndrome Rhomboid shaped cranium Flattening of cranium SNOMEDCT_US:21850008 Asymmetry of the posterior skull SNOMEDCT_US:254024005 HP:0001121 Abnormal calvaria morphology