Flat occiput UMLS:C4280482 Posterior flattening of the skull Flat back of skull Reduced convexity of the occiput (posterior part of skull). UMLS:C1837402 HP:0005469 Reduced convexity of the occiput gives an appearance of flattening. There are no objective measures for convexity of the occiput, and evaluation depends heavily on the experience of the observer. This finding may or may not be accompanied by Brachycephaly (which should be coded separately), and may be observed more frequently when an infant is placed to sleep on his/her back. Occipital plagiocephaly can result from fusion or sclerosis of the lambdoid suture. If unilateral, this is accompanied by unilateral occipital flattening and bulging of the ispilateral frontal bone. Flat posterior head HP:0000247 Flat posterior cranium HP:0000249 Flat back of the head Flat back of the skull Abnormal occipital bone morphology