Abnormal calvaria morphology Abnormal bone structure Decreased calvarial ossification HP:0002701 HP:0002702 A hypomineralised skull castes little or no acoustic shadow on prenatal ultrasound. This makes visualization of the intracranial anatomy clearer than normal. In conditions associated with profound hypomineralisation, the skull shape can be distorted by pressure from the ultrasound transducer later in pregnancy. HP:0005454 Skull soft on palpation Soft skullcap Soft calvaria Undermineralized calvarium Poorly ossified calvarium HP:0005474 Poorly ossified calvaria Abnormal reduction in ossification of the calvaria (roof of the skull consisting of the frontal bone, parietal bones, temporal bones, and occipital bone). UMLS:C1833762 HP:0005471