Abnormality of the head Abnormal skull morphology HP:0000929 An abnormality of the skull, the bony framework of the head which is comprised of the neurocranium (with eight cranial bones) and the viscerocranium (facial skeleton) that comprises fourteen facial bones with the mandible as its largest bone. Abnormality of the skull bones UMLS:C0235942 Abnormality of the skull Abnormal skeletal morphology