Sagittal synostosis and ossified scalp hematoma: cause or consequence?

In this paper, the author presents 2 cases of sagittal synostosis with scaphocephaly that featured ossified scalp hematomas straddling the sagittal suture in the midparietal region. These ossified lesions were originally cephalohematomas. Collection of blood under the pericranium across the midline was possible in these cases because sagittal synostosis had obliterated the sagittal suture and its dense attachment to overlying periosteum. Scaphocephaly very likely exacerbated the difficulty of the deliveries and contributed to the causation of the scalp hemorrhages. The alternative hypothesis, that ossification of a scalp hematoma immobilized the suture and caused synostosis, is not tenable for reasons that are reviewed. Sagittal synostosis in these 2 instances was not a complication of birth trauma.