Anterior Fontanelle Wormian Bone/ Fontanellar Bone: A Review of this Rare Anomaly with Case Illustration.

Wormian bones are a relatively rare skeletal anomaly that present as accessory bone(s) within the sutures of the cranium and even more rarely within the fontanelles. It is believed that they arise from the formation of abnormal cranial ossification centers. Although not extensively reported in the literature, this anomaly is thought to be associated with other anatomical anomalies such as osteogenesis imperfecta, rickets, and other bone dysplasias. When located within the fontanelles, the most likely site of occurrence is the posterior fontanelle. This case report describes a rare incidence of wormian bone within the anterior fontanelle of an infant who had concurrent craniosynostosis. More research and reporting of this anomaly is necessary to verify any correlated syndromes, and determine the underlying etiology.