Wormian bones

3D reconstruction of the skull, Wormian bones are visible in the seams.

Wormian ossicles are an anatomical variant. These are small bones located in the seams of the cranial vault. The frequency of occurrence varies between 10% in Caucasians, up to 80% in Chinese populations. In healthy individuals, they occur in rather small numbers, but under pathological circumstances the number can be quite significant.

Synonymous names (Latin):

• ossa Wormiana – according to the professor of anatomy in Copenhagen Ole Worm (1588–1655),
• ossa suturarum,
• ossa Incae (when located in the lambda seam) - more often found among the Incas, described here by Aleš Hrdlička (1869–1943).

Although this is an anatomical variant, they are more often associated with certain disease states. In particular, these are the following diseases:

• osteogenesis imperfecta,
• Menkes disease,
• Rickets,
• Down syndrome.

Links

• F.Gailard: Wormian bones. Radiopaedia.org