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Wormian Bones
Intrasutural Bones

General Considerations

  • Accessory bones within a suture of the skull
  • Most often the lambdoid suture
  • Usually a normal variant occurring in as many as 80% of Asian population
  • Males more frequently affected than females
  • Pathological only when greater than 10 in number or large
  • A larger, single, centrally located intrasutural bone at the junction of the lambdoid suture and sagittal suture is called the os inca
  • They are named after a person (Ole Worm, a Danish anatomist) who described them


Diseases Associated With Wormian Bones

Cleidocranial Dysplasia


Osteogenesis Imperfecta




Down Syndrome


wormian bones

Wormian Bones. Multiple accessory bones (white and blue arrows) are seen
within the lambdoid suture of the skull, characteristic of Wormian bones.

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