A skull X-ray of an infant or small child may show wormian bones, which are named for the Danish anatomist Olaus Worm. A child with wormian bones should be carefully examined for neurologic deficits and congenital anomalies.


Synonym: ossa suturarum


Features of wormian bones:

(1) accessory bones (ossification centers) in the suture lines and/or within the fontanelles

(2) may range from 1 to 100+ in number

(3) numbers decrease with age as sutures and fontanelles close


According to Pryles and Khan, wormian bones are a marker of abnormal CNS development, which may or may not be immediately evident.



(1) mental retardation

(2) congenital anomalies

(3) hydrocephalus


Conditions associated with multiple wormian bones:

(1) Down's syndrome

(2) osteogenesis imperfecta

(3) progeria

(4) congenital hypothyroidism

(5) cleidocranial dysostosis

(6) hypophosphatasia

(7) pyknodysostosis

(8) pachydermoperiostosis

(9) Hajdu-Cheney syndrome


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