Traumatic atlantoaxial dislocation causing os odontoideum in infants.

The pathogenesis of os odontoideum is still a subject of debate. The authors encountered two infants who had traumatic atlantoaxial dislocation and in whom os odontoideum later developed. One of the infants died of tardive cervical myelopathy secondary to cord compression. The authors present their concept that postnatal development of this abnormality results from fracture of the odontoid.