title: Os odontoideum: congenital or acquired. A case report.
mesh_terms: D001368:Axis, Cervical Vertebra / Q000002:abnormalities* / Q000293:injuries; D001270:Cervical Atlas / Q000002:abnormalities* / Q000293:injuries; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male