title: Case report 261: os odontoideum (OO).
mesh_terms: D000328:Adult; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging; D001368:Axis, Cervical Vertebra / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D011859:Radiography