abnormal cervical atlas morphology cervical vertebral fusion abnormal odontoid process morphology fusion of atlas and odontoid process 2010-10-22T11:38:18Z C1 anterior arch and dens fusion MP:0010701 MPheno.ontology atlas and odontoid process fusion csmith fused atlas and odontoid process fusion of AA and dens the large protuberance that projects upward from the cervical axis (C2), around which the cervical atlas normally rotates, is instead fused to elements of the atlas; the odontoid process may or may not remain attached to the axis