Absent dens on submentovertex view of the skull: new sign of an abnormal odontoid.
Anomalies of the dens are clinically important and should be recognized by the radiologist. Frequently, skull, sinus, and facial examinations are performed that include projections of the upper cervical spine. The odontoid may not be readily apparent on these examinations. The absence of a recognizably normal dens on a submentovertex (SMV) projection of the skull has not been previously described. A one-year retrospective review of 425 examinations that included the SMV projection was carried out. In 421 the normal dens was easily recognized on the SMV view of the skull. Lack of identification in the other four indicated a dens abnormality and warranted further investigation.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001368:Axis, Cervical Vertebra / Q000002:abnormalities*; D006801:Humans; D008875:Middle Aged; D009809:Odontoid Process / Q000002:abnormalities* / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012886:Skull / Q000000981:diagnostic imaging*; D013679:Technology, Radiologic; D014057:Tomography, X-Ray Computed