In os odontoideum, there is a jointlike articulation between the odontoid and the body of the axis, which appears radiologically as a wide radiolucent gap. And its clinical significance lies in its potential to produce serious neurologic sequelae due to atlantoaxial instability. If the condition is suspected, the diagnosis can usually be confirmed on lateral flexion-extension roentgenograms.

We report a patient of os odontoideum, who had paresthesias of all extremities and weakness after trauma.