The odontoid process, or dens, is a superior projecting bony element from the second cervical vertebrae (C2, or the axis). The first cervical vertebrae (atlas) rotates around the odontoid process to provide the largest single component of lateral rotation of the cervical spine. Fracture of the odontoid process is classified into one of three types: type I, type II, or type III fractures, depending on the location and morphology of the fracture.