Axis

Description

Seen in lateral profile, the female skull rests on the upper cervical spine with the atlas (C1) cupping the superior articular facets of the axis (C2) just inferior to the occipital condyles. The dens (odontoid process) rises superiorly from the C2 body, projecting posterior to the anterior arch of C1 and anterior to the spinal canal in normal alignment. Posterior elements of the cervical vertebrae step inferiorly toward C3 and below, while the mandible and maxilla frame the anterior neck, and the hyoid sits inferior to the mandibular body at the level of the pharyngeal airway. One vertebra is color-highlighted to isolate the atlantoaxial complex as the key landmark. Lateral visualization of the dens matters because small changes in the atlantodental interval translate into meaningful instability at C1-C2, with risk to the cervicomedullary junction and upper spinal cord. Odontoid fractures (often Anderson and D’Alonzo type II at the dens base) can be subtle on plain lateral radiographs, so this view helps teach what “normal” alignment should look like before you interpret CT or flexion extension studies. It also maps cleanly onto operative thinking: anterior odontoid screw fixation targets the dens axis line, while posterior C1 lateral mass to C2 pedicle or pars constructs depend on appreciating the posterior arch and C2 isthmus in profile. Small bone. Big consequences. Use this artwork in gross anatomy and neuroanatomy teaching when introducing craniovertebral junction mechanics, in radiology modules on cervical trauma, and in spine surgery texts discussing atlantoaxial instability, rheumatoid pannus, or congenital odontoid anomalies such as os odontoideum. It also fits patient education material where a clear side view helps explain why a cervical collar or C1-C2 fusion is recommended after dens injury. Anatomical accuracy verified by SciePro's Medical Advisory Board.