Posterior Dens of the Axis, Superior View

Description

Seen from a superior perspective, the posterior aspect of the dens (odontoid process) of the axis (C2) lies centrally, rising from the vertebral body and narrowing at its base toward the dens-body junction. Posterior to the dens, the vertebral foramen forms a broad channel for the spinal cord, bounded laterally by the superior articular facets of C2 that articulate with the inferior articular facets of the atlas (C1). Anteriorly, the anterior articular facet of the dens faces the fovea dentis on the posterior surface of the anterior arch of the atlas, while the posterior surface of the dens provides the attachment surface for the transverse ligament of the atlas within the atlantal ring. Midline anatomy. Tight tolerances. This angle matters because it clarifies the atlanto-axial pivot: the dens acts as a peg, and the transverse ligament restrains posterior translation of the dens toward the spinal canal. Type II odontoid fractures occur at the base of the dens and are classically unstable, a relationship that becomes obvious when you can judge how little bone separates the fracture site from the canal and how close the dens sits to the ligamentous restraint. Surgeons planning posterior C1 to C2 fixation, or clinicians interpreting CT in trauma, often need this exact spatial logic to understand why displacement patterns predict cord risk. Use this illustration in gross anatomy and neuroanatomy teaching blocks when introducing the atlanto-axial joint, in radiology atlases accompanying axial and sagittal CT reformats of C2, and in spine trauma publications discussing odontoid fracture classification and transverse ligament integrity. It also fits operative anatomy materials covering posterior approaches to C1 to C2 stabilization and the clinical anatomy of cervicomedullary compression. Anatomical accuracy verified by SciePro's Medical Advisory Board.