Ligament of apex dentis

In the triangular interval between the alar ligaments is another fibrous cord, the ligament of apex dentis (or apical odontoid ligament), which extends from the tip of the odontoid process to the anterior margin of the foramen magnum, being intimately blended with the deep portion of the anterior atlantoöccipital membrane and superior crus of the transverse ligament of the atlas.

It is regarded as a rudimentary intervertebral fibrocartilage, and in it traces of the notochord may persist.