Master the Subluxation Challenge 2026 – Align Your Path to Success!

To assess how the occiput sits relative to the atlas along the Z-axis, you need a projection that clearly shows the atlanto-occipital junction and the dens. The open-mouth view (APOM) achieves this by opening the atlas ring and letting the dens and the anterior arch of C1 be visualized without the overlying skull obscuring them. In this view you can directly compare the alignment of the occipital condyles with the atlas, so you can tell if there’s superior/inferior or rotational misalignment along that axis. Other views don’t image this region as clearly: AP cervical and AP skull miss or obscure the atlas–occipital relationship, and the lateral cervical view shows sagittal alignment of the lower cervical spine rather than the occipito-atlantal junction.