"Normal value for posterior atlantodental interval (PADI) is >15mm7."
Expected headings
"Measurement"
"The anterior atlantodental interval is the horizontal distance between the posterior cortex of the anterior arch of the atlas (C1) and the anterior cortex of the dens in the median (midsagittal) plane 2. Posterior atlantodental interval (PADI) is the horizontal distance between the posterior cortex of the dens to the posterior arch of the C1 in the median (midsagittal) plane."