Fig.4 Look at the vertical green line.  The bone on its right is denser and more rigid (whiter in CT) than that on the left.  When we drive a thin chisel along the vertical green line (yellow), the bone on the left (more pliable) starts to move left a little bit (arrows), back to original article

Xin Wei, DDS, PhD, MS 1st edition 04/10/2011, last revision 01/19/2018