Once the pilot drill gets its entrance into the bone (white arrow), the trajectory should be changed (Fig.13 green arrow).  As drills or osteotomes increase their diameter, they also tend to move buccally (red arrow) due to dense and thick palatal bone.

B-L Position

Xin Wei, DDS, PhD, MS 1st edition 01/17/2015, last revision 01/17/2015