The bone is felt soft during initial osteotomy (Fig.3).   More importantly the parallel pin is not perpendi-cular to the crest.  Ideally after withdrawal of the pin (Fig.3' black area), the trajectory of the osteotomy Should have been corrected so that the drill is perpendi-cular to the crest (red arrow).

Soft Bone of A Smoker

Xin Wei, DDS, PhD, MS 1st edition 07/13/2015, last revision 07/13/2015