After 2.2x7.3 mm drill, use 2.2x8.5 and 2.2x10 mm ones (Fig.5). Switch to #2 bone expander (1.3/2.3 mm) and take PA to confirm the depth.  Measure the length of the last drill and #2 expander beforehand.  Continue bone expanders until #5 (3.0/4.4 mm).  Expect less depth as the # of expanders increases.

Graft or Expansion Last Next Xin Wei, DDS, PhD, MS 1st edition 07/20/2019, last revision 08/01/2019