The 4 mm dummy implant is palatally displaced in a flapless manner (Fig. 4A (occlusal view) blue circle).  Release incision confirms the deviation.  A new osteotomy is established with 1.6 mm pilot drill in the middle of the site (red circle).  Distal to the new osteotomy is the incompletely healed socket (brown circle). 

As the osteotomy is enlarged by ME until 4.3 mm and placement of 4.5 and 5.0 mm dummy implant and of 5.5x9 mm definitive one (Fig.4B large red circle), the osteotomy gradually deviates distopalatally. 

Introspectively, the new osteotomy should have been placed more buccomesially (Fig.4C red circle) so that the final osteotomy may end up normally (Fig.4D large red circle). 

How to Avoid Osteotomy Deviation

Xin Wei, DDS, PhD, MS 1st edition 11/28/2016, last revision 11/28/2016