Except the depth, a 2.5x10 mm mini implant is placed with precision (in trajectory) at #9 (Fig.1-5, middle of pontic).  Confidence using surgical guide for the narrow ridge is enhanced due to placement of two digits against the buccal and palatal plates for tactile sensation.

Guide for Narrow Ridge Next Xin Wei, DDS, PhD, MS 1st edition 10/16/2018, last revision 10/28/2018