It is difficult to use hard tissue landmark (drill stopper) to make osteotomy in the fresh extraction socket because of socket irregularity and hemorrhage.  Once osteotomy is initiated, depth is more reliably controlled with soft tissue landmark (such as gingival margin).  This happens in today's case.  Without CT information, the osteotomy is established in the buccal slope of the septum of the tooth #2 (after extraction) by using alternatively Magic Sinus Lifter and 4.8 mm Magic Drill (MD).  Finally the sinus floor (Fig.1 red dashed line) is lifted after the MD reaches ~16 mm counting from the gingival margin, consistent with preop panoramic X-ray and intraop PA measurement.  The 4.5x11 mm dummy implant is close to the impacted 3rd molar (1).

Soft Tissue Landmark Next

Xin Wei, DDS, PhD, MS 1st edition 11/03/2017, last revision 08/14/2018