A 4.5x11 mm implant is placed with insertion torque >60 Ncm (Fig.6), suggesting high bone density.  Why not place an implant at #14?  A 6x11 mm tap is inserted with high torque with thick bone distally (Fig.6 D).  When the tap is removed (Fig.7), there is a lip of bone displaced apical to (but continuously connected to) the distal bone (Fig.6 a black transverse line).  Both * and - are forms of internal sinus lift. A 3.5x3 mm abutment is placed over the implant at the site of #13.

Internal Sinus Lift Perforation

Xin Wei, DDS, PhD, MS 1st edition 05/20/2015, last revision 05/21/2015