The tooth #30 has severe buccal bone loss (especially mesial, Fig.3) and gingival recession.  An implant is designed to be placed in the mesial socket (Fig.1,2 (CT sagittal section)).  The mesial crest is expected to be resorbed, which may be prevented by mesial sheath barely (Fig.1', 2').

Mesial Sheath     Last     Next

Xin Wei, DDS, PhD, MS 1st edition 05/07/2020, last revision 05/07/2020