Since the buccal plate looks thin and the septum is oblique (Fig.2 *), osteotomy starts lingual. In spite of the effort, periimplantitis occurs. The implant may not have been placed deep enough or bone graft may not be have been packed sufficiently buccally.
Xin Wei, DDS, PhD, MS 1st edition 03/09/2017, last revision 02/25/2018