[Endoscopic removal of a dental implant displaced into the maxillary sinus: A case presentation and a review of the literature].

Accidental implant displacement into the maxillary sinus is often due to inappropriate surgical planning or technique, unrecognised sinus disease, failure to recognise low residual bone quality and quantity during implant-supported maxillary molars and premolars rehabilitation. Secondary implant migration can be attributed to the risk of failing osteointegration due to unnoticed sinus membrane rupture during surgery, incomplete soft tissue closure over the implant's site, preexistent sinus ventilation problems. In this study, we present the case of a patient with a symptomless preexistent sinus infection, which had been treated with functional endoscopic sinus surgery. After the healing period, the following two-stage procedures were performed: 1) maxillary sinus bone augmentation, 2) 6 months later dental implant placement, based on a routine orthopantomogram. At the end of the 4-month planned healing period, the implant displacement was noticed in the sinus cavity. The implant was removed with a combination of endoscopic surgery, transnasal and transoral Luc-Caldwell approach. The possible reasons for displaced implant into the sinus cavity, the treatment decision tree and lessons we learned, updated by the international literature, are discussed. Our recommendation for displaced implant removal is primarily transnasal under general anaesthesia. In the case of the implant in the anterior recess of the maxillary sinus, the functional endoscopic sinus surgery through the prelacrimal recess approach seems to be the preferred approach. A transoral approach should be the chosen method in the case of present oro-anthral fistulae or recent sinus bone graft, when the infected graft should also be removed. Orv Hetil. 2022; 163(13): 527-533.