Displacement of a dental implant into the maxillary sinus: case series.

Dental implants placed in the maxilla risk failure because of the low density of the maxillary bone and the shortness of the maxillary ridge. Moreover, inadequate implant preparation, drilling or installation can easily lead to complications related to the maxillary sinuses. Displacement of dental implants into the maxillary sinus can cause serious complications, but there are few reports of such cases. The aim of this paper is to present three cases of a migrated dental implants into the maxillary sinus: in the first two cases the dental implant was found close to the medial wall of the maxillary sinus and was removed through a surgical approach, whereas in the third case the dental implant was spontaneously expelled from the nasal cavities through the mucociliary clearance. The most frequent adverse effect is the local infection of tissue around the implant. For this reason, implants placed close to the maxillary sinus offer a route for infection from the oral cavity to the sinus. While in some cases implant migration causes sinusitis in other, the patients remain asymptomatic; anyway, the treatment depends on the symptoms of maxillary sinusitis. In the third case the dental implant was spontaneously expelled from the nasal graves. Our report illustrates that a powerful mechanism of mucociliary action can cause relatively heavy objects within the maxillary sinus to migrate naturally to the sinus ostia against gravitational force and then to be expelled from the nasal cavities.