In dental implantology, various complications, such as maxillary sinusitis, oroantral gap formation, or slippage of the implant into the paranasal sinuses during the treatment of posterior edentulous maxilla with a dental-implant supported prosthesis, have been encountered. Dental implants that have slipped into the maxillary sinus may give rise to infections, such as sinusitis, through contact with the sinus mucosa. Severe cases, such as fungal infections and cancer, have been reported in cases of foreign bodies migrating into the maxillary sinus
1-3. The factors that cause delayed implant slippage into the maxillary sinus include a change in intrasinus pressure and nose pressure, peri-implant bone destruction and infections, and failed osseointegration. In the present case, in which an implant slipped into the maxillary sinus, the implant slippage was due to failed osseointegration and peri-implantitis. Generally, in such cases, the treatment protocol is the removal of the foreign object from the sinus. The treatment options include CLS, the endoscopic technique, or a combination of both
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In the last decade, endoscopic surgery has been undertaken to minimize complications, for example, nerve damage and scars after skin incisions. Barrault 9 was the first to describe the usefulness of endoscopic surgery for diseases of the maxillary sinus, as it removed the need to cut soft tissue and bone in many cases. Kitamura et al. 10 reported a case of endoscopic removal of a dental implant in the sinus using a transnasal approach and reported that the endoscopic surgical approach caused less morbidity than that found with more common methods, such as CLS. Although endoscopic surgery has many advantages, there are also disadvantages associated with this procedure. The first major disadvantage of endoscopic surgery is that the procedure requires specific training, equipment, and general anesthesia. The next main disadvantage is related to the size of the foreign object: If the object is large or accompanied by a dental cyst, it cannot be retrieved using the endoscopic technique. In these cases, the surgeon should consider a classical approach, such as the CLS procedure with local anesthesia 2. In a recent case, Eltas et al. 1 used CLS to remove implants from both maxillary sinuses. Despite the minimally invasive nature of endoscopy, they selected not to use the endoscopic method because of the restricted size of the operative site and the location of the implants (i.e., near the posterior wall of the maxillary sinus). Based on our experience in the present case, CLS appears to be a reliable procedure, which provides superior visibility, with a limited incision, and it respects the integrity of the sinus. Risk factors in traditional intraoral CLS include infraorbital nerve damage, buccal soft tissue retraction, mucosal scar tissue, oroantral gap formation due to incomplete periosteal closure, and inadequate amounts of bone that require placement of a second implamentation 1. We did not encounter any of the above-mentioned complications in this case.
In conclusion, implant displacement into the maxillary sinus or paranasal sinuses is a rare but well recognized complication in dental implantology. In such cases, the implant must be removed, as it may cause a foreign body reaction in the sinus. In cases where the implant is displaced into the posterior or anterior region of the maxillary sinus, it may be difficult to remove. CLS is preferable to endoscopic sinus surgery in such cases for the following reasons: Endoscopic sinus surgery is performed with a small window; it has a limited ability to access the base, posterior, and anterior areas of the maxillary sinuses; and it cannot remove large-sized objects.
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