Minimally invasive endoscopic middle meatal antrostomy for the prevention of maxillary sinusitis in association with dental implantation in the posterior maxilla--a proposal.

Penetration of the maxillary sinus floor membrane during sinus lift occasionally induces maxillary sinusitis. However, maxillary sinusitis may still develop even when its floor membrane has been kept intact during such procedures. The decisive factor for the occurrence of maxillary sinusitis is not the integrity of the membrane; more important is the patency of the maxillary sinus natural ostium. The occlusion of the natural ostium presumably results from the expansive edema of the sinus membrane induced by surgical manipulations to the maxillary sinus floor. We propose a minimally invasive endoscopic sinus surgery which conceivably is useful to prevent potential occlusion of the natural ostium associated with maxillary sinus floor augmentation procedures. Although our technique is not a new concept, this is the first report to propose this kind of procedure as an adjunct to dental implantation. Our method is cost-effective and can be performed under topical anesthesia as a same-day surgery. In addition, it brings about no serious complications, such as orbital injuries or cerebrospinal fluid leakage. It aims to correct anatomical deviations, such as septal deviation, concha bullosa, hypertrophied uncinate process, and excessively pneumatized ethmoid bulla, all of which precipitate the occlusion of the natural ostium. Our method consists of a combination of resection of the uncinate process, widening of the natural ostium, and excision of the anterior and inferior edge of the middle turbinate. First, the anterior and inferoposterior segments of the uncinate process are resected with a curved rongeur, leaving the agger nasi cell intact (caution must be exercised to avoid injury to the nasolacrimal duct). This enables visualization of the maxillary natural ostium. The ostium is widened in all directions, using a forceps and/or a scalpel. The resultant widened ostium is bordered anteriorly by the nasolacrimal duct, inferiorly by the base of the inferior turbinate, posteriorly by the anterior surface of the ethmoid bulla, and superiorly by the medio-inferior angle of the orbit. Then the anterior and inferior edge of the middle turbinate is trimmed to prevent its adhesion to the lateral nasal wall or narrowing of the middle meatus. This surgery does not cause cerebrospinal fluid leakage and, at the same time, minimizes the risk for olfactory dysfunction. The antrostomy window thus formed is large enough to secure drainage and ventilation of the maxillary sinus. Moreover, the middle meatus, now deprived of the antero-inferior aspect of the middle turbinate, enables the patient to irrigate the maxillary sinus with a saline solution at home. Septal deviation can also be corrected simultaneously, if postoperative packing of bilateral nasal cavities is tolerable to the patient. Our experiences in treating over 100 patients are encouraging; although postoperative care such as irrigation of the maxillary sinus at home was mandatory and the start of dental implantation was delayed for 2-6 months, no patient who underwent surgery at our clinic developed maxillary sinusitis during the following course of dental implantation. We believe that collaboration between the otorhinolaryngologist and the dentist/oral surgeon is required to minimize the risk of maxillary sinusitis associated with dental implantation in the maxilla.