The present study aimed to report (1) the sequela of sinus floor elevation (SFE) in the posterior maxilla with severe sinus membrane thickening and an undiagnosed fungal colonization but a patent ostium and (2) a treatment course without implant removal. A 73-year-old woman underwent dental implant placement in the left posterior maxillary area. Although the patient was asymptomatic, severe sinus membrane thickening with Haller cells was observed on a radiographic examination, but the ostium was patent. After SFE and simultaneous implant placement, the patient developed acute sinusitis and was referred to an otolaryngologist. Functional endoscopic sinus surgery (FESS) was performed, resulting in resolution of the infection and salvage of the augmentation and the implant. The histopathologic examination revealed the fungal ball that could not be diagnosed on preoperative dental radiography. During the 2 years after the delivery of the final prosthesis, a significant reduction in membrane thickness was observed. The implants were functioning well. Clinicians should recognize fungal colonization as an etiology of sinus membrane thickening and provide proper pre- and postoperative management, including FESS.
Keywords: functional endoscopic sinus surgery; fungal sinusitis; sinus floor elevation.