Fungus balls are common causes of sinus disease. In this photograph, a dental implant was improperly placed within the lumen of the maxillary sinus. Typically, a bone graft procedure or "sinus lift" is done prior to the dental implant in order to prevent this type of complication. In this case, bone grafting was not done, and the sinus was seeded with aspergillus, a type of fungus, from the mouth. Over many years a collection of fungus developed in the sinus, along with a bacterial superinfection.
Treatment included endoscopic sinus surgery to remove the fungus infection, and to allow the sinuses to drain properly. In addition, the dental implant will most likely need to be removed and then revised. In addition, on the right side (left side of the photograph) the maxillary sinus has what appears to be an early fungal infection around another dental implant.