Radiographic feature changes in an antral pseudocyst that existed prior to sinus floor augmentation and dental implant placement, 15 years after initial detection - a case report

INTRODUCTION AND IMPORTANCE: Maxillary sinus floor augmentation is acceptable and safe for bone augmentation prior to insertion of dental implants in atrophied maxillary bones. Anatomical variations and lesions of the maxillary sinus, including antral pseudocysts, are common radiological findings that can affect the outcomes of maxillary sinus augmentation. We show the changes in the radiological features of an antral pseudocyst that existed before maxillary sinus augmentation and 15 years after the insertion of dental implants. CASE PRESENTATION: The patient was a 69-year-old male with an unremarkable medical history. The initial orthopantomogram revealed a very large antral pseudocyst in the left maxillary sinus. After upper left second molar extraction and maxillary sinus augmentation, two dental implants were inserted in regions 26 and 27. The pseudocyst had changed radiologically 15 years later, but a biopsy showed no characteristic changes, and the dental implants showed no functional failures. CLINICAL DISCUSSION: We present a case of an antral pseudocyst that was not removed before or during sinus floor augmentation. A debate is ongoing regarding whether antral pseudocysts affect maxillary sinus augmentation, and various strategies have been applied to prevent intraoperative and postoperative complications, including removal of pseudocysts 3–12 months before maxillary sinus augmentation, removal during maxillary sinus augmentation, and leaving them alone when the floor is raised. CONCLUSION: The present case showed a preexisting antral pseudocyst at maxillary sinus floor augmentation and insertion of the implants, which changed radiologically 15 years later, but did not affect the function of the dental implants.