Paranasal sinus mucoceles are benign, locally expansile cystlike masses that are filled with mucus and lined with epithelium. Most occur in the frontal sinus. Maxillary sinus mucoceles are presumably uncommon in the United States and European countries, although they have been frequently reported in Japan, particularly following Caldwell-Luc surgery. Clinical symptoms may not appear for at least 10 years postoperatively. Chronic sinus inflammation and allergic disease are also common causes of paranasal mucoceles. This paper provides an overview of maxillary sinus mucoceles and presents a case study involving a 62-year-old Latin male whose asymptomatic maxillary sinus mucocele was not revealed until he presented for maxillary sinus grafting and implant placement. Schlagwörter: maxillary sinus, mucocele, postoperative maxillary cyst, sinus augmentation, surgical ciliated cyst