Endonasal endoscopic medial maxillectomy usually includes removal of the inferior turbinate (IT) even if it is not involved in the disease. A surgical approach is presented in which the IT is temporarily excised and then reinserted, followed by postoperative occlusion of the nose for at least 2 weeks. A retrospective case series of 12 patients with inverted papilloma (IP) of the maxillary sinus (Krouse II-III) and 2 patients with 3 mucoceles of the maxillary sinus after a Caldwell-Luc operation were reviewed. After a follow-up period of 12-80 months (28 months on average) all patients underwent endoscopy, and in four cases, additionally, an MRI was performed. There was no recurrence of tumor or mucocele after 12-80 months. The IT and its important function for warming and humidifying the inhaled air could be preserved up to now in all 15 operated sides. The patients did not have any specific pain postoperatively and there was no postoperative bleeding. They all tolerated occlusion for 2-4 weeks. Two patients developed mucoceles due to the formation of scar tissue after endonasal tumor surgery. In three cases of endonasal endoscopic Denker operation patients reported some degree of numbness or irritation of the ipsilateral frontal teeth. The IT can be preserved in endonasal endoscopic medial maxillectomy for treatment of IP without a higher incidence of tumor recurrence. Aftercare should specifically focus on preventing the development of mucoceles caused by scarring.