Osseous defects in the anterior wall of maxillary sinuses, which might appear as a result of maxillary sinusotomy, cause the retraction of soft tissues into the sinus with a follow-up adhesion to the posterior wall. This results in the obliteration of the sinus with scar tissue, formation of synechia, the obliteration of anastomosis and an increase in disease recurrences rate. We propose a new method of the plastic closure of the defect of the anterior wall of the maxillary sinus to restore the continuity of osseous walls of sinuses, which can be used in ORL clinics, oncological centers or dental clinics. For the first time a fragment made from polyether-polytetrafluorethylene threads was used. This implant has all necessary properties: it is durable, flexible and elastic; it is light and bioinert, it has no negative impact on the body; it is easily treated and is available for the use. We determined exact indications for the plastic closure of the defect of the anterior wall of the maxillary sinus. Using of the implant and the placing it on the muscle-periosteal graft protects it from the contact with the mucous lining of the maxillary sinus. The fixation of this implant not only to the underlying soft tissues but also to the overlying ones, creates a good frame, whereas preliminary sinus sanitation by ultrasound cavitation and layer-by-layer low-frequency ultrasonication of stitches allows slash risks of infecting the plastic material and surrounding soft tissues and, as a result, to reduce the number of recurrences of the disease in patients.