Background and aim: The most common etiology of creating the communication between maxillary sinus and oral cavity is upper premolars or molars extraction. Nowadays most patients expect reconstruction of missing tooth using dental implants. A main factor for successful implant therapy is the presence of an adequate quantity and quality of bone. The aim of this study was to assess the efficacy of the surgical treatment using bone augmentation of the oro-antral perforation (OAP) following maxillary posterior teeth extraction. Methods and materials: The study was performed in 1 patient, woman who was in good health, at age 28. As the OAP was diagnosed after 16 tooth extraction, it was sutured closed by buccal flap method. Three months later 26 tooth was extracted and the OAP was also diagnosed. It was augmented using ksenograft material (Geistlisch Bio - Oss), collagen membrane (Geistlisch Bio - Gide) and sutured closed by the same method. The measure of postoperative defect and bone regeneration progress were conducted basing on CBCT performed 3 days and 6 months after every surgery. Results: Patient had a successful OAP closure and no sinusitis in both sides. Bone thickness after 6 months was 1 mm where 16 tooth was extracted and 11,72 mm on the side, where 26 tooth was extracted. Conclusions: The buccal flap method does not ensure bone regeneration after OAP, but it is effective for closure. The thickness of the regenerated bone after augmentation was satisfactory for implantology treatment. Keywords: oro-antral perforation, oro-antral communication, bone regeneration, buccal flap technique, internal sinus lift, dental implants