Autologous MMSCs will be isolated from oral mucosa biopsy sample and expanded in vitro.Tissue engineered construction will be created using synthetic tricalcium phosphate and autologous MMSCs. Patients will undergo sinus lift procedure with implantation of created tissue-engineered construction. This is a single arm study with no control. All patients receive cell therapy.

Patients with verified diagnosis partially edentulous maxilla and alveolar bone atrophy will undergo oral mucosa biopsy and autologous MMSCs will be derived and expanded in vitro during 3-4 weeks. After that tissue engineered construction will be created using synthetic tricalcium phosphate and autologous MMSCs. Patients will undergo sinus lift procedure with implantation of created tissue-engineered construction. Six months later patients will undergo dental implant installation. Biopsy of bone tissue at the site of sinus lift will be performed as a part of dental implant installation with subsequent histological analysis of bone specimen.

Inclusion Criteria:

• Partially edentulous maxilla
• Height of the bone tissue in the area of reconstruction 1 - 5 mm according to results of cone-beam computed tomography
• Minimal height of the augmentation - 8 mm
• Volume of bone tissue deficiency of the alveolar process of the maxilla 3 - 5 cm3
• Implant installation scheduled to be at least 6 months after sinus-lift operation
• Patient is familiar with Participant information sheet
• Patient signed informed consent form

Non-inclusion Criteria:

• Chronic and acute ear, nose and throat diseases, including maxillary sinusitis, foreign bodies in the maxillary sinus, odontogenic and not odontogenic maxillary sinus cyst
• Medical history of surgery on maxillary sinuses during preceding 6 months prior to implantation of tissue engineered construction
• Progressive somatic disease (clinically significant diseases of the cardiovascular, hematopoietic or endocrine system, systemic diseases, immunopathological states)
• Patients with malignant tumors including postoperative period, patients receiving chemotherapy and/or radiotherapy
• Any conditions limiting compliance (dementia, neuropsychiatric disease, drug and alcohol abuse etc.)
• Significant weight loss (> 10% of body weight in the previous year) of unknown etiology
• Patient prescribed for any medications with proven effect on bone metabolism
• Diabetes mellitus, disorders of thyroid and parathyroid glands
• Clinically significant abnormalities in results of laboratory tests
• Participation in other clinical trials (or administration of investigational drugs) during 3 months prior inclusion

Exclusion Criteria:

• Patient's refusal from the further participation in trial
• Patient's refusal from compliance with the requirements of contraception during the participation in research
• Plaque index (PI)> 15%
• Sulcus bleeding index (SBI) > 10%
• Chronic kidney disease IV - V stages (creatinine clearance < 30 mL/min estimated by Cockroft-Gault formula)
• Confirmed syphilis, HIV, hepatitis B or C infections

Dropout Criteria:

• Perforation of the Schneider's membrane more than 5 mm on the stage of the sinus-lift operation
• Pregnancy