Demineralized bone grafts in reconstructive maxillofacial surgery

The problem of developing optimal plastic materials for replacement of jaw defects capable of replacing autogenous bone tissue is one of the central problems in modern maxillofacial surgery. A promising direction in this regard is the use of bone allografts preserved by various methods. The aim of the study was to investigate the osteoplastic properties of demineralized bone grafts (DBG) at transplantation into the mandibular defects in animal experiment and to evaluate the possibilities of their application in clinical practice at reconstructive surgeries on the facial skeleton. Material and methods. 3 series of experiments on 10 dogs were carried out. In the first series the 3×1 cm marginal defects of the mandible were replaced by orthotopic DBG, in the second – by mineralized BG (MBG) preserved by freezing at the temperature –25 °C, in the third – by combined grafts preserved by freezing in combination with DBG. The results of bone grafting were evaluated according to the data of macroscopic, radiologic and histological studies 1, 3, 6, 9 and 12 months after the operation. 143 patients were operated on in the clinic: 45 patients with cavity defects of the jaws after removal of benign tumors and tumor-like formations, 34 patients with injuries of the lower wall of the abdomen in explosive and zygomatic-vertebral fractures, 32 patients with ununited fractures of the mandible complicated by chronic traumatic osteomyelitis, 26 patients with penetrating defects and 6 patients with deformations of the mandible. Results and discussion. Experimental studies have shown that DBG transplanted into the freshly formed defects of the mandible in animals are replaced by the bone regenerate much faster (after 6 and 12 months respectively) and more completely in comparison with MBG. MBG transplantation in combination with DBG contributed to the acceleration of bone formation processes and led to the defect replacement with bone regenerate in 9 months. In clinical practice positive results were obtained in 136 (95.1 %) out of 143 operated patients. Conclusions. DBG is a full-fledged osteoplastic material that can be used for replacement purposes in cavity defects of the jaws, defects of the lower orbital wall of the orbit in explosive fractures of the orbit and zygomatic fractures, in sequestrectomy in ununited fractures of the mandible complicated by chronic traumatic osteomyelitis. In case of mandibular defects with violation of its continuity the transplantation of MCT in combination with DBG is indicated, which creates conditions for preservation of osteoplastic and mechanical properties of the transplanted biomaterial.