Diagnostic and Prognostic Value of Indicators of Bone Metabolism Markers in Patients Following Mandibulectomy and Free Fibula Flap Reconstruction with Endosteal Implants.

[PURPOSE] To evaluate and assess the indicators of bone metabolism markers osteocalcin and -Cross-Laps in blood serum as a tool for monitoring bone regeneration and determining the time of implantation in patients after mandibulectomy and reconstruction of a free fibular flap with subsequent endosteal implants.

[MATERIALS AND METHODS] Forty-eight patients in a 6-year period participated in this study, due to resection for tumors. All patients underwent reconstruction with fibula free flap after tumor resection, 4-6 months after osteoectomy, dental implants were installed with further orthopedic rehabilitation. To assess the rate of bone remodeling after transplantation, the content biochemical markers of bone remodeling osteocalcin and -Cross-Laps serum were determined by enzyme immunoassay.

[RESULTS] All 46 fibular free flaps were healed without complications and were survived. A total 326 implants installed, 8 implants failed to osseointegrate, and 6 implants failed after 5 years of loading (peri-implantitis). Success rate of implants after 5 years was 95,7%. In patients before surgery, the mean of osteocalcin levels was 8.5 ng/ml, two months later, there was a sharp increase in the content of osteocalcin by 15.4 ng/ml, after four months reached 24.7 ng/ml, after six months of 28.6 ng/ml, then the indicator began to decrease and after 12 months it was approaching the norm of 14.7 ng/ml. In patients before surgery, the mean level of -Cross-Laps was 0.76 ng/ml, after two months bone transplantation the mean level of -Cross-Laps decreased to - 0.65 ng/ml, after four months the indicator increased and reached of 0.98 ng/ml, after six months the indicator was - 1.56 ng/ml, then these indicators began to decrease and after 12 months, approaching normal values of - 0.87 ng/ml. There is a correlation between different concentrations of osteocalcin or -Cross- Laps and the success rate of implants. Implants were shown to be unsuccessful low concentrations of osteocalcin and high concentrations of -Cross-Laps in serum.

[CONCLUSION] Studies have shown that the long-term survival and success rates of implants placed in the reconstructed areas may guarantee an excellent prognosis of implant-supported prostheses. Bone markers in blood serum osteocalcin and -Cross-Laps can be used to evaluate the rate of bone remodeling, which allows you to determine the time of implantation.