Reconstruction of the mandible using preshaped 2.3-mm titanium plates, autogenous cortical bone plates, particulate cancellous bone, and platelet-rich plasma: a retrospective analysis of 20 patients.

PURPOSE: The purpose of this retrospective study was to evaluate a group of 20 patients who underwent a reconstruction of the mandible by use of free bone grafts and platelet-rich plasma (PRP). MATERIALS AND METHODS: In a period of 8 years, 20 patients underwent a reconstruction of the mandible, by use of preshaped 2.3-mm titanium plates, autogenous cortical bone plates, autogenous particulate bone, PRP, and a special fixation technique. The patients were divided into 3 groups. Group 1 consisted of 10 patients who underwent secondary reconstruction after ablative surgery for malignant tumors. Of these, 4 had preoperative or postoperative radiotherapy. Group 2 comprised 7 patients who underwent primary reconstruction after resections for benign but aggressive odontogenic tumors. Group 3 consisted of 3 patients with severe atrophy and malunion. The defects ranged in size from 8 to 12 cm in groups 1 and 2 and from 2 to 4 cm in group 3, and the follow-up ranged from 1 to 8 years. RESULTS: The initial healing was uneventful in all but 3 patients. In these 3 patients additional bone grafts had to be placed to allow for optimal implant placement. At the time of implant insertion, some areas of granulation tissue were found, possibly because of the rather high dose of PRP used. Continuity in all cases was achieved, and the patients considered the results good in 10 cases and satisfactory in 9 cases. One patient could not be approached for the last assessment. CONCLUSION: The grafting and fixation technique used proved to be rather reliable. The antimicrobial effect and the proliferation of osteoblasts are likely to be responsible for the results achieved.

The effect of platelet-rich plasma in vitro on primary cells: rat osteoblast-like cells and human endothelial cells.

The aim of this study was to evaluate the effects of standardized platelet-rich plasma (PRP) concentrates from 10 human donors on cellular behavior. The standardized PRPs used were fivefold average and fivefold maximum baseline values in whole blood. Both these standardized PRPs were characterized by determining platelet numbers and subsequently growth factor concentrations in activated PRPs, called PRP derivatives. Platelet numbers in both types of standardized PRPs were significantly increased compared with whole blood. Further, both PRP derivatives contained significantly higher concentrations of platelet-derived growth factor-AA, platelet-derived growth factor-AB, and transforming growth factor-beta 1. Vascular endothelial growth factor concentrations were significantly elevated in only the most concentrated PRP derivative. Cell culture experiments with osteoblast-like cells showed that both PRP derivatives stimulated cell proliferation without inducing cell differentiation, whereas tube formation in endothelial cell cultures was significantly increased by adding low volume percentages of PRP derivative (2%–8%). Consequently, it can be concluded that there is no direct relationship between the number of platelets and the level of growth factors released from these platelets. PRP derivatives have the potency to stimulate angiogenesis dose dependently, while lacking the capacity to induce osteogenic differentiation. Yet, the proliferation of osteoblast-like cells can significantly be enhanced by supplementation of PRP derivatives.