Mechanical strain induces ex vivo expansion of periosteum.

Segmental bone defects present complex clinical challenges. Nonunion, malunion, and infection are common sequalae of autogenous bone grafts, allografts, and synthetic bone implants due to poor incorporation with the patient's bone. The current project explores the osteogenic properties of periosteum to facilitate graft incorporation. As tissue area is a natural limitation of autografting, mechanical strain was implemented to expand the periosteum. Freshly harvested, porcine periosteum was strained at 5 and 10% per day for 10 days with non-strained and free-floating samples serving as controls. Total tissue size, viability and histologic examination revealed that strain increased area to a maximum of 1.6-fold in the 10% daily strain. No change in tissue anatomy or viability via MTT or Ki67 staining and quantification was observed among groups. The osteogenic potential of the mechanical expanded periosteum was then examined in vivo. Human cancellous allografts were wrapped with 10% per day strained, fresh, free-floating, or no porcine periosteum and implanted subcutaneously into female, athymic mice. Tissue was collected at 8- and 16-weeks. Gene expression analysis revealed a significant increase in alkaline phosphatase and osteocalcin in the fresh periosteum group at 8-weeks post implantation compared to all other groups. Values among all groups were similar at week 16. Additionally, histological assessment with H&E and Masson-Goldner Trichrome staining showed that all periosteal groups outperformed the non-periosteal allograft, with fresh periosteum demonstrating the highest levels of new tissue mineralization at the periosteum-bone interface. Overall, mechanical expansion of the periosteum can provide increased area for segmental healing via autograft strategies, though further studies are needed to explore culture methodology to optimize osteogenic potential.

Bone grafting in maxillofacial trauma.

PURPOSE OF REVIEW: The purpose of this article is to review the recent grafting strategies in maxillofacial trauma. RECENT FINDINGS: Recent technological advancements have applications in the management of maxillofacial trauma; advancements in imaging modalities such as 3D imaging can help surgeons in both the preoperative and intraoperative periods. These may be coupled with navigational systems to further facilitate complex reconstructions. 3D printing has been used in reconstruction and 3D, 4D, and 5D bioprinting technologies continue to improve and to find new uses, and stem cells and growth factors in maxillofacial trauma are also among the most studied topics. Maxillofacial traumas have decreased in number during the COVID-19 pandemic, as more conservative approaches have been preferred in COVID pandemic conditions. SUMMARY: Preoperative planning is the most important step in the reconstruction of maxillofacial trauma defects, and early bone and soft tissue reconstructions are recommended in severe maxillofacial traumas. Autogenous grafts are the gold standard in bone grafting. Nonvascularized grafts are planned according to the size, shape, and location of the defect, with vascularized bone flaps preferred in large defects, wide soft tissue defects, and contaminated defects. Alloplastic grafts or xenografts may be used if autogenous grafts are not available.

Vascularized free fibula flap oral rehabilitation using tissue engineered mucosa: Report of 3 cases.

The aim of this report is to introduce the use of the dermal substitute Integra® in the context of free fibula flap prelamination for mandibular reconstruction. Three cases of mandibular reconstruction with prefabricated and Integra-prelaminated vascularized fibula flaps are reported in this article. The patients reported in this case series presented with the following tumours: an extensive cemento-ossyfying fibroma, a multicystic ameloblastoma and an extensive calcifying epithelial odontogenic tumour. Virtual three-dimensional (3D) planning and 3D-printed cutting guides were used for the mandibulectomies, the flap harvest and the positioning of the implants. The dermal substitute Integra was used for prelamination instead of skin grafts. Treatment of all 3 patients was performed in two stages; the first consisted of the fibula prefabrication (dental implant insertion) and prelamination, and the second consisted of tumor resection and reconstruction with the vascularized implant-bearing fibula flap. Integra was shown to be able to generate complete mucosa-like tissue over the fibula flaps and in the peri-implant areas. The patients have been followed up for 1, 3 and 7 years, respectively, with satisfactory prosthetic, functional and aesthetic results. None of the patients developed peri-implant disease. It was observed that prelamination with the dermal substitute Integra leads to development of mucosal lining with clinical features similar to oral mucosa. In this report of three cases, use of Integra as part of the prelamination and prefabrication process, instead of skin grafts, appears able to clinically generate mucosal lining with avoidance of skin grafts.