Association between non-vascularised bone graft failure and compartment of the defect in mandibular reconstruction: a systematic review and meta-analysis

Controversy exists regarding the influence of the graft placement site in the mandible on the success of non-vascularised bone grafts. In this study, we examine the association between the compartment of the mandibular defect and the bone graft failure rate. A systematic literature review and meta-analysis was performed using MEDLINE, Embase, and Cochrane databases. Failure rates according to the compartment of mandibular defect were extracted and analysed by meta-analysis. The Newcastle-Ottawa Scale was used to assess the quality of the studies, and publication bias was evaluated using funnel plots. The search strategy identified 27 publications. After screening, five were selected for review. Based on the result of comparison among these five, we found no significant statistical association between the bone graft failure rate and compartment of mandibular defect, although further investigation of prospective randomised cohort studies is required.

Systemic and Local Biocompatibility Assessment of Graphene Composite Dental Materials in Experimental Mandibular Bone Defect

The main objective of this research is to demonstrate the biocompatibility of two experimental graphene dental materials by in vitro and in vivo tests for applications in dentistry. The novel graphene dental materials, including one restorative composite and one dental cement, were subjected to cytotoxicity and implantation tests by using a rat model of a non-critical mandibular defect. In vitro cytotoxicity induced by materials on human dental follicle stem cells (restorative composite) and dysplastic oral keratinocytes (dental cement) was investigated at 37 °C for 24 h. After in vivo implantation, at 7 weeks, bone samples were harvested and subjected to histological investigations. The plasma biochemistry, oxidative stress, and sub-chronic organ toxicity analysis were also performed. The resulting cytotoxicity tests confirm that the materials had no toxic effects against dental cells after 24 h. Following graphene dental materials implantation, the animals did not present any symptoms of acute toxicity or local inflammation. No alterations were detected in relative organ weights and in correlation with hepatic and renal histological findings. The materials' lack of systemic organ toxicity was confirmed. The outcomes of our study provided further evidence on the graphene dental materials' ability for bone regeneration and biocompatibility.

Combined bilobed trapezius myocutaneous and scapula osteomyocutaneous flaps for the restoration of through-and-through defects of the mandible following salvage surgery for recurrent head and neck tumours

This study was performed to evaluate the outcomes of combined bilobed trapezius myocutaneous and scapula osteomyocutaneous flaps for the restoration of through-and-through defects of the mandible. The subjects were six patients with recurrent malignant tumours who underwent salvage surgeries and reconstruction with combined flaps based on the transverse cervical vessels (TCVs). All patients had combined bone (four type H, one type LCL, and one type C) and extensive soft tissue defects (through-and-through defects) following salvage surgery. All tumours were removed and the complex defects restored successfully. Two patients experienced minor complications: one minor intraoral flap failure and one case of wound dehiscence at the donor site. The appearance of the face and neck was satisfactory or acceptable in all patients. No patient showed severely limited range of motion of the upper limb. The patients were followed up for 10 to 18months. One patient was living with no evidence of disease. The use of combined bilobed trapezius myocutaneous and scapula osteomyocutaneous flaps based on the TCVs may be an effective approach for the restoration of through-and-through defects of the mandible and may provide satisfactory or acceptable functional and aesthetic outcomes following salvage surgery for advanced head and neck tumours.

Current concepts of bone tissue engineering for craniofacial bone defect repair

Craniofacial fractures and bony defects are common causes of morbidity and contribute to increasing health care costs. Successful regeneration of bone requires the concomitant processes of osteogenesis and neovascularization. Current methods of repair and reconstruction include rigid fixation, grafting, and free tissue transfer. However, these methods carry innate complications, including plate extrusion, nonunion, graft/flap failure, and donor site morbidity. Recent research efforts have focused on using stem cells and synthetic scaffolds to heal critical-sized bone defects similar to those sustained from traumatic injury or ablative oncologic surgery. Growth factors can be used to augment both osteogenesis and neovascularization across these defects. Many different growth factor delivery techniques and scaffold compositions have been explored yet none have emerged as the universally accepted standard. In this review, we will discuss the recent literature regarding the use of stem cells, growth factors, and synthetic scaffolds as alternative methods of craniofacial fracture repair.