Changes in graft thickness after skull defect reconstruction with autogenous split calvarial bone graft

Donor Site Changes in Bone Thickness, Volume, and Density Following Split Cranial Bone Graft Harvest

The calvarium can provide large amount of good quality corticocancellous autogenous bone graft. Although many studies have highlighted the advantages of the split cranial bone graft, there is no published work available in the literature about the fate of donor site of the split cranial bone graft. The present study was undertaken to assess the donor site as regards to the thickness, volume, and the density of the residual bone over a period of 12 months in the postoperative period. A total of 30 patients in the age group of 15 to 43 years were studied from January 2015 to January 2016. Postoperative computer tomography scans were taken at 2 weeks, 6 months, and 1 year postoperative to measure the bone thickness, volume, and density at the donor site of the split cranial bone graft harvest. The bone thickness at the donor site showed progressive increase in the thickness over the period of study and the average increase in thickness was about 12.4% at the end of 1 year. The average increase in volume at the donor site was of 2.65% after 12 months. Similarly, the average bone density increased by 3.7% at the end of 1 year. This prospective study conclusively proves that the residual bone at the donor site of the split cranial bone graft harvest site continues to grow in thickness and density over a period of 1 year.

Treatment of Critical-Sized Calvarial Defects in Rats with Preimplanted Transplants

The local environment and the defect features have made the skull one of the most difficult regions to repair. Finding alternative strategies to repair large cranial defects, thereby avoiding the current limitations of autograft or polymeric and ceramic prostheses constitute an unmet need. In this study, the regeneration of an 8 mm critical-sized calvarial defect treated by autograft or by a monetite scaffold directly placed in the defect or preimplanted (either cranial bone transplant or subcutaneous pocket) and then transplanted within the bone defect is compared. The data reveal that transplantation of preimplanted monetite transplant scaffolds greatly improves the skull vault closure compared to subcutaneously preimplanted or directly placed materials. Autografts, while clearly filling the defect volume with bone appear effective since bone volume inside the defect volume is obviously high, but are not well fused to the skull. The preimplantation site has a large influence on the regeneration of the defect. Transplantation of induced bone inside materials has the potential to reduce the need for autograft harvest without damaging the skeleton. This first demonstration indicates that cranial repair may be possible without recourse to bioactives or cultured cell therapies.

In vivo evaluation of chitosan-glycerol gel scaffolds seeded with stem cells for full-thickness mandibular bone regeneration

The aim of this study was to evaluate in vivo bone regeneration, mediated by adipose-derived stem cells (ADSCs), induced to differentiate into osteoblasts and carried by a scaffold gel. In the test group, bone regeneration was mediated by ADSCs, induced to differentiate into osteoblasts, and carried by a scaffold gel. In the control group a scaffold without cells was used. The scaffold, consisting of chitosan and glycerol phosphate, was maintained in situ by a cross-linked resorbable membrane. The osteogenic potential of ADSCs was confirmed by osteocalcin assay and Von Kossa staining performed before implantation. Histological assays detected an initial increase in bone formation in the test group compared with the control group. Microcomputed tomography analysis did not show significant differences between the two groups. Both histological and microcomputed tomography analysis were performed on the ex vivo specimens after a follow-up period of 8 weeks. We observed that differentiated ADSCs could increase bone regeneration and that the scaffold used here can be a suitable carrier to entrap and maintain the cells in situ. On the contrary, the membrane used was not functional in isolating the site of the defect from surrounding soft tissues and caused a significant inflammatory reaction.

Customized acrylic implants for reconstruction of extensive skull defects: an exception approach for selected patients

ABSTRACT Objective: to present our experience in the surgical treatment of extensive skullcap defects with customized acrylic implants. Methods: we conducted a retrospective analysis of patients with extensive skull defects undergoing acrylic cranioplasties between 2004 and 2013. We carefully selected all patients and classified surgical results based on three scales (craniofacial esthetics, improvement of facial symmetry and need for additional surgery). Results: fifteen patients underwent cranioplasty with intraoperative acrylic implants, whether manually customized (46.67%) or made with prototyped three-dimensional biomodels (53.33%). There were two (13.33%) complications (one infection with implant withdrawal and one seroma). We considered the craniofacial aesthetics excellent (50%), the degree of improvement of craniofacial symmetry satisfactory (57.14%), and the overall mean of surgical results according to the need for new surgeries was 1.5±0.52. Conclusion: cranioplasties of patients with extensive skullcap defects should obey careful and predetermined criteria, both for selection and for the acrylic implant customization method.

Clinical application of three-dimensional printing technology in craniofacial plastic surgery

Three-dimensional (3D) printing has been particularly widely adopted in medical fields. Application of the 3D printing technique has even been extended to bio-cell printing for 3D tissue/organ development, the creation of scaffolds for tissue engineering, and actual clinical application for various medical parts. Of various medical fields, craniofacial plastic surgery is one of areas that pioneered the use of the 3D printing concept. Rapid prototype technology was introduced in the 1990s to medicine via computer-aided design, computer-aided manufacturing. To investigate the current status of 3D printing technology and its clinical application, a systematic review of the literature was conducted. In addition, the benefits and possibilities of the clinical application of 3D printing in craniofacial surgery are reviewed, based on personal experiences with more than 500 craniofacial cases conducted using 3D printing tactile prototype models.