Reconstruction Of Craniofacial Bone Defects Research Articles

Advances and Prospects in Materials for Craniofacial Bone Reconstruction.

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

New Antimicrobial Biomaterials for the Reconstruction of Craniofacial Bone Defects

Reconstructive bone surgery of the head and neck could prove challenging in terms of postoperative healing and recovery. Fighting infection during the healing period is one of the critical factors of the long-term survival of an implant. The aim of the study was to develop an innovative composition suitable for an antibacterial craniofacial implant that should have the capacity to continuously and constantly release the amount of gentamicin necessary to prevent the post-surgical infections. For this purpose, a series of composite materials based on dimethacrylic monomers, hydroxyapatite and ZrO2, with (series B) or without the addition of polymethyl methacrylate (series A), reinforced with woven E-glass fibers (FRC) were obtained using the laminate lay-up process. Gentamicin was included in all FRC sample matrices to confer an antimicrobial effect. The results show that after extraction of the residual monomers from the FRC samples in different solvents (chloroform, acetone and ethyl alcohol), the cumulative amount of released gentamicin after 12 days was between 7.05–11.38 mg for A samples and 11.21–14.52 mg for B samples. The microbiological protocol showed that gentamicin induces a two weeks-lasting antimicrobial effect maintained over the minimal inhibitory concentration for P. aeruginosa and S. aureus.

Reconstruction of Craniofacial Bone Defects with Autologous Human Bone Marrow Stem Cells and Autogenous Bone Grafts: A Case Report with Review of Literature.

ABSTRACTReconstruction of craniofacial bony defects has always been a challenging task for the surgeons over the years. The science of reconstructing such defects is of at most importance to craniofacial and plastic surgeons due to its relevance in facial aesthetics function as well as prerequisite procedure for continuing other surgical procedures. The main goal of the reconstruction of the craniofacial defects is to reduce the morbidity by restoring the facial form and aesthetics, as well as a good function of the facial structures by achieving a reasonable occlusion and articulation. Although significant improvements have occurred during the last few decades, challenges still exist as to what type of reconstruction to be carried out with regard to techniques and the type and quality of materials of choice to be used. As decades progressed, the advancement in surgical techniques and the variety of reconstruction methods have definitely improved the quality of life. This article reviews the method of bony reconstruction of craniofacial defects using autologous human bone marrow stem cells and autologous bone grafts and its modification, which includes much recent tissue engineering techniques and regenerative medicine, thereby replacing older techniques by biological substitutes, which can restore improve and maintain orofacial function and aesthetics.

A Novel Method of Neo-osseous Flap Prefabrication: Induction of Free Calvarial Periosteum with Bioactive Glass.

Reconstruction of craniofacial bone defects is a primary focus of craniofacial surgery. Although autogenous bone grafts remain as the gold standard, alloplastic materials have also gained widespread popularity due to their off-the-shelf availability, ease of use, and durability. In addition to replacing the missing bone, some of these alloplastic materials have also been found to induce new bone formation. In this study, the phenomenon of neo-osseous induction with bioactive glass was investigated for different implant-soft tissue configurations. Thirty-two male, Wistar albino rats were divided into four equally numbered study groups. In group 1 (FP), adipofascial groin flaps were prefabricated with free periosteal grafts. In group 2 (FPB), adipofascial groin flaps were prefabricated with free periosteal grafts and bioactive glass. In group 3 (FB), adipofascial groin flaps were prefabricated with bioactive glass. In group 4 (control), adipofascial groin flaps were not prefabricated. Morphometric analyses of the prefabricated structures were performed using micro-CT. The histologic properties of the ectopic ossification were assessed by using a modified scoring system. Group 1 (FP) showed the greatest rate of mature lamellar bone formation. Group 2 (FBP) showed the greatest amount of bone density and volume. However, the addition of bioactive glass in group 2 (FBP) decreased the rate of mature lamellar bone formation when compared with group 1 (FP). Ectopic ossification was not observed in the control group. Bioactive glass can be successfully used in the prefabrication of vascularized compound structures for the reconstruction of complex bone defects. However, interference with the periosteal induction of mature lamellar bone formation should be taken into consideration, especially in pediatric bone defects, which primarily rely on spontaneous osteogenesis through periosteal induction.

Application of Computer-Assisted Design and Manufacturing–Fabricated Artificial Bone in the Reconstruction of Craniofacial Bone Defects

The purpose of this study was to evaluate the clinical application of individual craniofacial bone fabrications using computer-assisted design (CAD)-computer-assisted manufacturing technology for the reconstruction of craniofacial bone defects. A total of 8 patients diagnosed with craniofacial bone defects were enrolled in this study between May 2007 and August 2010. After computed tomography scans were obtained, the patients were fitted with artificial bone that was created using CAD software, rapid prototyping technology, and epoxy-methyl acrylate resin and hydroxyapatite materials. The fabrication was fixed to the defect area with titanium screws, and soft tissue defects were repaired if necessary. The fabrications were precisely fixed to the defect areas, and all wounds healed well without any serious complications except for 1 case with intraoral incision dehiscence, which required further treatment. Postoperative curative effects were retrospectively observed after 6 to 48months, acceptable anatomic and cosmetic outcomes were obtained, and no rejections or other complications occurred. The use of CAD-computer-assisted manufacturing technology-assisted epoxy-methyl acrylate resin and hydroxyapatite composite artificial bone to treat patients with craniofacial bone defects could enable the precise reconstruction of these defects and obtain good anatomic and cosmetic outcomes.

Customized polymethyl methacrylate implants for the reconstruction of craniofacial osseous defects.

Craniofacial defects represent alterations in the anatomy and morphology of the cranial vault and the facial bones that potentially affect an individual's psychological and social well-being. Although a variety of techniques and restorative procedures have been described for the reconstruction of the affected area, polymethyl methacrylate (PMMA), a biocompatible and nondegradable acrylic resin-based implant, is the most widely used alloplastic material for such craniomaxillofacial reconstruction. The aim of this study was to describe a technique for aesthetic and functional preoperative customized reconstruction of craniofacial bone defects from a small series of patients offered by the Brazilian public health system. Three adult male patients attended consultation with chief complaints directly related to their individual craniofacial bone defects. With the aid of multislice computed tomography scans and subsequent fabrication of the three-dimensional craniofacial prototype, custom-made PMMA implants were fabricated preoperatively. Under general anesthesia, with access to the craniofacial defects with a coronal approach, the PMMA implants were adapted and fixated to the facial skeleton with titanium plates and screws. Postoperative evaluation demonstrated uneventful recovery and an excellent aesthetic result. Customized prefabricated PMMA implants manufactured over the rapid prototyping models proved to be effective and feasible.

Computer-Aided Design and Manufacture and Rapid Prototyped Polymethylmethacrylate Reconstruction

This article discusses the application of computer-aided design and rapid prototyping techniques in polymethylmethacrylate reconstruction of craniofacial bone defects. This method avoids the probability of tissue damage due to exothermic reaction during the polymerization process and provides precise implants that exactly fit the defects. A total of 11 patients who have various-sized craniofacial defects underwent polymethylmethacrylate reconstruction. We performed three-dimensional reconstruction and operative design using computer software. According to the design, we determined the shape and size of the implants and made individualized implants for craniofacial bone defects with the rapid prototyping technique. With the application of computer-aided design and a rapid prototyping technique, we could accurately determine the shape, size, and embedding location. Prefabricating the individual implant models is useful in improving the accuracy of treatment. No cases of infection, seroma, extrusion, or contour irregularity occurred as a complication, and all patients were satisfied with the results. During the follow-up period, ranging from 1 to 6 years, all patients remained satisfied, and no complications were sustained. In cases of various-sized cranial defects and complex maxillofacial defects that have enough soft tissue coverage and that do not have contact with a third space, prefabricated methyl methacrylate implants can be used safely. Patients will feel more comfortable if the postoperative shape resembles the original appearance, so the proposed algorithm effectively creates a customized implant.

Reconstruction of craniofacial bone defects with three-dimensional custom-made implants. A five year experience

Reconstruction of craniofacial bone defects with three-dimensional custom-made implants. A five year experience

Osteogenic differentiation of rat bone marrow mesenchymal stem cell after transfection with recombinant pAd-bone morphogenetic protein-7

To study the effect of recombinant pAd-BMP-7 on osteogenic differentiation of rat bone marrow mesenchymal stem cells (MSC). Recombinant pAd-bone morphogenetic protein (BMP) 7 was constructed and the titer of recombinant adenovirus was determined. pAd-BMP-7 and pAdTrack-CMV were used to transfect rat MSC. Transfection efficiency was measured by fluorescent microscope and BMP-7 expression was detected by RT-PCR and immunocytochemical analysis. The MSC were then randomly divided into 3 groups: group A received pAd-BMP-7 transfection, group B was transfected with pAdTrack-CMV, and group C received pAdTrack-CMV transfection plus bone supplements. Osteogenic differentiation of MSC was evaluated by examination of mineralization nodes formation. The titer of pAd-BMP-7 reached about 2.0 x 10(15) pfu/L and transfection efficiency of exogenous gene was nearly 99% at day 2. The expression of exogenous gene sustained about 5 to 7 weeks, with a higher level during first 3 weeks. After transfection, transcription of BMP-7 and expression of BMP-7 protein were also verified in MSC. Compared with the negative results in group B, mineralization nodes were formed in both group A and group C. However, group A showed better formation of mineralization nodes than group C (P < 0.01). The results of this study indicated that recombinant pAd-BMP-7 can successfully transfect rat MSC and accelerate their osteogenic differentiation. The technique explored in this study provides a unique and valuable gene engineering approach for reconstruction of craniofacial bone defects.

Individual prefabricated titanium implants in reconstructive craniofacial surgery: clinical and technical aspects of the first 22 cases.

The reconstruction of craniofacial bone defects by intraoperative modeling of implants restricts the choice of material and its biocompatibility and also reduces the predictability of the aesthetic result. These shortcomings go hand in hand with a prolonged surgical procedure time and increased stress on the patient. In contrast, modern industrial computer-aided design and computer-aided manufacturing systems allow the prefabrication of titanium implants, i.e., individual computer-based three-dimensional models of the bone defect are generated after acquisition, transfer, and evaluation of helical computed tomographic data. Based on these data, the individual shape of the implant is designed using freeform-surfaces geometries and is fabricated by a numerically controlled milling machine in a direct fashion. The conical margins of this implant are designed with a precision of 0.25 mm to the borders of the defect, and the surface contours are generated harmonically to the nonaffected neighboring contours with a constant thickness of 1.5 mm. Individual constructions for fixation with the dimensions of microplates are integrated in this process if screw holes cannot be drilled in thin overlapping implant margins. The reconstruction of 22 posttraumatic, postoperative, or primary cranial and craniofacial defects measuring up to 18 cm was performed using this new method. Wound healing was uneventful in all but one case, although some of the patients had been operated on several times before. The result was always predictable and constant using this highly precise technique, and duration of surgery was reduced dramatically.

Reconstruction of craniofacial bone defects with individual alloplastic implants based on CAD/CAM-manipulated CT-data

Reconstruction of craniofacial bone defects by intraoperative modelling of autogenous or alloplastic materials may cause undesirable results concerning the implant shape or the long-term maintenance of this shape. Furthermore, the use of alloplastic materials to be modelled intraoperatively may result in an inflammatory tissue response. Therefore the question is raised whether CAD/CAM-techniques may be used for the pre-operative geometric modelling of the implant based on helical computed tomography data. A numerically based 3-dimensional model of the skull defect serves as the basis for a freeform-surfaces design of the implant shape, position and thickness, using modelling tools and programmes developed for industrial CAD/CAM. The precise and individual fit of the implant results from generating its margins by the borders of the defect, whereas the implant surface is generated by the geometry of the non-affected neighbouring bone contours. The implant data run a numerically controlled milling machine to fabricate the individual implant. The reconstruction of post-traumatic defects of the forehead, of post-surgical temporal defects after intracranial haemorrhage, and of a parieto-occipital defect due to ablative tumour surgery are presented as the first clinical experiences of this new method.

Split-thickness calvarial autografts reinforced by hydroxylapatite/plaster for craniofacial bone reconstruction

Calvarial or cranial (membranous) bone offers several advantages over the more generally utilized rib, iliac or pelvic (endochondral) autografts for the surgical reconstruction of craniofacial bone defects. Studies in humans showed that fresh autogenous membranous bone placed in soft tissue maintained its original size for several years. Autogenous endochondral bone from rib, ilium or tibia treated in the same manner was resorbed in 8 to 10 months. Later studies were performed in rabbits where membranous bone from the frontoparietal region was compared with endochondral iliac bone, after each had been implanted either subcutaneously or subperiosteally. Seventy-five percent of implanted endochondral bone was resorbed whereas the volume of implanted membranous bone increased after 1 year.

Effects of compression during formation on the microstructure of composite hydroxylapatite/plaster implants for bone reconstruction

Composites of plaster of Paris (PP) and hydroxylapatite (HA) particles are being applied for the surgical reconstruction of craniofacial bone defects and for cosmetic surgery. Two types of HA particles are being employed, the dense sintered ceramic (DHA) and the porous, coralline hydroxylapatite (PHA) particles. Excess water is expressed out of the moistened HA/PP mixture prior to implantation and setting by pressing it in a non-tapered syringe against a glass plate. This results in implants with faster setting times and greater mechanical strengths. It was therefore of interest to compare samples of the compressed versus noncompressed mixtures to see whether or not any changes in their microstructure after setting could be related to these different properties.USG Medical Grade Calcium Sulfate Hemihydrate (which has the lowest mortar consistency of any known plaster) was mixed with an equal weight of Interpore 200 particles (a commercial form of PHA). After moistening with a minimum amount of water, disc-shaped noncompressed samples were made by filling small holes (0.339 in. diameter x 0.053 in. deep) in polypropylene molds with a microspatula.