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Background: This study aimed to investigate the biomechanical behaviors of polyether ether ketone (PEEK) and traditional materials (titanium and fiber) when used to restore tooth defects in the form of prefabricated post or customized post via computational modelling. Methods: First, the prototype of natural tooth, and the prototypes of prefabricated post and customized post were established, respectively, whilst the residual root was restored with dentin ferrule using reverse engineering methods. Then, the stress and strain of CFR-PEEK (PEEK reinforced by 30% carbon fiber) and pure PEEK (PEEK without any reprocessing) post were compared with those made in traditional materials using the three-dimensional finite element method. Results: From the stress point of view, compared with metal and fiber posts, CFR-PEEK and pure PEEK prefabricated post both demonstrated reduced post-core interface stress, post stress, post-root cement stress and root cement stress; moreover, CFR-PEEK and pure PEEK customized post demonstrated reduced post stress, post-root cement stress and root cement stress, while the strain of CFR-PEEK post was the closest to that of dentin. Conclusions: Compared with the traditional posts, both the CFR-PEEK and pure PEEK posts could reduce the risk of debonding and vertical root fracture, whether they were used as prefabricated posts or customized posts, but the biomechanical behavior of carbon fiber-reinforced CFR-PEEK restorations was the closest to dentin, no matter if they were used as prefabricated post or customized post. Therefore, the CFR-PEEK post could be more suitable to restore massive tooth defects. Pure PEEK needs filler reinforcement to be used for post-retained restoration.

This article describes a digital workflow for fabricating an interim obturator after partial maxillectomy which utilizes the radiopacity of iodoform gauze, a common surgical packing material, to simulate postoperative oronasal defect cavities through a computer-aided design and computer-aided manufacturing (CAD-CAM) workflow and to generate the interim obturator by 3-dimensional printing. This technique may serve as a promising alternative technique for the fabrication of an interim obturator and, in particular, benefit patients who have not seen a prosthetic specialist before surgery and present without a surgical obturator.

The dysregulation of immune system plays a crucial function in periodontitis development. Pro-inflammatory cytokines are thought to be critical for the generation and development of periodontitis. The enhanced activity of osteoclasts contributes to periodontitis pathogenesis. Nuclear factor-κB (NF-κB) signaling pathway directly enhances osteoclast differentiation and maturation. 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) is a IκB kinases (IKK) inhibitor. This research aimed to investigate whether TPCA-1 had influence on the pathogenesis of chronic periodontitis. Mouse chronic periodontitis was induced by an in vivo ligature-induced periodontitis model. TPCA-1 was intravenously injected into mice after chronic periodontitis induction. Bone marrow-derived macrophages were cultured in macrophage colony-stimulating factor (M-CSF)-conditioned media with receptor activator of nuclear factor-kappa B ligand (RANKL) induce in vitro osteoclast differentiation. Western blot was used to analyze protein levels and mRNA levels were analyzed through qRT-PCR. TPCA-1 promoted osteoclastogenesis and osteoclast-related gene expression in vitro. The production of pro-inflammatory cytokines in osteoclasts induced by lipopolysaccharides was inhibited by TPCA-1 in vitro. In vitro TPCA-1 treatment inhibited Aggregatibacter actinomycetemcomitans (A.a)-induced expression of pro-inflammatory cytokines and NF-κB signal activation in osteoclasts. The induction of chronic periodontitis was inhibited by the absence of IKKb in mice. This research demonstrates that the treatment of TPCA-1 negatively regulates inflammation response and inhibits the osteoclastogenesis through the inactivation of NF-κB pathway in mouse chronic periodontitis model.

Background: In this study, we evaluated the effect of periodontal splints made from different materials on the stress distributions in compromised periodontal tissues and cement layers, using a computer simulation of mastication. Methods: Twenty-five 3D models were created for a segment of mandibular teeth with different periodontal splints bilaterally extended to the canines. The models were divided into five groups according to the different materials and thicknesses (mm) of the splints: the non-splinted group, PEEK 0.7 group, PEEK 1.0 group, FRC group, and titanium group. Each group was subdivided based on five bone loss levels. Tooth 41 of each model was subjected to vertical and oblique (θ = 45°) static loads of 100 N, respectively, onto the incisal edge. The von Mises stresses and maximum principal stress were analyzed using Abaqus software. Results: Oblique loading resulted in higher stresses on periodontal tissues, cement layers, and splints than those caused by vertical loading. The lower the supporting bone level, the greater the stress difference between the splinted groups and the non-splinted group. In model 133,331, with severe bone loss, the maximum von Mises stress values on the alveolar bone in tooth 41 under oblique loading dramatically decreased from 406.4 MPa in the non-splinted group to 28.62 MPa in the PEEK group and to 9.59 MPa in the titanium group. The four splinted groups presented similar stress distributions in periodontal tissues. The lowest stress level on the splint was observed in the PEEK 0.7 group, and the highest stress level was transferred to the cement layer in this group. Stress concentrations were primarily exhibited at the connectors near the load-carrying area. Conclusions: The tested splinted groups were all effective in distributing the loads on periodontal tissues around splinted teeth with similar patterns. Using splinting materials with low elastic moduli reduced the stress concentration at the splint connectors, whereas the tensile stress concentration was increased in the cement layer. Thus, the use of adhesive cement with a higher elastic modulus is recommended when applying less rigid PEEK splints.

The objective of this study was to evaluate facial soft and hard tissue changes, individually and relative to each other, in patients with skeletal class III deformity after bimaxillary surgery using three-dimensional (3D) photos obtained by white light scanning. Thirty patients with skeletal class III deformity who underwent bimaxillary surgery were selected. Each patient underwent white light scanning and spiral computed tomography (CT) within two weeks before (T0) and six months after surgery (T1). The 3D photos were registered with CT soft tissue models for T0 and T1, and the skeletal area unaffected by treatment (cranial base) was used to register T0 and T1. Then, the 3D colour-coded map was analysed to assess both skeletal and soft tissue changes between T0 and T1. Changes in the 3D coordinates of each anatomical landmark were analysed using the Student's t-test. Maxillary advancement by 2-3 mm and mandibular recession by 5-6 mm were observed; the mandible was shortened in the vertical direction. Compared with the preoperative values, the nasal columella was 0.51 mm shorter, the upper lip was 0.71 mm longer, the base of the alar cartilage was 1.38 mm wider, and the nasolabial angle became larger. The ratio of change in the position of soft tissue point Sn to hard tissue point A was 0.73:1, and that of soft tissue point Pg to hard tissue point Pog was 0.86:1. Images obtained by structured white light scanning registered with CT can be used as an alternative to study facial changes after orthognathic surgery.

The fully digital workflow for an immediate implant-retained auricular prosthesis procedure included computer-aided treatment planning, flapless surgery, and the prefabricated auricular prosthesis rehabilitation. This technique also encompassed the presurgery fabrication of the substructure of the implants and the definitive auricular prosthesis to ensure the smooth insertion of the ear prosthesis.

The high-performance thermoplastic polyetheretherketone (PEEK) has excellent mechanical properties, biocompatibility, chemical stability, and radiolucency. The present article comprehensively reviews various applications of PEEK in removable dental prostheses, including in removable partial dentures (RPDs) (frameworks and clasps), double-crown RPDs, and obturators. The clinical performance of PEEK in removable dental prostheses is shown to be satisfactory and promising based on the short-term clinical evidence and technical complications are scarce. Moreover, the accuracy of RPDs is a vital factor for their long-term success rate. PEEK in removable dental prostheses is fabricated using the conventional lost-wax technique and CAD/CAM milling, which produces a good fit. Furthermore, fused deposition modeling is considered to be one of the most practical additive techniques. PEEK in removable prostheses produced by this technique exhibits good results in terms of the framework fit. However, in light of the paucity of evidence regarding other additive techniques, these manufacturers cannot yet be endorsed. Surface roughness, bacterial retention, color stability, and wear resistance should also be considered when attempting to increase the survival rates of PEEK removable prostheses. In addition, pastes represent an effective method for PEEK polishing to obtain a reduced surface roughness, which facilitates lower bacterial retention. As compared to other composite materials, PEEK is less likely to become discolored or deteriorate due to wear abrasion.

Background Radiation exposure negatively affects the regenerative ability and makes reconstruction of bone defects after tumor section difficult. miR-34a is involved in radiation biology and bone metabolism. The aim of this study was to investigate whether miR-34a could contribute to bone regeneration in irradiated bone defects. Methods The expression of miR-34a was analyzed during the osteoblastic differentiation of irradiated BMSCs and bone formation in irradiated bone defects. miR-34a mimics and miR-34a inhibitor were used to upregulate or suppress the expression of miR-34a in BMSCs irradiated with 2 or 4 Gy X-ray radiation. In vitro osteogenesis and subcutaneous osteogenesis were used to assess the effects of miR-34a on the osteogenic ability of radiation-impaired BMSCs. Collagen-based hydrogel containing agomiR-34a or antagomiR-34a were placed into the 3-mm defects of irradiated rat tibias to test the effect of miR-34a on bone defect healing after irradiation. Results miR-34a was upregulated in the process of bone formation after irradiation. Transfecting radiation-impaired BMSCs with miR-34a mimics enhanced their osteoblastic differentiation in vitro by targeting NOTCH1. Overexpression of miR-34a enhanced the ectopic bone formation of irradiated BMSCs. In situ delivery of miR-34a promoted bone regeneration in irradiated bone defects. Conclusions miR-34a promoted the osteoblastic differentiation of BMSCs and enhanced the ectopic bone formation after irradiation. miR-34a promoted bone defect healing in irradiated rat tibias. miR-34a-targeted therapy might be a promising strategy for promoting the reconstruction of bone defects after radiotherapy. Electronic supplementary material The online version of this article (10.1186/s13287-019-1285-y) contains supplementary material, which is available to authorized users.

For a patient with a unilateral orbital defect, an esthetic orbital prosthesis plays an essential role in enhancing quality of life. This technique describes the combined use of a facial scanner and an intraoral scanner to acquire the digital scan for the design and fabrication of an orbital prosthesis. The method results in an esthetic prosthesis with accurate skin texture reproduction.

Dentin is a suitable scaffold for tooth tissue engineering and can provide the appropriate combinations and concentrations of bioactive proteins to accommodate odontogenic cells. Freeze drying is a possible strategy to treat dentin because it ensures long-term stability of biopharmaceutical products and can increase the stability of dentin for improved distribution and storage. We hypothesized that freeze-dried dentin matrix (FDDM) constitutes a novel bioinstructive scaffold for tooth tissue engineering.This study used a modified technique to prepare an FDDM that preserved the mechanical and biological properties of dentin. The compression resistance and microhardness of FDDM were determined. Similarly, various biological characteristics, including cell morphology, cell proliferation, collagen secretion, alkaline phosphatase activity, and gene and protein expression, were investigated. To assess the inductive capacity of FDDM in vivo, FDDM and human dental pulp stem cell (DPSC) sheets were subcutaneously implanted in the dorsal pockets of nude mice. At 8 weeks postimplantation, the transplants were removed and histologically studied.The results show that FDDM has mechanical and biological characteristics similar to those of dentin (P.05). DPSCs cultured on FDDM and dentin showed superior attachment, growth, viability, and collagen secretion capacity but decreased mineral capability compared with DPSCs cultured with alpha minimum essential medium or hydroxyapatite (P.05). The histologic results show that FDDM, which is similar to dentin, supported dentin/pulplike tissue regeneration in vivo as shown by the related expression levels of dentin markers, such as dentin sialoprotein and alkaline phosphatase.These results suggest that FDDM constitutes a novel superior scaffold for tooth tissue engineering.

Figure S1. Characterization of BMSCs. Figure S2. The miRNA transfection efficiency and effect. Figure S3. miR-34a overexpression enhanced the osteoblastic differentiation of 4â Gy irradiated BMSCs in vitro. Figure S4. The siRNA transfection efficiency and effect. Figure S5. Distribution of agomiR in the bone defect area. Figure S6. Expression of miR-34a in the newly formed bone after implantation of miRNA delivery hydrogel. (DOCX 2001 kb)

Xi Chen,1 Shizhu Bai,1 Bei Li,2 Huan Liu,1 Guofeng Wu,1 Sha Liu,3 Yimin Zhao1 1State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, 2State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Oral Diseases, Center for Tissue Engineering, School of Stomatology, 3Department of Plastic and Reconstructive Surgery, Xijing Hospital, The Fourth Military Medical University, Shaanxi, People’s Republicof China Introduction: Periodontitis is a chronic infectious disease and is the major cause of tooth loss and other oral health issues around the world. Periodontal tissue regeneration has therefore always been the ultimate goal of dentists and researchers. Existing fabrication methods mainly focused on a top–down tissue engineering strategy in which several drawbacks remain, including low throughput and limited diffusion properties resulting from a large sample size. Gelatin methacrylate (GelMA) is a kind of photocrosslinkable and biocompatible hydrogel, with the capacities of enabling cell encapsulation and regeneration of functional tissues. Here, we developed a novel method to fabricate GelMA/nanohydroxylapatite (nHA) microgel arrays using a photocrosslinkable strategy. The viability, proliferation, and osteogenic differentiation and in vivo osteogenesis of human periodontal ligament stem cells (hPDLSCs) encapsulated in microgels were evaluated. The results suggested that such microgels provide great potential for periodontal tissue repair and regeneration. Methods: Microgel arrays were fabricated by blending different weight ratios of GelMA and nHA. hPDLSCs were encapsulated in GelMA/nHA microgels of various ratios for a systematic evaluation of cell viability, proliferation, and osteogenic differentiation. In vivo osteogenesis in nude mice was also studied. Results: The GelMA/nHA microgels exhibited appropriate microarchitecture, mechanical strength, and surface roughness, thus enabling cell adhesion and proliferation. Additionally, the GelMA/nHA microgels (10%/2% w/v) enhanced the osteogenic differentiation of hPDLSCs by elevating the expression levels of osteogenic biomarker genes, such as ALP, BSP, OCN, and RUNX2. In vivo ectopic transplantation results showed that GelMA/nHA microgels (10%/2% w/v) increased mineralized tissue formation with abundant vascularization, compared with the 1%, 3%, and the pure GelMA group. Conclusion: The GelMA/nHA microgels (10%/2% w/v) facilitated hPDLSCs viability, proliferation, and osteogenic differentiation in vitro and further promoted new bone formation in vivo, suggesting that the GelMA/nHA microgels (10%/2% w/v) provide great potential for periodontal tissue regeneration. Keywords: periodontal ligament stem cells, gelatin methacrylate, nanohydroxyapatite, microgel array, differentiation, periodontal tissue regeneration

Numerous preclinical and clinical studies have focused on the periodontal regenerative functions of enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs) of developing porcine teeth. In this study, periodontal ligament (PDL) stem cells (PDLSCs) were isolated, and the effects of EMD on the extracorporeal induction process and the characteristics of PDLSC sheets were investigated for their potential as a more effective stem-cell therapy. EMD-enhanced cell sheets could be induced by complete medium supplemented with 50 μg/mL vitamin C and 100 μg/mL EMD. The EMD-enhanced cell sheets appeared thicker and more compact than the normal PDLSC sheets, demonstrated more layers of cells (3-7 layers), secreted richer extracellular matrix (ECM), showed varying degrees of increases in mRNA expression of periodontal tissue-specific genes (COL I, POSTN), calcification-related genes (RUNX2, OPN, OCN) and a cementum tissue-specific gene (CAP), and possessed a better mineralization ability in terms of osteogenic differentiation in vitro. These EMD-enhanced cell sheets may represent a potential option for stem-cell therapy for PDL regeneration.

OBJECTIVE: To investigate the changes of facial soft tissue before and after orthognathic surgery in patients with skeletal Class Ⅲ malocclusion. METHODS: Between August 2016 and April 2017, 30 patients with skeletal Class Ⅲ malocclusion who underwent maxillary LeFort Ⅰ osteotomy and sagittal split mandible osteotomy were selected as study subjects. Among them, 11 were male and 19 were female with an average age of 22.6 years (range, 18-35 years). Full head CT scan and facial soft tissue three-dimensional image scan were performed within 2 weeks before surgery and at 6 months after surgery. A three-dimensional facial image model was established using Artec Studio 11.0 and CMF Proplan 3.0 software to analyze the facial soft tissue changes before and after surgery. The soft tissue anatomical landmarks in each area of the face were measured and compared before and after surgery. RESULTS: The area of facial soft tissue change after surgery was the maxillary nose and the lower jaw area, and the two sides did not exceed the vertical boundary of the outer canthus. After surgery, the horizontal points of bilateral alar bases and bilateral cheeks changed significantly (P

Background The reconstruction of bone defects is often impaired by radiotherapy since bone quality is compromised by radiation. This study aims to investigate the therapeutic efficacy of the composite cell sheets-bone marrow mesenchymal stem cell (BMSC) sheets cocultured with endothelial progenitor cells (EPCs)-in the healing of irradiated bone defects and the biological effects of EPCs on the osteogenic properties of BMSC sheets. Methods BMSCs and EPCs were isolated from rat bone marrow. BMSCs were used to form cell sheets by the vitamin C inducing method. EPCs were seeded on BMSC sheets to make EPCs–BMSC sheets. Osteogenesis of EPCs–BMSC sheets and BMSC sheets were tested. In vitro osteogenesis tests included ALP, Alizarin Red S, Sirius Red staining, qRT-PCR and Western blot analysis after 3 and 7 days of osteogenic incubation. Subcutaneous osteogenesis was tested by H&E staining and immunohistochemical staining 8 weeks after transplantation. EPCs–BMSC sheets and BMSC sheets were used in the 3 mm defects of non-irradiated and irradiated rat tibias. Micro-CT and histological analysis were used to test the healing of bone defects 4 and 8 weeks after transplantation. Results EPCs–BMSC sheets showed enhanced osteogenic differentiation in vitro with increased expression of osteoblastic markers and osteogenesis related staining compared with BMSC sheets. In subcutaneous osteogenesis test, EPCs–BMSC sheets formed larger areas of new bone and blood vessels. The EPCs–BMSC group had the highest volume of newly formed bone in the defect area of irradiated tibias. Conclusions EPCs improved the osteogenic differentiation of BMSC Sheets and enhanced the ectopic bone formation. EPCs–BMSC sheets promoted bone healing in irradiated rat tibias. EPCs–BMSC sheets are potentially useful in the reconstruction of bone defect after radiotherapy. Electronic supplementary material The online version of this article (10.1186/s12967-018-1517-4) contains supplementary material, which is available to authorized users.

Additional file 3: Table S1. BV/TV (%) of the micro-CT evaluation. Table S2. p value of comparison of BV/TV. Table S3. Area of fluorochromes stained bone (%). Table S4. p value of comparison of fluorochromes stained area.

Condyle fractures are common in children and are increasingly treated with open reduction. Three-dimensional printing has developed into an important method of assisting surgical treatment. This report describes the case of a 14-year-old patient treated for a right condyle fracture at the authors' hospital. Preoperatively, the authors designed a surgical guide using 3-dimensional printing and virtual surgery. The 3-dimensional surgical guide allowed accurate alignment of the fracture using Kirschner wire without additional dissection and tissue injury. Kirschner wire fixation augmented by 3-dimensional printing technology produced a good outcome in this adolescent condyle fracture.

Bacterial invasion and epithelial downgrowth with pocket formation are still severe clinical challenges for transcutaneous implants, and both have a close relationship with the lack of a stable biological seal around the transcutaneous parts. Dermal fibroblasts are the main cells in the skin tissue and have been proven to play vital roles in the formation of biological seals. In this work, platelet-rich plasma (PRP), which can release high concentrations of natural cytokines upon activation, was used to stimulate rapid fibroblast growth. Mussel adhesive proteins (MAPs) were used as mediators to anchor the platelets in the PRP onto Ti surfaces, and MAP/PRP composite-coated Ti surfaces were constructed successfully. This in vitro study indicated increased fibroblast adhesion (P < 0.05), spreading, and proliferation (P < 0.05) and upregulated extracellular matrix-related gene expression (P < 0.05) on a MAP/PRP composite-coated Ti surface compared with a control smooth Ti surface. Our results suggest that MAP/PRP composite-coated Ti surfaces are potentially useful for the formation of a stable biological seal in transcutaneous areas.

Periodontal disease is considered as a widespread infectious disease and the most common cause of tooth loss in adults. Attempts for developing periodontal disease treatment strategies, including drug delivery and regeneration approaches, provide a useful experimental model for the evaluation of future periodontal therapies. Recently, emerging advanced biomaterials including hydrogels, films, micro/nanofibers and particles, hold great potential to be utilized as cell/drug carriers for local drug delivery and biomimetic scaffolds for future regeneration therapies. In this review, first, we describe the pathogenesis of periodontal disease, including plaque formation, immune response and inflammatory reactions caused by bacteria. Second, periodontal therapy and an overview of current biomaterials in periodontal regenerative medicine have been discussed. Third, the roles of state-of-the-art biomaterials, including hydrogels, films, micro/nanofibers and micro/nanoparticles, developed for periodontal disease treatment and periodontal tissue regeneration, and their fabrication methods, have been presented. Finally, biological properties, including biocompatibility, biodegradability and immunogenicity of the biomaterials, together with their current applications strategies are given. Conclusive remarks and future perspectives for such advanced biomaterials are discussed.

BACKGROUND There were many articles about double-barreled fibular flap for mandibular reconstruction. The upper layer bone was suit for implant placement as a new alveolar. The lower layer was necessary for contour. But the accurate relationship between the 2 layers bone was rarely reported. OBJECTIVES The purpose of this study was twofold: to evaluate the feasibility of the novel design of the double-barreled fibular flap from virtual surgery to actual result; to evaluate the accuracy and results of occlusion-guided double-barreled fibular free flap in mandible reconstruction. METHODS From 2010 to 2016, 52 patients underwent segmental mandibular reconstruction with double-barreled fibular osteoseptocutaneous flaps with computer aided design/computer aided manufacturing technique. Preoperative computer tomographic (CT) scans were imported into Mimics 10.01 software (Materialise, Leuven, Belgium) for surgical planning. The peroneal vessel pedicel was designed at the lower barrel segmental bone of the double-barreled fibular flap. The double-barreled bone was strung with 16 mm fixation screws instead of mini-plate. Sixty-three dental implants placement was simultaneous in 30 patients and 32 dental implants placement was in second stage in 18 patients. Postoperative CT and digital imaging were evaluated to assess surgical accuracy using software. The pre- and postoperative morphometric measurements were compared using the Fisher exact t test. RESULTS Two flaps occurred vascular crisis postoperatively. There was no flap necrosis. Four implants failed during 1 to 5 weeks postoperative. Sixty-six CT scans from 33 patients who underwent partial mandibular resection were analyzed. The dimensions of the double-barreled fibula segments after osteotomy showed no difference from the preoperative virtual surgical planning (VSP). But the condylar locations showed a disposition out of the fossa (P

Irradiated bone has a greater risk of implant failure than nonirradiated bone. The purpose of this study was to investigate the influence of cell sheets composed of co-cultured bone marrow mesenchymal stromal cells (BMSCs) and endothelial progenitor cells (EPCs) on implant osseointegration in irradiated bone. Cell sheets (EPCs, BMSCs or co-cultured EPCs and BMSCs) were wrapped around titanium implants to make cell sheet-implant complexes. The co-cultured group showed the highest osteogenic differentiation potential in vitro, as indicated by the extracellular matrix mineralization and the expression of osteogenesis related genes at both mRNA and protein levels. The co-cultured cells promoted ectopic bone formation as indicated by micro-computed tomography (Micro-CT) and histological analysis. In the irradiated tibias of rats, implants of the co-cultured group showed enhanced osseointegration by Micro-CT evaluation and histological observation. Co-cultured EPCs and BMSCs also up-regulated the expression of osteogenesis related genes in bone fragments in close contact with implants. In conclusion, cell sheets of co-cultured EPCs and BMSCs could promote osseous healing around implants and are potentially useful to improve osseointegration process for patients after radiotherapy.

Fibroblasts, which play an important role in biological seal formation and maintenance, determine the long-term success of percutaneous implants. In this study, well-defined microporous structures with micropore diameters of 10–60 µm were fabricated by microelectromechanical systems and their influence on the fibroblast functionalities was observed. The results show that the microporous structures with micropore diameters of 10–60 µm did not influence the initial adherent fibroblast number, however, those with diameters of 40 and 50 µm improved the spread, actin stress fiber organization, proliferation and fibronectin secretion of the fibroblasts. The microporous structures with micropore diameters of 40–50 µm may be promising for application in the percutaneous part of an implant.

Objectives In order to get predictable reassembling and higher accuracy in the reconstruction of the mandible, we designed three kinds of fibula cutting guides: (1) Two-edge wide groove guide (WGG); (2) Two-edge narrow groove guide (NGG); and (3) One-edge guide (OEG). The purpose of this study was to compare the accuracy of fibula remodelling using the three kinds of fibula cutting guides above in a simulation procedure in vitro. Materials and methods Cutting and reshaping of fibula analogs were guided by the three kinds of guides mentioned above. Then the fibula segments were glued together and scanned with CT, and finally the 3D accuracy of fibula reshaping was compared to the virtual plan. Results Comparisons were made with regard to planned versus actual fibula segment length and angle projections in 3 planes. There were no significant differences in length change among the WGG group, NGG group and OEG group. There were very significant differences in angle projections in 3 planes between every 2 of the 3 groups. Conclusions 3 kinds of guides do not affect the length of fibula segments. Two-edge narrow groove guides (NGG) caused the smallest error among the 3 kinds of guides. The error caused by two-edge wide groove guide (WGG) was similar to that caused by one-edge guide (OEG). The conclusion was in consistent with the referred groove-restriction-effect in the section of discussion. Clinical relevance We suggest that the two-edge narrow groove guide (NGG) is the superior choice for fibula cutting in reconstruction of the mandible.

Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration.

Purpose The aims of this study are to introduce a novel method of 3-dimensional (3D) analysis of the face and to provide normative data of the Chinese face for surgeons. Materials and Methods Fifty men and 50 women were recruited, and a 3D stereophotogrammetry system was used to acquire their facial image data. For each subject, the image was aligned to a unified coordinate system, and coordinate values of 31 facial landmarks were collected. Mean values for each landmark were calculated within genders, and 3D models of both genders were constructed based on the mean values. Subsequently, to evaluate the sexual dimorphism, the models were superimposed. Then, to delineate the shape differences independent of size, the models were normalized and superimposed again. The application of the 3D models was also exemplified by analysis of a subject's facial deformity. Results Linear and polyhedron 3D models representing the facial shape were built for both genders. The superimposed models and the absolute differences between each landmark in both genders illustrated the sexual dimorphism of the Chinese face, and the normalized models and relative difference for each landmark also delineated the shape differences independent of size. In addition, a subject's facial deformity was evaluated by referring to the normative 3D facial models. Conclusions This study describes a new 3D analysis method for facial morphology. Three-dimensional models representing the facial shape of Chinese subjects were built, and sexual dimorphism was investigated. These would provide useful guidance for facial anthropometry and plastic surgeons in clinical practice.

Frontal photographs of the head in its natural position are not as easy to achieve as lateral ones. We describe a new way to obtain standard 2-dimensional images of its natural position in full-face frontal view using a customised photographic system, which may provide supplementary information for traditional lateral facial imaging, and be helpful for standard assessment of 3-dimensional facial images.

We describe a technique for the design and fabrication of realistic facial prostheses using three-dimensional optical imaging and computer-aided design and manufacturing (CAD/CAM). A three-dimensional dataset of the facial surface of a patient who needed a facial prosthesis was obtained using a sensing system, and the three-dimensional image of the face was reconstructed. A decreased and thinned virtual prosthesis was designed based on the facial image and converted into a rapid prototyping wax prosthesis using a selective laser sintering technique. The rapid prototyping wax prosthesis was then dipped into melted base-plate wax which generated a layer of wax on the internal and external surfaces to record its size and thickness. The modified prosthesis was evaluated and refined, and processed to generate a realistic silicone prosthesis. Three-dimensional data acquisition using the sensing system and computer-assisted design and manufacture of the prosthesis allows us to see a whole face without damaging the soft tissues or causing discomfort to the patient or exposure to radiation. The final prosthesis was of satisfactory size, shape, and cosmetic appearance, matched the malformed area, and suited the patient's requirements.

Summary: The loss of midface structures always leads to significant functional and cosmetic deficits, and the reconstruction work remains a challenge for surgeons. We report a rare case with severe midfacial defects involving the maxilla, nasal bone, and zygoma. This patient was treated with a comprehensive approach that included distraction osteogenesis, computer-aided surgery, a fibula bone graft, dental implantation, orthognathic surgery, and rhinoplasty. The treatment procedures required 4 years to complete, and a dramatically improved facial contour and stable occlusion were achieved. The results demonstrated the importance of a multidisciplinary approach and computer-aided design when treating severe maxillofacial deformities. Other important elements of the treatment process were the meticulous physical examination, the selection of an optimal treatment sequence, the skill of the surgeons, and more importantly, the patient-oriented mindset.

Statement of problem The passive film on the surface of titanium can be destroyed by immersion in a fluoridated acidic medium. Coating with titanium nitride (TiN) may improve the corrosion resistance of titanium. Purpose The purpose of this in vitro study was to investigate the effect of duplex treatment with plasma nitriding and TiN coating on the corrosion resistance of cast titanium. Material and methods Cast titanium was treated with plasma nitriding and TiN coating. The corrosion resistance of the duplex-treated titanium in fluoride-containing artificial saliva was then investigated through electrochemical and immersion tests. The corroded surface was characterized by scanning electron microscopy (SEM) with energy-dispersive spectroscopy surface scan analysis. The data were analyzed using ANOVA (α=.05) Results Duplex treatment generated a dense and uniform TiN film with a thickness of 4.5 μm. Compared with untreated titanium, the duplex-treated titanium displayed higher corrosion potential (E corr ) values ( P .001) and lower corrosion current density (I corr ) values ( P .001). SEM results showed that the surface of untreated titanium was more heavily corroded than that of duplex-treated titanium. Surface scan analysis of duplex-treated titanium that had been immersed in artificial saliva containing 2 g/L fluoride revealed fluorine on the titanium surface, whereas fluorine was not observed on the surface of untreated titanium after immersion in fluoride-containing artificial saliva. The concentration of titanium ions released from the treated titanium was less than the amount released from untreated titanium ( P .001). Conclusions Duplex treatment by plasma nitriding and TiN coating significantly improved the corrosion resistance of cast titanium in a fluoride-containing environment.

Background The application of a maxillofacial prosthesis is an alternative to surgery in functional–aesthetic facial reconstruction. Computer aided design/computer aided manufacturing has opened up a new approach to the fabrication of maxillofacial prostheses. An intelligentized rapid simulative design and manufacturing system for prostheses was developed to facilitate the prosthesis fabrication procedure. Methods The rapid simulation design and rapid fabrication system for maxillofacial prostheses consists of three components: digital impression, intelligentized prosthesis design, and rapid manufacturing. The patients’ maxillofacial digital impressions were taken with a structured-light 3D scanner; then, the 3D model of the prostheses and their negative molds could be designed with specific software; lastly, with resin molds fabricated by the rapid prototyping machine, the prostheses could be produced directly and quickly. Results Fifteen patients with maxillofacial defects received prosthesis rehabilitation provided by the established system. The total clinical time used for each patient was only 4 hours over 2 appointments on average. The contours of the prostheses coordinated properly with the appearance of the patients, and the uniform-thickness border sealed well to adjacent tissues. All of the patients were satisfied with their prostheses. Conclusions The rapid simulative rehabilitation system of maxillofacial defects is approaching completion. It could provide an advanced technological solution for the Army in cases of maxillofacial defect rehabilitation.

The challenge of fabricating an orbital prosthesis is how to position the iris and pupil properly. Computer simulation can be a more effective and simpler approach to measuring and evaluating these features than the conventional method. However, transferring the optimal position of the iris determined in the virtual design procedure to the real definitive prosthesis can be difficult. The purpose of this article is to demonstrate a method of fabricating an orbital prosthesis with a negative mold designed and produced by a computer-aided design and computer-aided manufacturing technique. With this method, the iris can be designed in the most favorable position, and this position can be transferred to the silicone prosthesis correctly.

Hongbo Wei*, Shuyi Wu*, Zhihong Feng, Wei Zhou, Yan Dong, Guofeng Wu, Shizhu Bai, Yimin Zhao Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China *These authors contributed equally to this workAbstract: Infection and epithelial downgrowth are major problems associated with maxillofacial percutaneous implants. These complications are mainly due to the improper closure of the implant–skin interface. Therefore, designing a percutaneous implant that better promotes the formation of a stable soft tissue biologic seal around percutaneous sites is highly desirable. Additionally, the fibroblast has been proven to play an important role in the formation of biologic seals. In this study, titania nanotubes were filled with 11.2 kDa C-terminal CCN2 (connective tissue growth factor) fragment, which could exert full CCN2 activity to increase the biological functionality of fibroblasts. This drug delivery system was fabricated on a titanium implant surface. CCN2 was loaded into anodized titania nanotubes using a simplified lyophilization method and the loading efficiency was approximately 80%. Then, the release kinetics of CCN2 from these nanotubes was investigated. Furthermore, the influence of CCN2-loaded titania nanotubes on fibroblast functionality was examined. The results revealed increased fibroblast adhesion at 0.25, 0.5, 1, 2, 4, and 24 hours, increased fibroblast viability over the course of 5 days, as well as enhanced actin cytoskeleton organization on CCN2-loaded titania nanotubes surfaces compared to uncoated, unmodified counterparts. Therefore, the results from this in vitro study demonstrate that CCN2-loaded titania nanotubes have the ability to increase fibroblast functionality and should be further studied as a method of promoting the formation of a stable soft tissue biologic seal around percutaneous sites.Keywords: anodization, titania nanotubes, adhesion, connective tissue growth factor, fibroblast

The bone-anchored implant-retained craniofacial prosthesis system is a viable alternative to conventional reconstructive surgery and offers significant improvement in the quality of life when compared with the support systems previously available for these types of prostheses. Ideal placement of bone-integrated implants to retain the prosthesis is critical for a successful final prosthetic restoration. The implant abutments and retentive elements should be hidden under the prosthesis and will not interfere with the esthetic contours of the final result. Several sources have described the imporance and use of surgical templates for the optimal lacement of extraoral implants. Marking the proposed location for the implants with a dye through holes in an acrylic ear is the general method, but it does not provide a full guide for the implants’ insertion. The purpose of this article is to describe a novel method to design and fabricate the implant guide for an auricular prosthesis; this method enables implants to be placed in predetermined positions with flapless surgery.