Fluorine-Containing Covalent Organic Frameworks: Synthesis and Application.

Covalent organic frameworks (COFs) are a type of crystalline porous polymers that possess ordered structures and eternal pores. Because of their unique structural characteristics and diverse functional groups, COFs have been used in various application fields, such as adsorption, catalysis, separation, ion conduction, and energy storage. Among COFs, the fluorine-containing COFs (fCOFs) have been developed for special applications by virtue of special physical and chemical properties resulting from fluorine element, which is a nonmetallic halogen element and possesses strong electronegativity. In the organic chemistry field, introducing fluorine into chemicals enables those chemicals to exhibit many interesting properties, and fluorine chemistry increasingly plays an important role in the history of chemical development. The introduction of fluorine in COFs can enhance the crystallinity, porosity, and stability of COFs, making COFs having superior performances and some new applications. In this review, the synthesis and application of fCOFs are systematically summarized. The application involves photocatalytic production of hydrogen peroxide, photocatalytic water splitting, electrocatalytic CO2 reduction, adsorption for different substances (H2 , pesticides, per-/polyfluoroalkyl substances, polybrominated diphenyl ethers, bisphenols, and positively charged organic dye molecules), oil-water separation, energy storage (e.g., zinc-ion batteries, lithium-sulfur batteries), and proton conduction. Perspectives of remaining challenges and possible directions for fCOFs are also discussed.

Symmetrical Midfacial Growth After Pediatric Mandibular Reconstruction With Free Fibula Flap.

BACKGROUND: Free fibula is the workhorse flap for mandibular reconstruction and is increasingly being used in pediatric patients. However, craniomaxillofacial growth and development involve interdependent processes, and it remains unknown whether mandibular reconstruction with free fibula allows symmetric growth of the midface. PURPOSE: The study evaluated midfacial symmetry after pediatric mandibular defect reconstruction. STUDY DESIGN, SETTING, SAMPLE: This retrospective cohort study included pediatric patients aged ≤14 years who underwent mandibular reconstruction with free fibula flap. Postoperative computed tomography data were obtained at predefined follow-up time points. Midfacial symmetry was evaluated based on 3-dimensional (3D) cephalometry. PREDICTOR VARIABLE: The predictor variable was the side of the midface (affected or healthy side relative to the mandibular defect). MAIN OUTCOME VARIABLES: The primary outcome variable was postoperative midfacial symmetry (at 1 week, 6 months, 1 year, 2 years, and >3 years, or after the age of 18 years), assessed in horizontal, vertical, and anteroposterior dimensions using 3D cephalometry. Another outcome variable was patient satisfaction based on a self-evaluation using visual analog scoring. COVARIATES: Sex, age, diagnosis, and type of denture restoration. ANALYSES: Paired t tests were performed to assess the relationship between the predictor and outcome variables, with the significance level of P < .05. RESULTS: A total of 13 patients were included in this study (9 males and 4 females; mean age: 12.23 ± 2.39 years). The average distance from upper first molar point (U6) to the horizontal plane on the affected side became greater than on the healthy side (difference: 0.7 ± 0.5 mm to 1.6 ± 1.4 mm, P < .05), while the average distance from pterygomaxillary fissure to coronal plane on affected side became shorter than that on the healthy side (difference: 0.6 ± 0.6 mm to 1.2 ± 1.1 mm, P < .05) from 1 year after the surgery. There were no statistically significant differences in the remaining measurements between the 2 sides (P > .05). All the patients were satisfied with their postoperative facial symmetry. CONCLUSIONS AND RELEVANCE: There were no severe midface deformities after pediatric mandibular reconstruction with free fibula flap. Meanwhile, pediatric mandibular reconstruction and proper occlusion could promote midfacial growth and symmetry.

Transition in plant-plant facilitation in response to soil water and phosphorus availability in a legume-cereal intercropping system.

BACKGROUND: The tradeoff between negative and positive interactions of facilitated species and facilitators may depend on the degree of resource availability in agroecosystems. However, the rhizospheric mechanisms driving trade-offs that occur along phosphorus (P) and water availability gradients have not yet been systematically clarified. We established three types of root isolation conditions (no barrier, nylon barrier and solid barrier) at different P and water addition levels to address the above issue in a maize-grass pea intercropping system. RESULTS: The total yield and biomass net effect (NE) and the relative interaction index (RII) were significantly higher than 0 under all environmental conditions, demonstrating that plant-plant interactions generated positive effects in the intercropping system. The maize yield and biomass RII were 0.029-0.095 and 0.018-0.066, respectively, which indicated that maize growth was constantly facilitated. However, the RII for grass pea yield and biomass exhibited a different trend in comparison with maize. It was higher than 0 (as the facilitated species) under low soil P and moisture conditions and transitioned to values lower than 0 (facilitator species) under high P and moisture conditions, which showed that the type and intensity of plant-plant interactions steadily shifted with the applied stressors. Direct interactions decreased the maize rhizospheric soil pH by 1.5% and 1.9% under Low-P conditions. Notably, the rhizospheric soil acid and alkaline phosphatase secretions of maize and grass pea increased by 17.4-27.4% and 15.3-27.7%, respectively, in P-deficient soils. These results show that plant-plant interactions can effectively relieve P stress by mineralizing organophosphorus in P-deficient soils. Furthermore, the above tendency became more pronounced under drought-stressed conditions. The nylon barrier partially restricted the exchange and utilization of available nutrients and decreased the total yield and biomass by 1.8-7.8% and 1.1-7.8%, respectively. The presence of a solid barrier completely restricted interspecific rhizospheric interactions and decreased the total yield and biomass by 2.1-13.8% and 1.6-15.7%, respectively. Phytate and KH2PO4 addition intensified asymmetric interspecific competition, and grass pea was consistently subjected to competitive pressures. CONCLUSION: Briefly, the tradeoff between facilitation and competition was driven by rhizospheric interactions, and the transition in the intensity and type of interaction was highly dependent on resource availability in a biologically diverse system.

Vertebroplasty combined with facet joint block vs. vertebroplasty alone in relieving acute pain of osteoporotic vertebral compression fracture: a randomized controlled clinical trial.

OBJECTIVE: The study objective was to compare the efficacy and safety of percutaneous vertebroplasty (PVP) combined with facet joint block (FB) and vertebroplasty alone in relieving acute pain on osteoporotic vertebral compression fractures (OVCFs). METHODS: A prospective, randomized controlled study was conducted. One hundred ninety-eight patients of OVCFs undergoing surgery were randomly divided into two groups: Group P (PVP, n = 97), Group PF (PVP + FB, n = 101). The Visual analogue scale (VAS) and Oswestry disability index (ODI) were measured during pre-operation, 1 day, 1, 3, 6 and 12 months after the operation, respectively. The hospitalization time, operation time, complications, recurrence, the mean amount of cement injected and the number of patients who applied Cox-2 inhibitors within 3 days after operation were compared in the two groups. RESULTS: The VAS and ODI scores at each observation point of the post-operation were significantly decreased than that at the pre-operation in both groups (P < 0.05). The VAS and ODI scores in Group PF were significantly lower than that in Group P 1 day and 1 month after the operation (P < 0.05). The number of patients who applied Cox-2 inhibitors within 3 days after operation in group PF was significantly lower that in Group P (P < 0.001). There was no significant difference in hospitalization time, operation time, the mean amount of cement injected, complication rate, VAS and ODI scores at the pre-operation (P > 0.05). CONCLUSION: Both PVP combined with FB and PVP alone are effective treatment methods for OVCFs. But PVP combined with FB showed better back pain relief than PVP alone in the short term after the operation for OVCFs.

Reconstruction of Complete Bilateral Maxillary Defects With Free Flaps.

ABSTRACT: Reconstruction of complete bilateral maxillary defects (CBMDs) can be challenging due to the extensive loss of bone and soft tissues. This is a retrospective case series of 46 consecutive patients with CBMDs that were reconstructed with different micro-vascular free flaps. The authors aimed to evaluate the surgical outcomes and discuss the different reconstruction options in this case series. Thirty-six patients underwent reconstruction following ablation surgery for malignant tumors, 6 for benign tumors, 3 patients were treated for osteomyelitis, and 1 patient underwent free flap reconstruction for posttraumatic defects. Free fibula flap (n = 26) is the most commonly used reconstruction method in this case series, which was used in all defect types. This is followed by anterolateral thigh flap (n = 10), 5 rectus abdominis myocutaneous free flap, 3 radial forearm free flaps, and 2 composite free flaps. In this series, 44 free flaps survived, whereas only 2 flaps were lost. All patients could resume a soft diet postoperatively. Reconstruction of CBMDs with vascularized free flaps is a safe and reliable procedure.

Degradation of tetracycline wastewater by suspended biochar as carriers in moving bed biofilm reactor.

To improve the removal efficiency of antibiotics in moving bed biofilm reactor, suspended biochar block was prepared by the one-pot process and was used as carriers to construct a reaction device to study the treatment effect of antibiotic wastewater. The characteristics of the hanging biofilm in wastewater were investigated. And the mechanism of biochar as a biological carrier has been studied. The results showed that in the 45-day experiment, the maximum number of biofilms for suspended biochar carriers was twice 3.4 times that of the high-density polyethylene carriers. When 10 mg/L tetracycline was added to the reactor, the removal efficiency of the tetracycline removal rate was 71.85% and the chemical oxygen demand (COD), total nitrogen (TN), and NH4+-N removal efficiency reached to 89.95, 61.91 and 85.47% respectively. Suspension biochar carriers can reduce fluctuations in redox potentials, thereby improving the cellular efficiency of microorganisms. Meanwhile, it inhibits the production of soluble microbial products and extracellular polymers, reduces toxic effects, and enhances the adhesion between microorganisms and carriers. The microbial communities of the two carriers were investigated by high-throughput sequencing techniques. Suspended biochar significantly increased the relative abundance of Hydrogenophaga and Comamonas, and improved the ability of nitrification and denitrification. Comamonas could be responsible for tetracycline degradation.

Factors influencing the accuracy of multimodal image fusion for oral and maxillofacial tumors: a retrospective study.

BACKGROUND: Ensuring high accuracy in multimodal image fusion for oral and maxillofacial tumors is crucial before further application. The aim of this study was to explore the factors influencing the accuracy of multimodal image fusion for oral and maxillofacial tumors. METHODS: Pairs of single-modality images were obtained from oral and maxillofacial tumor patients, and were fused using a proprietary navigation system by using three algorithms (automatic fusion, manual fusion, and registration point-based fusion). Fusion accuracy was evaluated including two aspects-overall fusion accuracy and tumor volume fusion accuracy-and were indicated by mean deviation and fusion index, respectively. Image modality, fusion algorithm, and other characteristics of multimodal images that may have potential influence on fusion accuracy were recorded. Univariate and multivariate analysis were used to identify relevant affecting factors. RESULTS: Ninety-three multimodal images were generated by fusing 31 pairs of single-modality images. The interaction effect of image modality and fusion algorithm (P = 0.02, P = 0.003) and thinner slice thickness (P = 0.006) were shown to significantly influence the overall fusion accuracy. The tumor volume (P < 0.001), tumor location (P = 0.007), and image modality (P = 0.01) were significant influencing factors for tumor volume fusion accuracy. CONCLUSIONS: To ensure high overall fusion accuracy, manual fusion was not preferred in CT/MRI image fusion, and neither was automatic fusion in image fusion containing PET modality. Using image sets with thinner slice thickness could increase overall fusion accuracy. CT/MRI fusion yielded higher tumor volume fusion accuracy than fusion containing PET modality. The tumor volume fusion accuracy should be taken into consideration during image fusion when the tumor volume is small and the tumor is located in the mandible.

Double-Barrel Fibula Flap Versus Vascularized Iliac Crest Flap for Mandibular Reconstruction.

PURPOSE: The double-barrel fibula flap and vascularized iliac crest flap are both commonly used for mandibular reconstruction. The present study compared the usage and reconstruction outcomes of transplanted bone with these 2 methods. PATIENTS AND METHODS: The data from 30 patients who had undergone mandibular osteotomy and reconstruction were retrospectively reviewed. Of the 30 patients, 20 received a vascularized iliac crest flap (group A) and 10 received a double-barrel fibula flap (group B). The following variables were compared between the 2 groups: volume of bone flap (VBF), volume of effective bone flap (VEBF; ie, overlap between the volume of the ideal mandible [VIM] and the VBF), usage of the bone flap (VEBF divided by the VBF), mandibular reconstruction rate (VEBF divided by the VIM), volume of needless bone flap (VNBF; ie, VBF minus VEBF; the VNBF included the volume of needless buccal bone flap [VNBBF] and the volume of needless lingual bone flap [VNLBF]), percentage of alveolar crest restoration (PACR; ie, effective bone flap width divided by ideal alveolar crest width), and height of the bone flap (HBF). The independent-samples t test and the χ2 test were used to compare the variables between the 2 groups. Statistical significance was at P ≤ .05. RESULTS: Usage of the bone flap and the length of the mandibular defect were significantly greater in group B than in group A (P = .039 and P < .001, respectively). The VBF, VNBF, and VNLBF were significantly greater in group A than in group B (P < .001 for both). The mandibular reconstruction rate, VNBBF, PACR, HBF, and tooth implantation rate were comparable between the 2 groups. CONCLUSIONS: The double-barrel fibula flap can effectively restore the height of the alveolar crest, reconstruct longer mandibular defects, and provide a better buccal and lingual appearance compared with the vascularized iliac crest flap. Although the vascularized iliac crest flap can provide sufficient bone quantity, it must be contoured to the mandible.

Regeneration of the Neocondyle After Free Fibular Flap Reconstruction of the Mandibular Condyle.

PURPOSE: Shifting of the flap position after condylar reconstruction with free fibular flaps is known to occur, but its long-term effects on postoperative esthetic outcomes have not been sufficiently reported. Therefore, in this study, we evaluated the long-term morphologic stability of the free fibular flap neocondyle. PATIENTS AND METHODS: This was a retrospective cohort study. The primary outcome variables were neocondyle regeneration and neocondyle position including the distance between the glenoid fossa and the initial neocondyle (Fo-Co), the distance between the glenoid fossa and the stable neocondyle (Fo-Co'), and shifting of the neocondyle (defined as the distance between the stable neocondyle and the initial neocondyle). The primary predictor variable was time. The other variables were age, gender, diagnosis, and number of fibular segments. Correlation analysis between the predictor variables and outcome variables was performed. RESULTS: The sample was composed of 26 patients (11 male and 15 female patients) with a mean age of 31 years. Diagnosis and number of fibular segments were significantly associated with Fo-Co and Fo-Co' (P < .05). Among the 26 patients, only 11 showed neocondyle regeneration at follow-up (group A) whereas 15 did not (group B). Neocondyle regeneration was significantly associated with patient age (P < .01). Stable Fo-Co and stable time were significantly associated with neocondyle regeneration (P < .05). The mean stable time was significantly shorter in group A (3.64 ± 1.12 months) than in group B (6.67 ± 3.85 months) (P < .05), and the mean Fo-Co' was significantly shorter in group A (13.65 ± 3.94 mm) than in group B (20.68 ± 8.87 mm) (P < .05). CONCLUSIONS: The possibility of neocondyle regeneration is higher in pediatric patients than in adults. Neocondyle regeneration could result in the movement of the neocondyle toward the glenoid fossa with a shorter stable time, which could improve neocondyle repositioning. Repositioning of the neocondyle with free fibular flaps for mandibular condyle defects is a self-adaption process for temporomandibular joint function.

Selection of Guiding Plate Combined With Surgical Navigation for Microsurgical Mandibular Reconstruction.

PURPOSE: The present study summarized selection of guiding plate combined with surgical navigation for microsurgical mandibular reconstruction. METHODS: Data from preoperative maxillofacial enhanced computed tomography (CT) scans were imported to ProPlan CMF. The authors performed virtual mandibulectomy and superimposed 3-dimensional (3D) iliac images on mandibular defects. Guiding plates including mandibular fixation device, reconstruction plate, guiding model, and occlusal splint for various mandibular hemimandibular central lateral (HCL) defects were fabricated to fix bilateral residual mandible. The model was scanned, and data were imported into ProPlan CMF and the intraoperative navigation system. Through landmark points upon the guiding plate, position of the residual mandible was determined during surgical navigation. Intraoperative navigation was used to implement the virtual plan. Sagittal, coronal, axial, and 3D reconstruction images displayed by the navigation system were used to accurately determine osteotomy sites and osteotomy trajectory during surgery. Surgical probe guidance was used to mark the osteotomy line and transfer the virtual procedure to real-time surgery. Accuracy was evaluated using chromatographic analysis. RESULTS: Different guiding plates combined with surgical navigation could be used for various mandibular defects, including mandibular fixation devices for LCL defects, reconstruction plates for LC/L/C defects, and guiding models and occlusal splints for H/L/LC defects (including mandibular ramus). In our study, average and largest shift of the mandible and osteotomy site was <5 mm. CONCLUSION: The authors summarized different ways of combining guiding plates with surgical navigation for reconstruction of various mandibular defects, which could improve clinical outcomes of this procedure with high accuracy.

Molecular surveillance of coxsackievirus A16 reveals the emergence of a new clade in mainland China.

Coxsackievirus A16 (CV-A16) of the genotypes B1a and B1b have co-circulated in mainland China in the past decades. From 2013 to 2017, a total of 3,008 specimens from 3,008 patients with mild hand, foot, and mouth disease were collected in the present study. Viral RNA was tested for CV-A16 by a real-time RT-PCR method, and complete VP1 sequences and full-length genome sequences of CV-A16 strains from this study were determined by RT-PCR and sequencing. Sequences were analyzed using a series of bioinformatics programs. The detection rate for CV-A16 was 4.1%, 25.9%, 10.6%, 28.1% and 12.9% in 2013, 2014, 2015, 2016 and 2017, respectively. Overall, the detection rate for CV-A16 was 16.5% (497/3008) in this 5-year period in Shenzhen, China. One hundred forty-two (142/155, 91.6%) of the 155 genotype B1 strains in the study belonged to subgenotype B1b, and 13 (13/155, 8.4%) strains belonged to subgenotype B1a. Two strains (CVA16/Shenzhen174/CHN/2017 and CVA16/Shenzhen189/CHN/2017) could not be assigned to a known genotype. Phylogenetic analysis of these two strains and other Chinese CV-A16 strains indicated that these two CV-A16 strains clustered independently in a novel clade whose members differed by 8.4%-11.8%, 8.4%-12.1%, and 14.6%-14.8% in their nucleotide sequences from those of Chinese B1a, B1b, and genotype D strains, respectively. Phylogenetic analysis of global CV-A16 strains further indicated that the two novel CV-A16 strains from this study grouped in a previously uncharacterized clade, which was designated as the subgenogroup B3 in present study. Meanwhile, phylogenetic reconstruction revealed two other new genotypes, B1d and B4, which included a Malaysian strain and two American strains, respectively. The complete genome sequences of the two novel CV-A16 strains showed the highest nucleotide sequence identity of 92.3% to the Malaysian strain PM-15765-00 from 2000. Comparative analysis of amino acid sequences of the two novel CV-A16 strains and their relatives suggested that variations in the nonstructural proteins may play an important role in the evolution of modern CV-A16.

Outcomes of Zygomatic Complex Reconstruction With Patient-Specific Titanium Mesh Using Computer-Assisted Techniques.

PURPOSE: Zygomatic complex defects after extensive maxillectomy can cause severe esthetic and functional deformities. Patient-specific titanium mesh fabricated using a computer-assisted technique is a promising method for such midface reconstruction. The aim of this study was to evaluate the application and clinical outcomes of this technique. PATIENTS AND METHODS: This was a retrospective study that included 9 patients with zygomatic complex defects after extensive maxillectomy from 2015 through 2017 at the authors' institution. A 3-dimensional stereo model was obtained based on mirror images of the unaffected side to fabricate a patient-specific titanium mesh using computer-assisted design and manufacturing. Titanium mesh was used to restore the contour of the zygomatic complex with free flap reconstruction after tumor resection. Anterolateral thigh flaps were used in 8 cases and a myocutaneous fibula flap was used in 1 case. Symmetry of the zygomatic complex was evaluated by measuring the zygomatic eminence on the postoperative computed tomogram, and complications were recorded during follow-up visits. Facial symmetry was self-evaluated and scored. RESULTS: Mean duration for follow-up was 27.3 months (range, 15 to 39 months). Mean deviation of the zygomatic eminence between the reconstructed and unaffected sides was 1.4 ± 0.5 mm. No significant difference was noted in the zygomatic eminence between the reconstructed and unaffected sides (P = .591). Titanium mesh exposure occurred in only 1 patient after radiotherapy. There were no other remarkable complications. All patients were satisfied with their postoperative facial symmetry. CONCLUSION: Patient-specific titanium mesh fabricated using a computer-assisted technique was an alternative option for extensive zygomatic complex reconstruction, resulting in acceptable clinical outcomes. A study with a larger sample and long-term follow-up is needed for the observation of long-term outcomes and risk of titanium mesh-related complications.

A Microfluidic Strategy for Controllable Generation of Water-in-Water Droplets as Biocompatible Microcarriers.

Droplet microfluidics has been widely applied in functional microparticles fabricating, tissue engineering, and drug screening due to its high throughput and great controllability. However, most of the current droplet microfluidics are dependent on water-in-oil (W/O) systems, which involve organic reagents, thus limiting their broader biological applications. In this work, a new microfluidic strategy is described for controllable and high-throughput generation of monodispersed water-in-water (W/W) droplets. Solutions of polyethylene glycol and dextran are used as continuous and dispersed phases, respectively, without any organic reagents or surfactants. The size of W/W droplets can be precisely adjusted by changing the flow rate of dispersed and continuous phases and the valve switch cycle. In addition, uniform cell-laden microgels are fabricated by introducing the alginate component and rat pancreatic islet (ß-TC6) cell suspension to the dispersed phase. The encapsulated islet cells retain high viability and the function of insulin secretion after cultivation for 7 days. The high-throughput droplet microfluidic system with high biocompatibility is stable, controllable, and flexible, which can boost various chemical and biological applications, such as bio-oriented microparticles synthesizing, microcarriers fabricating, tissue engineering, etc.

Group 5 ITI Consensus Report: Digital technologies.

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.

Multibuilding Block Janus Synthesized by Seed-Mediated Self-Assembly for Enhanced Photothermal Effects and Colored Brownian Motion in an Optical Trap.

The asymmetrical features and unique properties of multibuilding block Janus nanostructures (JNSs) provide superior functions for biomedical applications. However, their production process is very challenging. This problem has hampered the progress of JNS research and the exploration of their applications. In this study, an asymmetrical multibuilding block gold/iron oxide JNS has been generated to enhance photothermal effects and display colored Brownian motion in an optical trap. JNS is formed by seed-mediated self-assembly of nanoparticle-loaded thermocleavable micelles, where the hydrophobic backbones of the polymer are disrupted at high temperatures, resulting in secondary self-assembly and structural rearrangement. The JNS significantly enhances photothermal effects compared to their homogeneous counterpart after near-infrared (NIR) light irradiation. The asymmetrical distribution of gold and iron oxide within JNS also generates uneven thermophoretic force to display active colored Brownian rotational motion in a single-beam gradient optical trap. These properties indicate that the asymmetrical JNS could be employed as a strong photothermal therapy mediator and a fuel-free nanoscale Janus motor under NIR light.

Implant-guided supracrestal alveolar bone growth using scaffolds, BMP-2, and novel scaffold-retaining device.

OBJECTIVE: To evaluate the efficacy of various scaffold systems and a Ti scaffold-retaining device with and without non-glycosylated rhBMP-2 (BMP-2) for increasing the vertical alveolar bone growth in the intra-oral mini-pig model. METHODS: Forty-eight Straumann Bone Level implants with hydrophilic (SLActive) surfaces were partially embedded in mandibles of 12 adult mini-pigs with the shoulder of the implant located 3 mm above the bone crest. Twenty-four implants were placed in conjunction with BMP-2 (50 µg) incorporated within resorbable scaffolds. Twenty-four additional control implants were placed with scaffolds only. Scaffolds were placed around the implant and stabilized with a newly developed Ti "umbrella" scaffold retainer. Scaffolds included (i) HA-coated collagen (Healos); (ii) biphasic HA/ß-TCP crystals (Straumann Bone Ceramic, SBC); and (iii) SBC crystals infused with polyethylene glycol (PEG) hydrogel. Eight test and control pairs for each scaffold group were implanted. At 9 weeks, soft tissue healing was assessed and the extent of new vertical bone was evaluated with microCT and histomorphometry. RESULTS: microCT analysis revealed a mean of 167 ± 47 mm3 new supracrestal mineralized tissue volume formation around the test sites where BMP-2 was released from the scaffold whereas the control group (no BMP-2) showed a significantly lower mineralized tissue volume of 106 ± 55 mm3 . The SBC+BMP-2 group had the highest mineralized tissue volume of 189 ± 36 mm3 . Histomorphometry showed bone-to-implant contact of 54.5% for the test groups and 33.3% for the control groups and new vertical bone growth of 2.2 ± 1.0 and 1.0 ± 0.9 mm, respectively. The SBC+BMP-2 group again demonstrated the best outcome (2.7 ± 0.4 mm). The qualitative scoring of soft tissue dehiscence showed that the presence of BMP-2 yielded far superior outcomes, 0.63 vs. 1.75 for all control implant sites (with scores ranging from 0, reflecting no soft dehiscence, to 4, showing a completely exposed umbrella). CONCLUSION: The release of BMP-2 from a SBC scaffold adjacent to a hydrophilic, rough Ti implant and scaffold retention umbrella consistently regenerated the greatest volume and height of new vertical bone along the length of the implant.

Infected Abdominal Aortic Aneurysms Treated with Extra-anatomic Prosthesis Bypass in the Retroperitoneum.

BACKGROUND: Infected abdominal aortic aneurysms (iAAAs) are rare but life-threatening diseases. The purpose of the present study was to report our experience of extra-anatomic prosthesis bypass in the retroperitoneum as a treatment for iAAAs. METHODS: Data of 8 consecutive patients diagnosed with iAAAs and treated by an extra-anatomic prosthesis bypass in the retroperitoneum were retrospectively collected. Operative details were as follows: one side of the retroperitoneal space was selected to build a track, and a bifurcated expanded polytetrafluoroethylene prosthesis was placed through the track. The proximal end of the prosthesis was sutured with the normal segment of abdominal aorta proximal to the infected aneurysm by end-to-end anostomosis. The 2 distal ends of the prosthesis were, respectively, sutured with the external iliac artery distal to the aneurysm. The anastomoses were then consolidated with the nearby connective tissue. After the closure of the retroperitoneum, the infected aneurysm was incised, and the infected tissue was debrided. Drainage tubes were placed in the aneurysm sac, which was packed with an omentum flap. All patients received perioperative antibiotic therapy for a period of time. All 8 patients were regularly followed up by outpatient observation. RESULTS: Eight patients with iAAAs underwent an extra-anatomic prosthesis bypass in the retroperitoneum and debridement of the infected aneurysm. An emergency operation was performed for 1 patient who underwent concomitant gastrointestinal procedures for aortoduodenal fistula. All 8 patients were definitively diagnosed by one or more sequential computed tomography scans combined with other methods. The blood or tissue cultures of all cases were positive in the perioperative period, with Salmonella (5 cases) being the most common pathogens. Other pathogens included Burkholderia pseudomallei (2 cases) and Escherichia coli (1 case). All patients survived and were discharged in 4-5 weeks after their operations. All patients were free from graft infection during the follow-up period. CONCLUSIONS: The extra-anatomic prosthesis bypass in the retroperitoneum for treating iAAAs was safe and effective. Our experience with the procedure may provide a new approach for the treatment of this disease.

Angle-to-Angle Mandibular Defect Reconstruction With Fibula Flap by Using a Mandibular Fixation Device and Surgical Navigation.

PURPOSE: Although free fibula flaps are widely used for mandibular reconstruction, 3-dimensional (3D) position is difficult to control in angle-to-angle mandibular defects. The present study describes a revised approach for angle-to-angle mandibular reconstruction with fibula flaps by using mandibular fixation device and surgical navigation. METHODS: Preoperative maxillofacial and fibular computed tomography (CT) scans were acquired, and CT data were imported into ProPlan CMF software. Virtual mandibulectomy was performed, and 3D fibula image was superimposed on the mandibular defect. The fibula flap was shaped according to virtual parameters and the stereo model. Surgical navigation was used to check and correct shaped segments. Position of the osteotomy lines and relevant parameters regarding the shape of the fibula flap were provided to the surgeon. A mandibular fixation device (Cibei, China) was fixed to bilateral mandibular ramus before mandibulectomy, which maintained normal mandibular width. Under computer navigation guidance, the fibula flap was accurately positioned in 3D direction, and the defect could be precisely reconstructed despite the lack of stable occlusal relationship after osteotomy. RESULTS: Postoperative CT and 3D error analysis revealed that osteotomy lines and reconstruction contour matched well with preoperative planning. Using our method, we precisely recovered the original configuration of the mandible. Bilateral condyles were located in the temporomandibular joint fossae, and normal mandibular width was maintained. Compared with preoperative positions, the average shift on the remaining mandible was 0.803 ±â€Š0.502 mm (largest, 1.886 mm). Average shift in the reconstructed mandible was 0.281 ±â€Š0.300 mm, largest being 2.441 mm. CONCLUSIONS: We describe a novel method for angle-to-angle mandibular reconstruction with free fibula flap. A mandibular fixation device combined with computer-assisted techniques involving surgical navigation improved clinical outcomes of this procedure.

Comparison of bone morphogenetic protein-2 delivery systems to induce supracrestal bone guided by titanium implants in the rabbit mandible.

OBJECTIVE: To compare the ability of three non-glycosylated/rhBMP-2 (BMP-2) delivery systems to induce supracrestal bone. MATERIAL AND METHODS: Thirty-six custom SLActive dental implants were partially embedded in transverse orientation into the posterior mandibles of 18 adult rabbits with the head of the implant located 3 mm supracrestal. Delivery of BMP-2 (30 µg) from the following materials was studied: (1) Ti implant + BMP-2 with hydroxyapatite (HA)-coated collagen (Col/HA) scaffold, (2) Ti implant with Col/HA infused with PEG hydrogel + BMP-2, or (3) Ti implant with HA/ß-TCP/PEG hydrogel scaffold + BMP-2. Scaffolds were secured with a metal "umbrella." Non-BMP-2 contralateral controls were included. MicroCT imaging and histological analysis was performed after 10 weeks to assess new supracrestal bone formation. In vitro BMP-2 release studies were conducted. RESULTS: All treatment groups displayed new supracrestal bone formation. Ti + BMP-2 with Col/HA (3.0 ± 0.2 mm) and Ti with Col/HA/PEG hydrogel + BMP-2 (2.7 ± 0.4 mm) had significantly greater (P < 0.05) outcomes than without BMP-2. Maximum bone volume occurred in the Ti implant with HA/ß-TCP/PEG hydrogel scaffold + BMP-2 group. CONCLUSIONS: The use of an implant system composed of a partially inserted Ti implant, adjacent scaffold and scaffold stabilizer resulted in the formation of new supracrestal bone across all test groups with and without BMP-2. Delivery of BMP-2 directly from the Ti implant increased bone height, BIC and bone volume as compared to no BMP-2 when a Col/HA was used, but did not improve performance of the HA/ß-TCP/PEG scaffold.

Influence of biphasic calcium phosphate surfaces coated with Enamel Matrix Derivative on vertical bone growth in an extra-oral rabbit model.

OBJECTIVE: The aim of this study was to investigate the ability of Enamel Matrix Derivative (EMD) on vertical bone regeneration around dental implants placed in an extra-oral rabbit model. MATERIAL AND METHODS: A total of 30 Straumann BL implants were partially embedded in transverse orientation into the posterior mandibles of 15 rabbits. Macro-structuring BiPhasicCaPST (BCPT1), micro-structuring BiPhasicCaPST (BCPT2), and deproteinized bovine bone mineral (DBBM) were placed around the implant and covered with a scaffold stabilizing "umbrella." EMD was incorporated within the scaffold for test sites, but not control sites. Histological analysis was performed on retrieved specimens after 10 weeks of healing to assess new bone formation. RESULTS: All treatment groups displayed new supracrestal bone formation as determined by histomorphometric measurements, with mean values of new bone height ranging between 0.62 and 1.13 mm. Histological analysis revealed a higher mean bone formation (%) around the test sites where EMD (34.7, 95%CI: 27.1-39.4) was released from the scaffold, whereas the control group without EMD release (26.4, 95%CI: 16.3-31.9) (P = 0.069). The mean fBIC (%) in the BCPT2 group increased by the addition of EMD relative to no EMD (67.2, 95%CI: 48.6-84.1) and (54.7, 95%CI: 32.3-68.9), respectively). The BCPT2/EMD and DBBM/EMD interventions showed the greatest mean bone density (BA/TA), respectively, (12.8, 95%CI: 8.9-36.5) and (11.2, 6.3-16.4) in ROI 1. Values in ROI 2 were, similarly, (24.9, 95%CI: 17.2-31.7) and (27.7, 19.2-35.3). BA/TA in ROI 2 differences between the BCPT2 groups with and without EMD was statistically significant (P = 0.026), as well as the DBBM groups with and without EMD (P = 0.038). CONCLUSIONS: A layer of new bone was formed in both test and controls. The release of EMD from BCPT2 and DBBM adjacent to a bone-level implant with an SLActive surface and scaffold retention umbrella consistently regenerated the greater fBIC and bone density along the length of the implant.