Prevalence, trend, and associated risk factors for cleft lip with/without cleft palate: a national study on live births from 2016 to 2021.

BACKGROUNDS: Cleft lip with or without cleft palate (CL/P) is the most common congenital craniofacial anomaly, including non-syndromic cleft lip with or without cleft palate and cleft palate only. Failure in the fusion of median and lateral nasal processes, the maxillary prominence, and soft tissues around the oral cavity can cause CL/P. Previously, the prevalence has been estimated to be 1 among every 1000 births in 2014 among American neonates and no other reports have been available since. Thus, this study aimed to calculate the prevalence and trend of isolated CL/P among American live births from 2016 to 2021 with its associated risk factors. METHODS AND MATERIALS: In this cross-sectional population-based retrospective study, we used live birth data provided by the National Center for Health Statistics (NCHS) from the Center for Disease Control and Prevention (CDC). We calculated the prevalence per 10,000 live births of isolated (non-syndromic) CL/P from 2016 to 2021. To examine risk factors for developing isolated CL/P, we used logistic regression modelling. RESULTS: The total prevalence per 10,000 births from 2016 to 2021 was 4.88 (4.79-4.97), for both sexes, and 5.96 (5.82-6.10) for males, and 3.75 (3.64-3.87) for females. The prevalence did not show any consistent linear decreasing or increasing pattern. We found significant association between increased odds of developing isolated CL/P among cases with 20 to 24 year-old mothers (OR = 1.07, 1.01-1.13, p = 0.013), mothers who smoked 11 to 20 cigarettes per day (OR = 1.46, 1.33-1.60, p <  0.001), mothers with extreme obesity (OR = 1.32, 1.21-1.43, p <  0.001), mothers with grade II obesity (OR = 1.32, 1.23-1.42, p <  0.001), mothers with pre-pregnancy hypertension (OR = 1.17, 1.04-1.31, p = 0.009), mothers with pre-pregnancy diabetes mellitus (OR = 1.96, 1.71-2.25, p <  0.001), and mothers who used assisted reproductive technology (OR = 1.40, 1.18-1.66, p <  0.001). CONCLUSIONS: Our findings suggest a minuscule increase, albeit insignificant, in the trend of CL/P prevalence from 2016 to 2021. Developing CL/P had greater odds among mothers with pre-pregnancy diabetes, smoking, obesity, and pre-pregnancy hypertension mothers along with mothers who used assisted reproductive technology. Isolated CL/P had the highest prevalence in non-Hispanic Whites, American Indian or Alaskan Native and Native Hawaiian and Other Pacific Islanders.

Effect of mesenchymal stem cells with platelet-rich plasma carriers on bone formation after rapid maxillary expansion: An Animal Study.

OBJECTIVE: To evaluate the effect of bone mesenchymal stem cells (BMSCs) with or without platelet-rich plasma (PRP) carriers on sutural new bone formation after rapid palatal expansion (RPE). SETTINGS AND SAMPLE POPULATION: Sixty male Wistar rats were used in this study. MATERIAL AND METHODS: All samples were subjected to 50cN of palatal expansion force for 7 days followed by 3 weeks of the retention period. The experimental groups received a single-dose injection of the specified solution at the time of retainer placement (BMSCs, PRP, BMSCs+PRP, normal saline). BMSCs used in this study were marked with the green fluorescent protein (GFP). New bone formation (NBF) in the sutural area was evaluated by µCT and occlusal radiography. In addition, semi-quantitative analyses were performed on histology images to analyse the quality of sutural bone, connective tissue and vascularization. Immunohistochemistry analyses were conducted for osteocalcin and collagen type I proteins. RESULTS: After the 21-day retention period, limited GFP marked cells were detected around the sutural area. Samples treated with BMSCs + PRP had the highest NBF and showed higher expression of collagen type I and osteocalcin. CONCLUSION: Injecting BMSCs + PRP may increase sutural bone density significantly. However, injecting BMSCs or PRP carriers alone did not affect sutural bone density.

Cartilage regeneration with dual-drug-releasing injectable hydrogel/microparticle system: In vitro and in vivo study.

In this study, we developed an injectable in situ forming hydrogel/microparticle system consisting of two drugs, melatonin and methylprednisolone, to investigate the capability of the system for chondrogenesis in vitro and in vivo. The chemical, mechanical, and rheological properties of the hydrogel/microparticle were investigated. For in vitro evaluation, the adipose-derived stem cells might be mixed with hydrogel/microparticles, then cellular viability was analyzed by acridine orange/propidium iodide and 4',6-diamidino-2-phenylindole staining and also dimethylmethylene blue assay were conducted to find the amount of proteoglycan. The real-time polymerase chain reaction for aggrecan, sex-determining region Y-Box 9, collagen I (COL1), and COL2 gene expression was performed after 14 and 21 days. For evaluation of cartilage regeneration, the samples were implanted in rabbit knees with cartilaginous experimental defects. Defects were created in both knees of three groups of rabbits. Group 1 was the control with no injection, and Groups 2 and 3 were loaded with hydrogel/cell and hydrogel/microparticle/cell; respectively. Then, after 3 and 6 months, histological evaluations of the defected sites were carried out. The amount of glycosaminoglycans after 14 and 21 days increased significantly in hydrogels/microparticles loaded with cells. The expression of marker genes was also significant in hydrogels/microparticles loaded with cells. According to histology analysis, the hydrogels/microparticles loaded with cells showed the best cartilage regeneration. Overall, our study revealed that the developed injectable hydrogel/microparticle can be used for cartilage regeneration.

Comparison of osteogenic differentiation potential of induced pluripotent stem cells and buccal fat pad stem cells on 3D-printed HA/ß-TCP collagen-coated scaffolds.

Production of a 3D bone construct with high-yield differentiated cells using an appropriate cell source provides a reliable strategy for different purposes such as therapeutic screening of the drugs. Although adult stem cells can be a good source, their application is limited due to invasive procedure of their isolation and low yield of differentiation. Patient-specific human-induced pluripotent stem cells (hiPSCs) can be an alternative due to their long-term self-renewal capacity and pluripotency after several passages, resolving the requirement of a large number of progenitor cells. In this study, a new biphasic 3D-printed collagen-coated HA/ß-TCP scaffold was fabricated to provide a 3D environment for the cells. The fabricated scaffolds were characterized by the 3D laser scanning digital microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and mechanical test. Then, the osteogenesis potential of the hiPSC-seeded scaffolds was investigated compared to the buccal fat pad stem cell (BFPSC)-seeded scaffolds through in vitro and in vivo studies. In vitro results demonstrated up-regulated expressions of osteogenesis-related genes of RUNX2, ALP, BMP2, and COL1 compared to the BFPSC-seeded scaffolds. In vivo results on calvarial defects in the rats confirmed a higher bone formation in the hiPSC-seeded scaffolds compared to the BFPSC-seeded groups. The immunofluorescence assay also showed higher expression levels of collagen I and osteocalcin proteins in the hiPSC-seeded scaffolds. It can be concluded that using the hiPSC-seeded scaffolds can lead to a high yield of osteogenesis, and the hiPSCs can be used as a superior stem cell source compared to BFPSCs for bone-like construct bioengineering.

Effects of Platelet-Rich Fibrin/Collagen Membrane on Sciatic Nerve Regeneration.

ABSTRACT: Alternative treatment approaches to improve the regeneration ability of damaged peripheral nerves are currently under investigation. The aim of the current study was to evaluate the effects of leucocyte/platelet-rich fibrin (L-PRF) with or without a collagen membrane as a supporter on crushed sciatic nerve healing in a rat model. Recovery of motor function and electrophysiologic measurements were evaluated at 4 weeks postoperatively. The whole number of myelinated axons, peripheral nerve axon density, average nerve fiber diameter (µm), and G-ratio were analyzed and compered among the groups. Functional, electrophysiological, and histological evaluations showed no significant difference among the groups with the exception of the L-PRF with collagen membrane groups that showed relatively positive effects on the functional and histological nerve recovery. In addition, the collagen membrane with L-PRF can be effect in nerve regeneration.

Polyvinyl alcohol modified polyvinylidene fluoride-graphene oxide scaffold promotes osteogenic differentiation potential of human induced pluripotent stem cells.

Tissue engineering is fast becoming a key approach in bone medicine studies. Designing the ideally desirable combination of stem cells and scaffolds are at the hurt of efforts for producing implantable bone substitutes. Clinical application of stem cells could be associated with serious limitations, and engineering scaffolds that are able to imitate the important features of extracellular matrix is a major area of challenges within the field. In this study, electrospun scaffolds of polyvinylidene fluoride (PVDF), PVDF-graphene oxide (GO), PVDF-polyvinyl alcohol (PVA) and PVDF-PVA-GO were fabricated to study the osteogenic differentiation potential of human induced pluripotent stem cells (iPSCs) while cultured on fabricated scaffolds. Scanning electron microscopy study, viability assay, relative gene expression analysis, immunocytochemistry, alkaline phosphates activity, and calcium content assays confirmed that the osteogenesis rate of hiPSCs cultured on PVDF-PVA-Go is significantly higher than other scaffolds. Here, we showed that the biocompatible, nontoxic, flexible, piezoelectric, highly porous and interconnected three-dimensional structure of electrospun PVDF-PVA-Go scaffold in combination with hiPSCs (as the stem cells with significant advantageous in comparison to other types) makes them a highly promising scaffold-stem cell system for bone remodeling medicine. There was no evidence for the superiority of PVDF-GO or PVDF-PVA scaffold for osteogenesis, compared to each other; however both of them showed better potentials as to PVDF scaffold.

MicroRNA-218 competes with differentiation media in the induction of osteogenic differentiation of mesenchymal stem cell by regulating ß-catenin inhibitors.

Osteoporosis, a systemic skeletal disorder specified by low bone mass, is associated with bone fragility and the raised risk of fractures. Activation of the Wnt/ß-catenin signaling pathway has been directly demonstrated as a prominent biological event in the prevention of osteoporosis. Recently, critical roles of microRNAs (miRNAs) were further revealed in Wnt/ß-catenin signaling activation and thereby contributing to the development and maintenance of the human skeleton. In this study, we investigated whether miR-218 can significantly promote the osteogenic differentiation of mesenchymal stem cells in conditional media by regulating ß-catenin signaling inhibitors. The pre-miRNA nucleotide sequence of miR-218 was cloned into the pEGP-miR vector. Next, human adipose tissue-derived mesenchymal stem cells (AD-MSCs) were isolated, characterized, and transfected using pEGP-miR-218.Subsequently, the osteogenic potential of AD-MSCs was investigated in different treated groups using alkaline phosphatase (ALP)activity, calcium mineral deposition, and the expression of osteogenesis-related genes. Finally, negative regulators of Wnt signaling targeted by miR-218 were bioinformatically predicted. Our results indicated a significant increase in the ALP activity, mineralization, and osteogenesis-related genes expression in the AD-MSCs transfected with pEGP-miR-218. Also, the bioinformatic surveys and gene expression results showed that adenomatosis polyposis coli (APC) and glycogen synthase kinase 3 (GSK3-ß) were downregulated in the transfected AD-MSCs in both differential and conditional media. This study provided evidence that miR-218 can promote osteogenic differentiation of AD-MSCs even in conditional media. Therefore, our findings suggest miR-218 as a putative novel therapeutic candidate in the context of osteoporosis and other bone metabolism-related diseases.

Bone tissue engineering gelatin-hydroxyapatite/graphene oxide scaffolds with the ability to release vitamin D: fabrication, characterization, and in vitro study.

Developing smart scaffolds with drug release capability is one of the main approaches to bone tissue engineering. The current study involves the fabrication of novel gelatin (G)-hydroxyapatite (HA)-/vitamin D (VD)-loaded graphene oxide (GO) scaffolds with different concentrations through solvent-casting method. Characterizations confirmed the successful synthesis of HA and GO, and VD was loaded in GO with 36.87 ± 4.87% encapsulation efficiency. Physicochemical characterizations showed that the scaffold containing 1% VD-loaded GO had the best mechanical properties and its porosity percentage and density was in the range of natural spongy bone. All scaffolds were degraded after 1-month, subjecting to phosphate buffer saline. The release profile of VD did not match any mathematical kinetics model, porosities and the degradation rate of the scaffolds were dominant controlling factors of release behavior. Studies on the bioactivity of scaffolds immersed in simulated body fluid indicated that VD and HA could encourage the formation of secondary apatite crystals in vitro. Buccal fat pad-derived stem cells (BFPSCs) were seeded on the scaffolds, MTT assay, alkaline phosphatase activity as an indicator of osteoconductivity, and cell adhesion were conducted in order to evaluate in vitro biological responses. All scaffolds highly supported cell adhesion, MTT assay indicated better cell viability in 0.5% VD-loaded GO containing scaffold, and the scaffold enriched with 2% VD-loaded GO performed the most ALP activity. The results demonstrated the potential of these scaffolds to induce bone regeneration. Developing smart scaffolds with drug release capability is one of the main approaches to bone tissue engineering. The current study involves the fabrication of novel gelatin (G)-hydroxyapatite (HA)-/vitamin D (VD)-loaded graphene oxide (GO) scaffolds with different concentrations through solvent-casting method. Characterizations confirmed the successful synthesis of HA and GO, and VD was loaded in GO with 36.87 ± 4.87% encapsulation efficiency. Physicochemical characterizations showed that the scaffold containing 1% VD-loaded GO had the best mechanical properties and its porosity percentage and density was in the range of natural spongy bone. All scaffolds were degraded after 1-month, subjecting to phosphate buffer saline. The release profile of VD did not match any mathematical kinetics model, porosities and the degradation rate of the scaffolds were dominant controlling factors of release behavior. Studies on the bioactivity of scaffolds immersed in simulated body fluid indicated that VD and HA could encourage the formation of secondary apatite crystals in vitro. Buccal fat pad-derived stem cells (BFPSCs) were seeded on the scaffolds, MTT assay, alkaline phosphatase activity as an indicator of osteoconductivity, and cell adhesion were conducted in order to evaluate in vitro biological responses. All scaffolds highly supported cell adhesion, MTT assay indicated better cell viability in 0.5% VD-loaded GO containing scaffold, and the scaffold enriched with 2% VD-loaded GO performed the most ALP activity. The results demonstrated the potential of these scaffolds to induce bone regeneration.

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) improved osteogenic differentiation of the human induced pluripotent stem cells while considered as an artificial extracellular matrix.

Cocell polymers can be the best implants for replacing bone defects in patients. The pluripotent stem cells produced from the patient and the nanofibrous polymeric scaffold that can be completely degraded in the body and its produced monomers could be also usable are the best options for this implant. In this study, electrospun poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers were fabricated and characterized and then osteogenic differentiation of the human-induced pluripotent stem cells (iPSCs) was investigated while cultured on PHBV scaffold. MTT results showed that cultured iPSCs on PHBV proliferation were increased compared to those cultured on tissue culture polystyrene (TCPS) as the control. Alkaline phosphatase (ALP) activity and calcium content were also significantly increased in iPSCs cultured on PHBV compared to the cultured on TCPS under osteogenic medium. Gene expression evaluation demonstrated that Runx2, collagen type I, ALP, osteonectin, and osteocalcin were upregulated in iPSCs cultured on PHBV scaffold in comparison with those cultured on TCPS for 2 weeks. Western blot analysis have shown that osteocalcin and osteopontin expression as two major osteogenic markers were increased in iPSCs cultured on PHBV scaffold. According to the results, nanofiber-based PHBV has a promising potential to increase osteogenic differentiation of the stem cells and iPSCs-PHBV as a cell-co-polymer construct demonstrated that has a great efficiency for use as a bone tissue engineered bioimplant.

Promoting osteogenic differentiation of human-induced pluripotent stem cells by releasing Wnt/ß-catenin signaling activator from the nanofibers.

Implants that can enhance the stem cells differentiation in the absence of the chemical osteogenic growth factors will attract the great interest of orthopedic scientists. Inorganic polyphosphate (poly-P), as a ubiquitous biological polymer, is one of the factors that can be an alternative for osteogenic growth factors via activating Wnt/ß-catenin signaling. In this study, poly-P was incorporated at the blend of polycaprolactone (PCL)/poly (l-lactic acid) (PLLA) electrospun nanofibers and then osteogenic differentiation potential of human-induced pluripotent stem cells (iPSCs) was investigated by the important bone markers. 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide (MTT) and scanning electron microscopy results confirmed the biocompatibility of the fabricated nanofibers, while higher proliferation rate of iPSCs was detected in PCL-PLLA(poly-P) group compared with the PCL-PLLA and tissue culture plate groups. Alkaline phosphatase activity, calcium content, and gene expression results demonstrated that osteogenic differentiation of iPSCs was increased when cultured on PCL-PLLA(poly-P) in comparison with other groups. According to the results, PCL-PLLA(poly-P) could be considered as a promising candidate for use as bone implants.

Biological behavior of the curcumin incorporated chitosan/poly(vinyl alcohol) nanofibers for biomedical applications.

Electrospun composite scaffolds show high ability to be used in regenerative medicine and drug delivery, due to the nanofibrous structure and high surface area to volume ratio. In this study, we used nanofibrous scaffolds fabricated by chitosan (CS), poly(vinyl alcohol) (PVA), carbopol, and polycaprolactone using a dual electrospinning technique while curcumin (Cur) incorporated inside of the CS/PVA fibers. Scaffolds were fully characterized via scanning electron microscopy, water contact angle, tensile measurement, hydration, protein adsorption, and wrinkled tests. Furthermore, viability of the buccal fat pad-derived mesenchymal stem cells (BFP-MSCs) was also investigated using MTT assay for up to 14 days while cultured on these scaffolds. Cell cycle assay was also performed to more detailed evaluation of the stem cells growth when grown on scaffolds (with and without Cur) compared with the culture plate. Results demonstrated that Cur loaded nanofibrous scaffold had more suitable capability for water absorption and mechanical properties compared with the scaffold without Cur and it could also support the stem cells viability and proliferation. Cur release profile showed a decreasing effect on BFP-MSCs viability in the initial stage, but it showed a positive effect on stem cell viability in a long-term manner. In general, the results indicated that this nanofibrous scaffold has great potential as a delivery of the Cur and BFP-MSCs simultaneously, and so holds the promising potential for use in various regenerative medicine applications.

Immediate implant placement following 1-year treatment with oral versus intravenous bisphosphonates: a histomorphometric canine study on peri-implant bone.

OBJECTIVES: Bisphosphonates (BPs) are anti-resorptive medications with inhibitory effects on osteoclasts which decrease bone turnover. The present study aimed to assess the early effects of BPs on peri-implant bone. MATERIALS AND METHODS: Twelve female mongrel dogs were assigned to one control and two experimental groups as follows: 12 months of oral alendronate (ALN, 3.5 mg/kg/week) or intravenous (IV) pamidronate (PAM, 1 mg/kg/week) for experimental groups. Following 8 weeks after implant insertion, the specimens were sacrificed, histological evaluation was performed, and C-terminal telopeptide of collagen I (CTx) analysis was performed on serums. RESULTS: PAM demonstrated the greatest marginal bone level (MBL), 2.64 ± 0.48, followed by ALN and control, 2.5 ± 0.4 and 0.66 ± 0.5 respectively. The least bone-implant contact was observed in PAM group (%39 ± 0.03) while it was significantly greater in the control group (p < 0.05). PAM and ALN demonstrated < 10 CTx levels versus > 300 in controls. CONCLUSION: It is assumed that long-term oral or IV BP therapy decreases marginal bone resorption and osseointegration. These changes were more accentuated in IV BP administration. CTx does not seem to be a precise predictor for bisphosphonate-related osteonecrosis of the jaw. CLINICAL RELEVANCE: BPs impair peri-implant bone remodeling and this phenomena may be effective for reducing resorption at esthetic zone implants; however, decrease in osseointegration may be a concern for implant treatment in patients receiving BPs.

Buccal Fat Pad-Derived Stem Cells in Three-Dimensional Rehabilitation of Large Alveolar Defects: A Report of Two Cases.

This case report seeks to describe efficient clinical application of adipose-derived stem cells (AdSCs) originated from buccal fat pad (BFP) in combination with conventional guided bone regeneration as protected healing space for reconstruction of large alveolar defects after extraction of multiple impacted teeth. The first case was a 19-year-old woman with several impacted teeth in the maxillary and mandibular regions, which could not be forced to erupt and were recommended for surgical extraction by the orthodontist. After this procedure, a large bone defect was created, and this space was filled by AdSC loaded natural bovine bone mineral (NBBM), which was protected with lateral ramus cortical plates, microscrews, and collagen membrane. After 6 months of post-guided bone regeneration, the patient received 6 and 7 implant placements, respectively, in the maxilla and mandible. At 10 months postoperatively, radiographic evaluation revealed thorough survival of implants. The second case was a 22-year-old man with the same complaint and large bony defects created after his teeth were extracted. After 6 months of post-guided bone regeneration, he received 4 dental implants in his maxilla and 7 implants in the mandible. At 48 months postoperatively, radiographs showed complete survival of implants. This approach represented a considerable amount of 3-dimensional bone formation in both cases, which enabled us to use dental implant therapy for rehabilitation of the whole dentition. The application of AdSCs isolated from BFP in combination with NBBM can be considered an efficient treatment for bone regeneration in large alveolar bone defects.

Different Porosities of Chitosan Can Influence the Osteogenic Differentiation Potential of Stem Cells.

Scaffolds porosity has an important role in in vitro and in vivo differentiation process of stem cells with given the amount of space available to the cells to proliferate and differentiate. In the present study, chitosan with three porosities including 10%, 15%, and 20% that created by gelatin were used for investigation of the proliferation and osteogenic differentiation potential of adipose-derived stem cells (ADSCs). In order to be more like the scaffold to natural bone tissue, freeze-drying method was used in the scaffold preparation. Scaffold morphology, cell attachment, and toxicity were evaluated using scanning electron microscopy and MTT assay. Then, osteogenic differentiation potential of ADSCs cultured on chitosan with different porosities was evaluated by common osteogenic markers such as Alizarin red staining, ALP activity, calcium content, and osteogenic-related genes expression via real-time RT-PCR. Although all scaffolds supported the proliferation and differentiation of ADSCs, but 10% scaffold demonstrated higher amount of osteogenic markers in comparison with the other porosities and control groups. Taking together, it can be concluded that osteogenic differentiation well done in the scaffolds with lower porosity because density of the cells will increase by forcing resulted from the scaffold, so osteogenic differentiation of the stem cells have an inverse association with scaffold porosity. J. Cell. Biochem. 119: 625-633, 2018. © 2017 Wiley Periodicals, Inc.

The power of precise bioinformatics prediction of miRNA:mRNA interactions:miR-4699 as a potential inducer of Wnt signaling pathway.

microRNAs have attracted interest because of their regulatory effects on gene expression. Experimental detection of potential targets of miRNAs is a laborious task. Considering the expensive techniques of detection, computational approaches for miRNA target prediction can be used as the first step in miRNA research. A large number of tools and algorithms have been developed during the last two decades, led to problems such as confusion in selecting an appropriate tool and false positive or negative results. Therefore, one of the most frequent problems and critical issues of miRNA research is finding a reliable miRNA target prediction tool. In this study, we have proposed a research direction and introduced user-friendly and current databases and tools with the highest accuracy. To verify whether our proposed research direction is practical, we have provided a case example of predicting a miRNA which can target negative regulators of osteogenesis and experimentally evaluated the accuracy of the prediction results by Real-Time PCR and Luciferase assay. The results of RT-qPCR and Luciferase assay indicated a significant decline in expression of Dickkopf-related protein 1 (DKK1) and tumor necrosis factor ligand superfamily member 11 (TNFSF11) as the key negative regulators of osteogenesis upon overexpression of miR-4699-3p. The results emphasize the validity and importance of accurate in silico investigation as the first step in experimental studies. This is the first report detailing the prediction and validation of miR-4699-3p target genes. We suggest hsa-miR-4699 for further investigation as an osteogenic miRNA for therapeutics purposes.

Polyurethane/Gelatin Nanofibrils Neural Guidance Conduit Containing Platelet-Rich Plasma and Melatonin for Transplantation of Schwann Cells.

The current study aimed to enhance the efficacy of peripheral nerve regeneration using a biodegradable porous neural guidance conduit as a carrier to transplant allogeneic Schwann cells (SCs). The conduit was prepared from polyurethane (PU) and gelatin nanofibrils (GNFs) using thermally induced phase separation technique and filled with melatonin (MLT) and platelet-rich plasma (PRP). The prepared conduit had the porosity of 87.17 ± 1.89%, the contact angle of 78.17 ± 5.30° and the ultimate tensile strength and Young's modulus of 5.40 ± 0.98 MPa and 3.13 ± 0.65 GPa, respectively. The conduit lost about 14% of its weight after 60 days in distilled water. The produced conduit enhanced the proliferation of SCs demonstrated by a tetrazolium salt-based assay. For functional analysis, the conduit was seeded with 1.50 × 104 SCs (PU/GNFs/PRP/MLT/SCs) and implanted into a 10-mm sciatic nerve defect of Wistar rat. Three control groups were used: (1) PU/GNFs/SCs, (2) PU/GNFs/PRP/SCs, and (3) Autograft. The results of sciatic functional index, hot plate latency, compound muscle action potential amplitude and latency, weight-loss percentage of wet gastrocnemius muscle and histopathological examination using hematoxylin-eosin and Luxol fast blue staining, demonstrated that using the PU/GNFs/PRP/MLT conduit to transplant SCs to the sciatic nerve defect resulted in a higher regenerative outcome than the PU/GNFs and PU/GNFs/PRP conduits.

The influence of initial alveolar ridge defect morphology on the outcome of implants in augmented atrophic posterior mandible: an exploratory retrospective study.

OBJECTIVES: Clinicians commonly consider atrophic site topography as an important determinant in deciding the augmentation technique to utilize, as well as forecasting the likelihood of success. The purpose of this retrospective study was to examine the influence of initial atrophic posterior mandible morphology on the outcome of implants placed following augmentation. MATERIALS AND METHODS: A total of 52 patients contributed 71 edentulous sites, and 185 implants were placed with mean follow-up of 37.97 months. The initial defect morphology was classified according to ABC classification (Journal of Oral Implantology, 37, 2013a and 361). Ridge augmentation was performed by "cortical autogenous tenting" (CAT) followed by either simultaneous or delayed implant placement after 4-6 months of healing. The European Academy of Osseointegration success criteria were used to evaluate implant outcomes. RESULTS: The overall survival and success rates of dental implants were 98.91% and 80%, respectively. Cumulative success and survival rates in CAT group were 95% and 100% after 2 years of follow-up. The highest marginal bone loss (MBL) was observed (1.26 mm ± 0.99) around implants placed in augmented edentulous sites with initially narrow and flat alveolar crest (defect class CII). Conversely, least MBL (0.48 mm ± 0.78) was detected around implants placed into edentulous sites with two sloped boney walls (defect class AII). Differences between MBL observed around implants placed into initial defect class C, initial defect type and class A (I, II), as well as class BII, were statistically significant (P < 0.05). Among all implants, 148 were considered as successful, 26 exhibited satisfactory survival, nine with compromised survival, and two implants failed. CONCLUSION: The present data confirmed the effect of initial ridge morphology on the outcome of implants placed into augmented bone. Specifically, class A and class B atrophic ridge defects, with one and two vertical boney walls, respectively, may be considered as more favorable recipient sites than class C defects with flat morphology. This conclusion is based on least MBL around implants placed into initial defect class A and class B augmented sites, and higher MBL in implants placed into class C recipient sites. A randomized controlled trial is warranted to examine these exploratory observations.

Healing Effects of Platelet-Rich Plasma on Peripheral Nerve Injuries.

Regeneration of peripheral nerve injuries (PNIs) has been a major challenging issue in regenerative medicine and tissue engineering. Inferior alveolar nerve and lingual nerve injuries are the major difficulties and complications of oral surgeries following dental implant placement, etc. The aim of this study was to systematically review the effects of platelet-rich plasma (PRP) on the regeneration of PNIs. Medline NCBI databases were searched for related articles up to and including May 2016. Being published in English papers, use of PRP in peripheral nerve regeneration, in vivo studies, and having histological evaluations was the inclusion criteria. Seventeen papers were selected according to the inclusion and exclusion criteria, and categorized regarding PNIs types including cut or crushed injuries. The effects of using PRP only or in combination with cells on the functional recovery and histological assessments are discussed and compared with the other treatments such as autologous nerve graft, acellular nerve allograft, and synthetic nerve conduits. The authors also clarified the perspectives in the current field. Consequently, PRP demonstrated positive effects on healing of the nerve function as well histological improvements in cut nerve PNIs model; however, more studies in the field of crushed nerves are needed to arrive at an evidence-based conclusion.

Functional synergy of anti-mir221 and nanohydroxyapatite scaffold in bone tissue engineering of rat skull.

An appropriate cell source, effective cell modification, and proper supportive matrices are the main bases of tissue engineering. The effectiveness of anti-mir221 or hydroxyapatite (HA) in improving the osteogenic differentiation of mesenchymal stem cells (MSCs) has been reported previously. Herein, simultaneous application of these osteogenic inducers was investigated in vivo. The Poly-caprolactone (PCL)/HA nanofibers were characterized using contact angle measurement, tensile test, Fourier transform infrared spectroscopy, and electron microscopy. Rat MSCs were isolated, characterized and transfected with anti-mir221. The rats were divided into 4 groups and an 8 mm defect were created in the mid-calvaria of each rat by trephine bur. Group 1 received (PCL)/HA nanofibers, group 2 received (PCL)/HA nanofibers plus autologous MSCs, group 3 received (PCL)/HA nanofibers plus MSCs transfected with anti-mir221, and group 4 rats were left empty as an additional control group. Histomorphometric and radiomorphometric evaluation after 4 and 8 weeks revealed more new bone formation in the cell-treated groups compared to the scaffold alone group. There was evidence for a combination of increased osteoclasts and osteoblast vascular lake containing red blood cells in the anti-mir221 transfected group. New bone penetration into the scaffolds empirically demonstrated the capability of this combination for efficient osteointegration. Altogether, the co-application of HA and anti-mir221 transfected cells can enhance bone healing of the rat skull.

Effect of Microthread Design on Marginal Bone Level Around Dental Implants Placed in Fresh Extraction Sockets.

PURPOSE: This study was designed to compare radiographically the effect of microthread on the coronal portion of the fixture on marginal bone level (MBL) around immediately placed dental implants in human subjects. MATERIAL AND METHODS: Forty-one roughened surface screw type Dentium oral implants (Dentium) were inserted in fresh extraction sockets of the anterior segment of maxilla of 30 patients. The implants were selected randomly using either microthread design on coronal portion of the fixture (Implantium) (test group) or without microthread thread design (Superline) (control group). MBL was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: At month 3, the microthread groups have been associated with more marginal bone loss than the control group (P = 0.04). At months 6 and 12, both groups had comparable bone levels (P = 0.21). CONCLUSION: The microthread design of the implant collar could not have a positive effect in maintaining the MBL around implants placed in fresh extraction socket in anterior maxilla.