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Mesenchymal stem cells (MSCs) immunologically trained using lipopolysaccharide (LPS) display enhanced immunomodulatory capabilities. Extracellular vesicles (EVs) derived from MSCs are widely used in regenerative medicine owing to their bioactive properties without the drawbacks of cell therapy. However, it remains unclear whether EVs derived from LPS-stimulated (trained) MSCs (L-EVs) inherit the enhanced reparative potential from their parent cells. Thus, this study first aims to explore the effect of immunological training on the bioactivity of L-EVs. LPS-trained bone marrow-derived MSCs (BMSCs) secrete more EVs, and these EVs significantly promote M2 macrophage polarization. Subsequently, hydrogel systems based on thixotropic injectable silk fibroin are prepared for in vivo EV delivery. These hydrogels have controllable gelation time and exhibit outstanding reparative effects on rat skin wounds and alveolar bone defects. Finally, it is revealed that L-EVs promote M2 macrophage polarization by inhibiting the nuclear translocation of PKM2. Overall, this study shows that the immunological training of BMSCs effectively improves the therapeutic effects of their EVs and provides a convenient and diversified EV delivery strategy using an injectable silk fibroin hydrogel. This strategy has broad clinical application prospects for tissue regeneration.

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BACKGROUND: To three-dimensionally evaluate changes of the alveolar bone around the mandibular anterior teeth and pharyngeal airway dimensions in adults with Class III malocclusion before and after orthodontic treatment of mandibular dentition distalization. METHODS: In this retrospective study, cone-beam computed tomography (CBCT) scans of 20 patients with Class III malocclusion who underwent mandibular dentition distalization were obtained both before and after treatment. Three-dimensional changes of the thickness and vertical marginal bone levels around mandibular incisors and canines were assessed and compared. And airway volumes of the palato-, glosso-, laryngopharynx and the minimum axial area were measured and compared before and after treatment. RESULTS: A significant decrease of lingual bone thickness of mandibular incisors, partial labial and lingual bone thickness of canines were observed (P < 0.05). The reduction in root length of incisors and canines, labial and lingual vertical marginal bone levels were significant after orthodontic treatment. No significant correlations between mandibular dentition distalization and pharyngeal airway dimensions were observed. CONCLUSIONS: Mandibular dentition distalization could result in the loss of alveolar bone around anterior teeth in Class III malocclusion, especially for the cervical marginal bone. Pharyngeal airway dimensions were not affected to a high extent after distalization. TRIAL REGISTRATION: Retrospctively registered.

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Hydrogels are considered to be ideal biomedical materials as their physical properties are similar to the physiological tissue environment. In particular, thixotropic hydrogels have received increasing attention from researchers because of their injectability. Herein, a simple and rapid method was developed for the preparation of a regenerated silk fibroin (RSF) hydrogel with long-lasting and excellent thixotropy. The thixotropic RSF hydrogel was readily formed by ultrasonic treatment of the pretreated RSF solution for 2 min followed by incubation at 40 °C for 10 min. The storage modulus of the RSF hydrogels recovered to more than 90% of the original value within 20 s after withstanding 1000% shear strain. By avoiding complicated chemical or physical treatments and by addition of crosslinking agents and/or other chemical components, the obtained RSF hydrogels maintained excellent biocompatibility. Hence, the cells implanted inside the hydrogel can grow and proliferate normally. By virtue of ultrasonic treatment during the preparation, functional nanoparticles can be uniformly dispersed in the RSF solution to prepare RSF-based hybrid hydrogels with various functions. As an application example, hydroxyapatite (HAP) with osteoinductivity was mixed with RSF solution to prepare the RSF/HAP hybrid hydrogel. The RSF/HAP hybrid hydrogel maintained biocompatibility and thixotropy of the original RSF hydrogel and promoted osteoblastic differentiation of cells owing to the addition of HAP. Therefore, the RSF hydrogel prepared in this work has a strong application prospect in the biomedical field including, but not limited to, bone repair.

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Silk fibroin is regarded as a promising biomaterial in various areas, including bone tissue regeneration. Herein, Laponite® (LAP), which can promote osteogenic differentiation, was introduced into regenerated silk fibroin (RSF) to prepare an RSF/LAP hybrid hydrogel. This thixotropic hydrogel is injectable during the operation process, which is favorable for repairing bone defects. Our previous work demonstrated that the RSF/LAP hydrogel greatly promoted the osteogenic differentiation of osteoblasts in vitro. In the present study, the RSF/LAP hydrogel was found to have excellent biocompatibility and significantly improved new bone formation in a standard rat calvarial defect model in vivo. Additionally, the underlying biological mechanism of the RSF/LAP hydrogel in promoting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was extensively explored. The results indicate that the RSF/LAP hydrogels provide suitable conditions for the adhesion and proliferation of BMSCs, showing good biocompatibility in vitro. With the increase in LAP content, the alkaline phosphatase (ALP) activity and mRNA and protein expression of the osteogenic markers of BMSCs improved significantly. Protein kinase B (AKT) pathway activation was found to be responsible for the inherent osteogenic properties of the RSF/LAP hybrid hydrogel. Therefore, the results shown in this study firmly suggest such an injectable RSF/LAP hydrogel with good biocompatibility (both in vitro and in vivo) would have good application prospects in the field of bone regeneration.

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Porous scaffolds hold promise in the treatment of bone defects for bone tissue engineering due to their interconnected porous structure and suitable mechanical properties. Herein, LAPONITE® (LAP), which is able to promote osteogenic differentiation, was introduced into regenerated silk fibroin (RSF) porous scaffolds. Due to hydrogen bonding and electrostatic interactions between RSF and LAP, RSF/LAP 3D porous scaffolds were successfully prepared. The pore size, porosity, and mechanical properties of the RSF/LAP 3D porous scaffolds were modulated during the preparation process. Evaluation of the proliferation of bone marrow mesenchymal stem cells (BMSCs) on the RSF/LAP 3D porous scaffolds in vitro indicated that the addition of LAP improved the adhesion and proliferation of cells. Additionally, alkaline phosphatase activity and osteospecific gene expression analysis showed that the RSF/LAP 3D porous scaffolds enhanced the osteogenic differentiation of BMSCs compared to the pristine RSF porous scaffolds, especially with a higher LAP content. The subcutaneous implantation of the RSF/LAP 3D porous scaffolds in rats demonstrated good histocompatibility in vivo. Therefore, RSF/LAP 3D porous scaffolds with good biocompatibility and biodegradability have good application prospects in the field of bone tissue engineering.

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Silk fibroin is a natural polymer that has various material forms and wide applications. Hydrogel is one of the most attractive silk materials because of its hydrophilicity, biocompatibility, and flexibility. However, its applications are still quite limited because they have a complicated preparation process and/or low mechanical strength. Herein, a simple way to prepare tough silk fibroin hydrogels via a solvent-exchange method is introduced. The degummed silk fiber was directly dissolved in a calcium chloride/formic acid solution and then water was used to replace the solvent. The silk fibroin hydrogel that was obtained using this facile method exhibited even better mechanical properties than most silk fibroin hydrogels that have been reported in the literature. Also, the silk fibroin hydrogel maintained biocompatibility that was as good as that prepared via other methods. Finally, the possibility of using this regenerated silk fibroin hydrogel as a multi-functional platform (such as a catalyst carrier, photothermal agent, and underwater adhesive) has been discussed. Therefore, such a natural, sustainable, robust, and good biocompatible silk fibroin hydrogel that is prepared by an improved method may have great potential for further applications.

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OBJECTIVES: The purpose of this study was to investigate the prevalence of alveolar bone dehiscence and fenestration of Class I individuals with normality patterns in the anterior region using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 4715 retrospective cases from January 2018 to December 2020 in the Orthodontic Department of xxx Hospital were screened. Sixty-one cases were Class I individuals with normality patterns in the anterior region. Their incidence of dehiscence and fenestration in the anterior teeth region was studied and statistically analyzed. RESULTS: Dehiscence was found in 27.46% of the evaluated anterior teeth and fenestration was found in 26.91% of anterior teeth. Severe dehiscences and fenestrations mainly occurred in mandibular canines and maxillary canines, respectively. Alveolar bone defects were present in 100% of patients, while one patient had alveolar bone defects in 91.67% of the anterior teeth. CONCLUSIONS: Dehiscence was found in 27.46% of the anterior teeth of Class I individuals with normality patterns, while fenestration was found in 26.91% of them. Alveolar bone defects were present in 100% of patients. CLINICAL RELEVANCE: Alveolar bone dehiscence and fenestration were normal and common in our sample, indicating that they are more likely to be physiological rather than pathological defects. Orthodontists should be aware of the presence and severity of these defects before treatment in order to avoid both possible complications and overtreatment.

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BACKGROUND: Oral health and esthetic concerns have increasingly motivated adults with periodontitis to seek orthodontic care. Patients with periodontitis often have other dental complications that can make treatment more challenging or less likely to be successful. The predictability of multidisciplinary regenerative and orthodontic treatment approaches in a patient with periodontitis, thin periodontal phenotype, and anterior crossbite is described. CASE DESCRIPTION: A 35-year-old man was designated as having a high risk of experiencing soft-tissue recession owing to his thin periodontal phenotype. After the initial periodontal therapy, clear aligners were used to eliminate the anterior crossbite that was causing traumatic occlusion. In addition, a subepithelial connective tissue graft was used to alter the thin periodontal phenotype. Three months later, guided bone regeneration with corticotomy was performed to increase bone mass, and orthodontic traction was used at 2 weeks after surgery. Orthodontic treatment was continued until all the spaces had been closed. Clinical and radiographic evaluations conducted at the 6-month follow-up revealed substantial improvements in both the soft- and hard-tissue phenotypes. PRACTICAL IMPLICATIONS: Outcomes in this case indicate that sequential soft- and hard-tissue augmentation, after eliminating traumatic occlusion via using a clear aligner, may be a valuable approach for improving soft- and hard-tissue support in patients with periodontitis.

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PURPOSE: Obesity is a worldwide metabolic disease and a critical risk factor for several chronic conditions. Obstructive sleep apnea (OSA) is an important complication of obesity. With the soaring morbidity of obesity, the prevalence of OSA has markedly increased. However, the underlying mechanism of the high relevance between obesity and OSA has not been elucidated. This study investigated the effects of obesity on the structure and function of the genioglossus to explore the possible mechanisms involved in OSA combined with obesity. METHODS: Six-week-old male C57BL/6J mice were fed high-fat diet (HFD, 60% energy) or normal diet (Control, 10% energy) for 16 weeks. The muscle fibre structure and electromyography (EMG) activity of genioglossus were measured. The ultrastructure and function of mitochondrial, oxidative damage and apoptosis in genioglossus were detected by transmission electron microscopy (TEM), qPCR, Western blotting, immunohistochemistry and TUNEL staining. We further studied the influence of palmitic acid (PA) on the proliferation and myogenic differentiation of C2C12 myoblasts, as well as mitochondrial function, oxidative stress, and apoptosis in C2C12 myotubes. RESULTS: Compared with the control, the number of muscle fibres was decreased, the fibre type was remarkably changed, and the EMG activity had declined in genioglossus. In addition, a HFD also reduced mitochondria quantity and function, induced excessive oxidative stress and increased apoptosis in genioglossus. In vitro, PA treatment significantly inhibited the proliferation and myogenic differentiation of C2C12 myoblasts. Moreover, PA decreased the mitochondrial membrane potential, upregulated mitochondrial reactive oxygen species (ROS) levels, and activated the mitochondrial-related apoptotic pathway in myotubes. CONCLUSION: Our findings suggest that a HFD caused genioglossus injury in obese mice. The mitochondrial dysfunction and the accompanying oxidative stress were involved in the genioglossus injury, which may provide potential therapeutic targets for OSA with obesity.

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BACKGROUND: Epidemiological data on malocclusion among Chinese children are scant. The aim of this study was to provide detailed information on the prevalence of malocclusion in early mixed dentition children in Shanghai, China. METHODS: A cross-sectional survey was conducted from September 2016 to April 2017, and 2,810 children aged 7- to 9- years were selected from 10 primary schools by cluster random sampling. Several occlusal parameters, including Angle molar relationship, overjet, overbite, open bite, anterior and posterior crossbite, midline displacement, scissors bite, and teeth crowding and spacing, were clinically registered by five calibrated orthodontic dentists. RESULTS: We found that 79.4% children presented one or more occlusal anomalies. Angle Class I, Class II and Class III molar relationship were recorded in 42.3%, 50.9% and 5.9% of the sample, respectively. The proportion of Class III increased from 5.0% at age 7 to 7.8% at age 9. In the sagittal plane, increased overjet >3 mm was observed in 40.8% subjects, while the prevalence of severe overjet (>8 mm), anterior edge-to-edge (zero overjet) and anterior crossbite were 5.2%, 8.1% and 10.5%, respectively. Vertically, deep overbite >2/3 overlap was found in 6.2% of the children and open bite in 4.3%. Boys exhibited a higher rate of overbite than girls. For the transversal occlusal anomalies, 36.1% of the children had a midline displacement, which was followed by posterior crossbite (2.6%) and scissors bite (1.0%). Teeth space discrepancies were also common anomalies and anterior crowding (>2 mm) affecting 28.4% of the children, while anterior spacing (>4 mm) affecting 9.5%. Girls showed a higher prevalence of anterior crowding and a lower frequency of teeth spacing than boys. CONCLUSIONS: Our study demonstrated that malocclusion is prevalent among children in the early mixed dentition, and more health resources should be warranted to meet the challenge of prevention or early intervention of malocclusion.

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BACKGROUND: To evaluate the changes of alveolar dehiscence and fenestration after augmented corticotomy-assisted orthodontic treatment on cone-beam computed tomography (CBCT) compared with traditional pre-surgical orthodontics, both quantitatively and qualitatively. METHODS: Two hundred and four anterior teeth from 17 skeletal class III malocclusions were divided into four groups. Groups G1 (upper teeth) and G3 (lower teeth), comprising 120 teeth, accepted traditional pre-surgical orthodontics; groups G2 (upper teeth) and G4(lower teeth), comprising 84 teeth, accepted augmented corticotomy-assisted pre-surgical orthodontics. The changes of alveolar bone dehiscence and fenestration of each tooth in all groups were evaluated with the help of CBCT. RESULTS: Quantitative analysis for comparing both groups: For the upper teeth, d1 - d0 was different between both groups while f1 - f0 was not statistically different. For the lower teeth, d1 - d0 was statistically different between both groups while f1 - f0 was not statistically different. Qualitative analysis: For the teeth that had no dehiscence before treatment, G2 and G4 had a better transition than did G1 and G3. For those having dehiscence before treatment, G4 had a better transition than did G3. For teeth having no fenestration before treatment, there was no statistically significant difference in transition between the control and treatment groups. For those having fenestration before treatment, G4 had a better transition than did G3. CONCLUSIONS: For skeletal class III patients, augmented corticotomy-assisted orthodontic treatment is a promising method of improving alveolar bone dehiscence and fenestration for lower anterior teeth, and it also has the potential to protect both lower and upper anterior teeth against dehiscence.

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Cerebrovascular disease such as stroke is one of the most common diseases in the aging population, and neural stem cells (NSCs) transplantation may provide an alternative therapy for cerebral ischemia. However, a hostile microenvironment in the ischemic brain offers is challenging for the survival of the transplanted cells. Considering the neuroprotective role of basic fibroblast growth factor (bFGF), the present study investigated whether bFGF gene-modified NSCs could improve the neurological function deficit after transient middle cerebral artery occlusion (MCAO) in adult male Sprague-Dawley rats. These rats were intravenously injected with modified NSCs (5×106/200 µL) or vehicle 24 h after MCAO. Histological analysis was performed on days 7 and 28 after tMCAO. The survival, migration, proliferation, and differentiation of the transplanted modified C17.2 cells in the brain were improved. In addition, the intravenous infusion of NSCs and bFGF gene-modified C17.2 cells improved the functional recovery as compared to the control. Furthermore, bFGF promoted the C17.2 cell growth, survival, and differentiation into mature neurons within the infarct region. These data suggested that bFGF gene-modified NSCs have the potential to be a therapeutic agent in brain ischemia.

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INTRODUCTION: The purposes of this study were to evaluate the accuracy of cone-beam computed tomography (CBCT) for detecting naturally occurring alveolar bone dehiscences and fenestrations and to find a better method to diagnose them. METHODS: The sample consisted of 122 anterior teeth in 14 patients with Class III malocclusion who accepted accelerated osteogenic orthodontic surgery in the anterior tooth region. Dehiscences and fenestrations were measured both directly, with a gauge during surgery, and indirectly, by CBCT scans collected before treatment. A Bland-Altman plot for calculating agreement between the 2 methods was used. Direct data were regarded as the gold standard, and indirect data were analyzed to evaluate the accuracy of CBCT for detecting dehiscences and fenestrations by sensitivity, specificity, positive predictive value, negative predictive value, Youden index, positive likelihood ratio, and negative likelihood ratio. Receiver operator characteristic curves were also used to determine the area under curve and the best critical points of CBCT for detecting dehiscences and fenestrations. RESULTS: Both the sensitivity and specificity of CBCT for dehiscences and fenestrations were over 0.7. The negative predictive values were high (dehiscence, 0.82; fenestration, 0.98), whereas the positive predictive values were relatively low (dehiscence, 0.75; fenestration, 0.16). Areas under the curve were 0.873 for dehiscences and 0.766 for fenestrations. The best critical points for detecting both dehiscences and fenestrations were 2.2 mm. CONCLUSIONS: Our study showed that the CBCT method has some diagnostic value for detecting naturally occurring alveolar bone dehiscences and fenestrations. However, this method might overestimate the actual measurements.

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PURPOSE: To quantitatively evaluate lower incisor decompensation and the surrounding periodontal region after augmented corticotomy-assisted surgical orthodontics in patients with Class III malocclusion. MATERIALS AND METHODS: This prospective study enrolled patients with severe Class III malocclusion who underwent augmented corticotomy in the lower anterior region before orthodontic surgery. Cone-beam computed tomograms and lateral cephalograms were obtained before treatment (T0), after presurgical orthodontic treatment (T1), and at removal of the orthodontic surgical appliances (T2). Repeated measures analysis of variance was used to compare variables at each time point: root length (RL), anterior vertical alveolar bone level at the labial side (AVBL), posterior vertical alveolar bone level at the lingual side (PVBL), labial alveolar bone thickness at the apex (LA), lingual alveolar bone thickness at the apex (LP), and angle of the incisor to the mandibular plane (L1-MP). RESULTS: In the 8 subjects studied, RL was maintained from T0 to T2 (P > .05), whereas AVBL and PVBL increased from T0 to T1 (P < .05) and then decreased from T1 to T2 (P < .05). LA and L1-MP increased from T0 to T1 (P < .001) but remained steady from T1 to T2 (P > .05). LP decreased from T0 to T1 (P < .05) but increased from T1 to T2 (P < .05) with no further change. CONCLUSIONS: Augmented corticotomy-assisted surgical orthodontics can achieve adequate tooth decompensation with minimal periodontal side-effects in the lower anterior region in patients with Class III malocclusion.

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PURPOSE: To investigate the prevalence and distribution of alveolar bone dehiscence and fenestration in anterior region of skeletal Class III malocclusions. METHODS: The sample consisted of 19 males and 25 females with skeletal Class III malocclusions selected from consecutive patients of Department of Oral and Cranio maxillofacial Science from May 1st to June 1st, 2012. Five hundred and twenty-three teeth were examined by cone-beam CT (CBCT) in total while alveolar bone dehiscences and fenestrations were detected and measured using a new method. The data was processed using SAS8.02 software package. RESULTS: The prevalence of dehiscence was 61.57% in all teeth, while fenestration was 31.93% and the prevalence of defect (dehiscence or fenestration) was 77.44%. More defects were found in the mandible (58.52%) especially. The tooth site which was most commonly affected was lower canine, while the least was upper central incisor. No significant difference was found between both genders on most tooth sites of anterior region but more defects was found in lower central incisor and lower lateral incisor in male subjects. CONCLUSIONS: Alveolar defect is an extremely common finding in this sample. Whether alveolar defects such as dehiscence and fenestration are potential factors of root resorption and addition bone loss is still unclear, and further researches are needed.

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PURPOSE: To investigate the changes of periodontal conditions after micro-osteotomy assisted lower incisor decompensation for skeletal Class III malocclusions with alveolar hypoplasia in the lower anterior region. METHODS: The sample consisted of 22 cases diagnosed as skeletal Class III malocclusions with alveolar hypoplasia in the lower anterior region, selected from consecutive patients of Department of Oral & Cranio-maxillofacial Science of Shanghai Ninth People's Hospital during 2009-2012. The samples were divided into 2 groups; G1 comprised 10 patients who accepted micro-osteotomy assisted lower incisor decompensation; G2 comprised 12 patients who chose traditional pre-surgical decomposition. The changes of periodontal conditions of both groups were evaluated with the help of cone-beam CT(CBCT). Data was processed using SAS8.02 software package. RESULTS: For subjects in G1, during the micro-osteotomy assisted pre-surgical orthodontics, no significant difference was found in the amount of root resorption of lower incisors.But labial and lingual vertical alveolar bone loss were 2.60 mm and 2.22 mm; alveolar bone thickness increased by 3.05 mm on the labial side and decreased by 0.88 mm on the lingual side (P<0.05). Better periodontal conditions were reserved compared with those of G2. CONCLUSIONS: Micro-osteotomy assisted pre-surgical orthodontics was much safer than traditional orthodontics for skeletal Class III malocclusions with alveolar hypoplasia in the lower anterior region.

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