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Temporomandibular disorder (TMD) remained a huge clinical challenge, with high prevalence but limited, unstable, and only palliative therapeutic methods available. As one of the most vulnerable sites implicated in TMD, the temporomandibular joint disc (TMJD) displayed a complicated microstructure, region-specific fibrocartilaginous distribution, and poor regenerative property, which all further hindered its functional regeneration. To address the problem, with versatile and relatively simple electrospinning (ELS) technique, our study successfully fabricated a biomimetic, three-dimensional poly (ϵ-caprolactone) (PCL)/polylactide (PLA)/carbon nanotubes (CNTs) disc scaffold, whose biconcave gross anatomy and regionally anisotropic microstructure recapitulating those of the native disc. As in vitro results validated the superior mechanical, bioactive, and regenerative properties of the biomimetic scaffolds with optimal CNTs reinforcement, we further performed in vivo experiments. After verifying its biocompatibility and ectopic fibrochondrogenicity in nude mice subcutaneous implantation models, the scaffolds guided disc regeneration and subchondral bone protection were also confirmed orthotopically in rabbits TMJD defected areas, implying the pivotal role of morphological cues in contact-guided tissue regeneration. In conclusion, our work represents a significant advancement in complex, inhomogeneous tissue engineering, providing promising clinical solutions to intractable TMD ailments. STATEMENT OF SIGNIFICANCE: Complex tissue regeneration remains a huge scientific and clinical challenge. Although frequently implicated in temporomandibular joint disorder (TMD), functional regeneration of injured temporomandibular joint disc (TMJD) is extremely hard to achieve, mainly because of the complex anatomy and microstructure with regionally variant, anisotropic fiber alignments in the native disc. In this study, we developed the biomimetic electrospun scaffold with optimal CNTs reinforcement and regionally anisotropic fiber orientations. The excellent mechanical and bioactive properties were confirmed both in vitro and in vivo, effectively promoting defected discs regeneration in rabbits. Besides demonstrating the crucial role of morphological biomimicry in tissue engineering, our work also presents a feasible clinical solution for complex tissue regeneration.

Background: Scissor bites have been reported in relatively few epidemiological studies because of their extremely low prevalence rate (below 1%). The etiology of scissor bites remains obscure, but its impact on growth and function should not be ignored. Methods: In this case report, a novel treatment that utilizes Invisalign aligners was performed on a 3-year-old child who presented with a bilateral posterior scissor bite and anterior crossbite, accompanied by multisite obstruction in the upper airway. The aligners functioned as occlusion pads to unlock the scissor bite relationship and combined with cross-traction to narrow the maxillary arch and enlarge the mandibular arch simultaneously. Results: The duration of orthodontic therapy was 28 weeks. A multidisciplinary consultation (orthodontics department, ENT department, and spinal surgery) was conducted and a stable result was achieved. A healthy occlusal relationship, improved dental esthetics and a better lateral profile were eventually obtained. Conclusions: Positive treatment outcomes rely on patients’ good compliance in this case. In addition, we hope that clinicians will consider our situation in terms of alternative treatments and interprofessional experience.

Actinomycete strain YIM PH20352, isolated from the rhizosphere soil sample of Panax notoginseng collected in WenShang, Yunnan Province, China, exhibited antifungal activity against some phytopathogenic fungi. The structures of bioactive molecules, isolated from the ethyl acetate extract of the fermentation broth of the strain, were identified as rabelomycin (1) and dehydrorabelomycin (2) based on extensive spectroscopic analyses. Compound 1 exhibited antifungal activity against four tested root-rot pathogens of the Panax notoginseng including Plectosphaerella cucumerina, Alternaria panax, Fusarium oxysporum, and Fusarium solani with the MIC values at 32, 64, 128, and 128 μg/mL, respectively. Compound 2 exhibited antifungal activity against F. oxysporum, P. cucumerina, F. solani, and A. panax with the MIC values at 64, 64, 128, and 128 μg/mL, respectively. Based on the phylogenetic analyses, the closest phylogenetic relative of strain YIM PH20352 is Streptomyces cellulosae NBRC 13027

Repairing bone defect by recapitulation of endochondral bone formation, known as developmental engineering, has been a promising approach in bone tissue engineering. The critical issue in this area is how to effectively construct the hypertrophic cartilaginous template in vitro and enhance in vivo endochondral ossification process after implantation. Pulsed ultrasound stimulation has been widely used in the clinic for accelerating bone healing in fractures and nonunions. The aim of this study was to investigate whether ultrasound (US) could accelerate in vitro chondrogenesis and the hypertrophic process in certain microenvironments. Rat bone marrow mesenchymal stem cells were chondrogenic or hypertrophic differentiated in a three-dimensional pellet culture system with different media, and treated with different intensities of US. US exposure promoted chondrogenic differentiation of stem cells and inhibited their transition into the hypertrophic stage in a chondrogenic-friendly microenvironment. US significantly advanced hypertrophic differentiation of bone marrow stem cell pellets in hypertrophic medium after chondrogenesis. Our data indicated that pulsed US promoted in vitro chondrogenic and hypertrophic differentiation of stem cell pellets in specific culture conditions. The present study proves the potential application of US in the in vitro stage of "developmental engineering" for bone development and repair.

Purpose During orthodontic treatment and chronic periodontitis, the periodontal vasculature is severely impaired by overloaded mechanical force or chronic inflammation. This leads to the hypoxic milieu of the periodontal stem cell niche and ultimately affects periodontal tissue remodelling. However, the role of hypoxia in the regulation of periodontal ligament stem cell (PDLSC) behaviours still remains to be elucidated. The present study was aimed at investigating the effects of hypoxia on osteogenic differentiation, mineralisation and paracrine release of PDLSCs and further demonstrating the involvement of mitogen-activated protein kinase (MAPK) signalling in the process. Methods First, PDLSCs were isolated and characterised. Second, the effects of different periods of hypoxia on PDLSC osteogenic potential, mineralisation and paracrine release were investigated. Third, extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 kinase activities under hypoxia were measured. Finally, specific MAPK inhibitors PD98059 and SB203580 were employed to investigate the involvement of two kinases in PDLSC osteogenesis under hypoxia. Results Immunocytochemical staining and multilineage differentiation assays verified that the isolated cells were PDLSCs. Cell viability, alkaline phosphatase (ALP) activity, messenger RNA (mRNA) and protein levels of runt-related transcription factor 2 (Runx2) and Sp7, mineralisation and prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) release were significantly increased by hypoxia. ERK1/2 and p38 were activated in different ways under hypoxia. Furthermore, hypoxia-stimulated transcription and expression of the above-mentioned osteogenic regulators were also reversed by PD98059 and SB203580 to different degrees. Conclusions Exposure of PDLSCs to hypoxia affected their osteogenic potential, mineralisation and paracrine release, and the process involved mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) and p38 MAPK signalling.

Purpose: The purpose of this study was to evaluate the various factors that influence the success rate of miniscrew implants used as orthodontic anchorage. Materials and Methods: Potential confounding variables examined were sex, age, vertical (FMA) and sagittal (ANB) skeletal facial pattern, site of placement (labial and buccal, palatal, and retromandibular triangle), arch of placement (maxilla and mandible), placement soft tissue type, oral hygiene, diameter and length of miniscrew implants, insertion method (predrilled or drill-free), angle of placement, onset and strength of force application, and clinical purpose. The correlations between success rate and overall variables were investigated by logistic regression analysis, and the effect of each variable on the success rate was utilized by variance analysis. Results: One hundred fourteen patients were included with a total of 253 miniscrew implants. The overall success rate was 88.54% with an average loading period of 9.5 months in successful cases. Age, oral hygiene, vertical skeletal facial pattern (FMA), and general placement sites (maxillary and mandibular) presented significant differences in success rates both by logistic regression analysis and variance analysis (P < .05). Conclusion: To minimize the failure of miniscrew implants, proper oral hygiene instruction and effective supervision should be given for patients, especially young (< 12 years) high-angle patients with miniscrew implants placed in the mandible.

The periodontal ligament (PDL) is a group of highly aligned and organized connective tissue fibers that intervenes between the root surface and the alveolar bone. The unique architecture is essential for the specific physiological functionalities of periodontium. The regeneration of periodontium has been extensively studied by researchers, but very few of them pay attention to the alignment of PDL fibers as well as its functionalities. In this study, we fabricated a three-dimensional multilayered scaffold by embedding highly aligned biodegradable poly (e-caprolactone)-poly(ethylene glycol) (PCE) copolymer electrospun nanofibrous mats into porous chitosan (CHI) to provide topographic cues and guide the oriented regeneration of periodontal tissue. In vitro , compared with random group and porous control, aligned nanofibers embedded scaffold could guide oriented arrangement and elongation of cells with promoted infiltration, viability and increased periodontal ligament-related genes expression. In vivo , aligned nanofibers embedded scaffold showed more organized arrangement of regenerated PDL nearly perpendicular against the root surface with more extensive formation of mature collagen fibers than random group and porous control. Moreover, higher expression level of periostin and more significant formation of tooth-supporting mineralized tissue were presented in the regenerated periodontium of aligned scaffold group. Incorporation of aligned PCE nanofibers into porous CHI proved to be applicable for oriented regeneration of periodontium, which might be further utilized in regeneration of a wide variety of human tissues with a specialized direction. Statement of Significance The regeneration of periodontium has been extensively studied by researchers, but very few of them give attention to the alignment of periodontal ligament (PDL) fibers as well as its functionalities. The key issue is to provide guidance to the orientation of cells with aligned arrangement of collagen fibers perpendicular against the root surface. This study aimed to promote oriented regeneration of periodontium by structural mimicking of scaffolds. The in vitro and in vivo performances of the scaffolds were further evaluated to test the topographic-guiding and periodontium healing potentials. We also think our research may provide ideas in regeneration of a wide variety of human tissues with a specialized direction.

A Ralstonia sp. strain JC-64 that is capable of accumulating poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P[3HB-co-3HV]) from cottonseed oil and valeric acid was isolated. By using a high limiting-nitrogen (HLN) mineral medium as the medium for the second stage of the fermentation process and by adding the two carbon sources at different times, a range of copolymers with 12–62 mol% of 3HV were produced from a series of HLN mineral mediums containing different compositions of cottonseed oil and valeric acid by Ralstonia sp. JC-64. The melting temperature (T m ) of polyhydroxybutyrate from cottonseed oil was 174°C and that of P(3HB-co-3HV) with the highest 3HV-mol fraction (62%) was 81°C.

Objective We recently reported establishment of a periodontal ligament (PDL) tissue model, which may mimic the biological behaviour of human PDL under static compression in orthodontic tooth movement (OTM). In the present study, we aimed at investigating the time-course gene expression profiles of the PDL tissue model under compression. Design The PDL tissue model was established through 3-D-culturing human PDL cells (PDLCs) in a thin sheet of porous poly lactic-co-glycolic acid (PLGA) scaffolds, which was subjected to 25 g/cm2 static compression for 6, 24 and 72 h respectively. After that, its gene expression profiles were investigated using microarray assay, followed by signalling pathway and gene ontology (GO) analysis. Real-time RT-PCR verification was done for 15 identified genes of interest. The cell proliferation alteration was detected through EdU labelling. Results (1) Among the genes identified as differentially expressed, there were numerous osteoclastogenesis inducers (including CCL20, COX-1, COX-2, RANKL, PTHrP, IL-11, IL-8, etc.), osteoclastogenesis inhibitors (including IL-1Ra, NOG, OPG, etc.), and other potential bone remodelling regulators (including STC1, CYR61, FOS, etc.). (2) According to analysis of the microarray data, the most significant pathways included Cytokine–cytokine receptor interaction (containing CCL20, RANKL, IL-11, IL-8, etc.), MAPK (containing FGF7, FOS, MAP3K8, JUN, etc.) and Cell cycle (containing CDK1, CCNA2, etc.); the most significant GOs included Cell–cell signalling (containing CCL20, STC1, FGF7, PTHrP, IL-11, IL-8, etc.), Extracellular space (containing CCL20, IL-1Ra, NOG, PTHrP, IL-11, IL-8, etc.) and Microtubule-based movement (containing KIF11, KIF23, etc.). (3) After prolonged compression, cell proliferation was significantly inhibited. Conclusion The present findings have expanded our understandings to the roles that PDL plays under static compression in OTM.

Objectives . The aim of this study was to provide an anatomical map for micro-screw placement in a safe location between the posterior dental roots of the beagle jaw. Study design . Three dimensional (3D) reconstructed images of 12 adult male beagles and jaw ground sections of another 6 beagles were examined. We measured sagittal, vertical and horizontal parameters in the intraradicular and interradicular regions of posterior teeth. Results . The data showed that the safe zones were located in the intraradicular spaces of P2, P3, P4, M1, M2 and the interradicular spaces between P4 and M1, M1 and M2 in the mandible; in the maxilla, they were located in the intraradicular spaces of P3, P2, M1 and the interradicular space between P3 and M1. Conclusions . The present study provides a map of safe areas for the application of micro-screws in beagles.