Stem cells are a class of undifferentiated cells with high self-renewal and rapid proliferative capabilities. Undercertain conditions, stem cells can induce differentiation into other tissue cells of the human body, such as skeletal muscle cells, cardiomyocytes, osteoblasts, and nerve-like cells. In recent years, with the development of tissue engineering and regenerative medicine, stem cells have been extensively used in various fields of regenerative medicine as optimal seeded cells; however, there are still some problems, such as the decreased cell survival rate and regenerative capacity after transplantation, immune rejection, and ethical supervision. Therefore, it is difficult to universally and safely use stem cell banks for regeneration applications. The paracrine effect of stem cells has been extensively studied since its discovery. Increasing evidence supports the view that stem cells act in paracrine manner, and the secretion of exosomes plays a vital role in their biological functions. Exosomes are nanoscale extracellular vesicles containing biologically active molecules such as RNA and proteins; they possess similar functions to stem cells and play important roles in cell communication, immune response, and repair of tissue damage. At present, clinical studies on stem cell exosomes in tissue engineering and regenerative medicine have also been carried out in the fields of bone and cartilage repair, nerve tissue regeneration, liver tissue regeneration, skeletal muscle tissue engineering, vascular regeneration, taste bud repair, tooth regeneration, etc. In this paper, the composition, formation, release and identification of exosomes are introduced in detail. The research status of exosomes from different stem cell sources in tissue engineering and regenerative medicine is described, and their broad application prospects are discussed.
Temporomandibular joint disorder (TMD) is a common clinical disease in stomatology that occurs frequently in young people, mostly in women, with an incidence of approximately 30%; its clinical manifestations include mandibular dysfunction, regional pain, and clicking noises around the temporomandibular joint (TMJ). Some patients have tinnitus, headache and other symptoms. With regard to the treatment procedures of TMD, a gradient sequential treatment model is currently preferred, each of which has strict indications. Generally, conservative treatment or noninvasive treatment is preferred and is suitable for patients with dysfunction or mild organic disease. The second-choice minimally invasive treatment is suitable for patients who have failed conservative treatment or patients with mild organic disease. Finally, open surgery, which is suitable for patients who are not responsive to the first two treatments and show severe organic lesions, can be considered. The formulation of an open surgery treatment diagnosis and treatment plan should be personalized, led by doctors, and completed with the cooperation of patients. This article describes the “gradient sequential treatment” of temporomandibular joint disorders.
Objective To investigate the role of the bone morphogenetic protein 2 (BMP2)-Smad1/5 and p38MAPK signaling pathways in the osteogenic differentiation of MSMSCs by insulin-like growth factor 1 (IGF1).Methods A recombinant adenovirus (RAD) and IGF1 expressing IGF1 gene were constructed. After osteogenic induction, qRT-PCR and Western blot were used to detect the phosphorylation level of Smad1/5 and the expression of the BMP-2 protein in the BMP-Smad signaling pathway; immunohistochemistry was used to observe the nuclear translocation of Smad1/5; qRT-PCR and Western blot were used to detect IGF with Noggin and SB203580, inhibitors of the p38MAPK signaling pathway 1-mediated osteogenic differentiation of MSMSCs.Results The recombinant IGF1 adenovirus was constructed successfully. MSMSCs were cultured in inductive medium after infection with different concentrations of Ad-IGF1, and then, the protein levels of BMP2 and p-Smad1/5 increased. IGF1 can also induce nuclear translocation of Smad1/5. In addition, Noggin significantly reduced the phosphorylation level of Smad1/5 and the formation of mineralized nodules in the MSMSCs. The mRNA levels of Runx2, OPN and ALP also decreased. In contrast, SB203580 decreased neither the phosphorylation level of p38 nor the mRNA expression of Runx2, OPN and ALP in the Ad-IGF1 MSMSCs.Conclusion IGF1 can promote the osteogenic differentiation of MSMSCs via the BMP2-Smad1/5 signaling pathway. In contrast, IGF1 may not promote the osteogenic differentiation of MSMSCs via the p38MAPK signaling pathway.
Objective To explore the effect of 1,25(OH)2D3 on the regulation of bone metabolism in a high-glucose environment and to provide evidence for the possible regulatory mechanism of 1,25(OH)2D3 on osteoblasts in a high-glucose environment.Methods The osteoblast cell line MC3T3-E1 was cultured in 3 groups: ① control group, cultured in low-glucose (5.5 mmol/L) DMEM; ② high-glucose group: cultured in high-glucose (22 mmol/L) DMEM; ③ high-glucose +1,25(OH)2D3 group: high-glucose DMEM + 1,25(OH)2D3 medium culture. The CCK-8 method was used to detect cell proliferation in each group; Annexin V and FITC apoptosis kits were used to detect apoptosis; Alizarin red was used to semiquantitatively analyze cell differentiation; qRT-PCR was used to detect forkhead transcription factor-1 (forkhead transcription factor 1, FoxO1) mRNA expression. Immunofluorescence was used to observe the changes in FoxO1 protein expression and its relative position in the nucleus.Results Our analysis showed that compared with those in the control group, the osteoblast apoptosis and proliferation in the high-glucose group were improved, while differentiation was inhibited (P < 0.05); at the same time, the mRNA expression of FoxO1(P = 0.006) was reduced. The immunofluorescence results showed that more FoxO1 was inside the nucleus (P < 0.001). Compared with those in the high-glucose group, excessive proliferation was inhibited, apoptosis was reduced, and osteogenic differentiation was improved in the high-glucose +1,25(OH)2D3 group (P < 0.05); furthermore, FoxO1 mRNA was decreased (P = 0.006), and the transfer of FoxO1 protein was blocked (P < 0.001).Conclusion We found that 1,25(OH)2D3 may prevent the transfer of FoxO1 to the cell nucleus, inhibit the abnormal proliferation and apoptosis of osteoblasts in a high-glucose environment, and reverse the inhibitory effect of high glucose on the differentiation of osteoblasts.
Objective To provide a clinical reference by evaluating the precision of virtual surgical planning in two-jaw orthognathic surgery.Methods Thirty consecutive patients who required two-jaw orthognathic surgery were included. A composite skull model was reconstructed using data from spiral computed tomography scan and surface scanning of the dental arch. LeFort I osteotomy of the maxilla and bilateral sagittal split ramus osteotomy of the mandible were simulated using Dolphin Imaging 11.7 Premium. Genioplasty was performed if indicated. Virtual plan was then transferred to operation room using 3D-printed surgical templates. Frankfort horizontal plane (FHP), midfacial plane (perpendicular to the FHP through the nasion), and coronal plane (perpendicular to the FHP through the sella point) were the selected three symmetry planes.Midpoint of the contact of the maxillary and mandibular central incisors (UI, LI), and the mesio-buccal cusp of the first maxillary and mandibular molars (U6-R,U6-L, L6-R, L6-L) were the six chosen volumetric landmarks. To calculate the linear difference and overall mean linear difference (mean difference of the distance between UI, LI, U6-R, U6-L, L6-R, L6-L to FHP, midfacial and coronal plane) between simulated and postoperative models, the distance between selected landmarks and symmetry planes was measured. To calculate the angular difference and overall mean angular difference, values of the angles constructed by the occlusal, palatal, and mandibular plane to FHP and midfacial plane respectively were determined on simulated and postoperative models.Results The virtual surgical planning was successfully transferred to actual surgery with the help of 3D-printed surgical templates. All patients were satisfied with the postoperative facial profile and occlusion. The overall mean linear difference was 0.81 mm (0.71 mm for maxilla and 0.91 mm for mandible); and the overall mean angular difference was 0.95° (the mean angular difference relative to FHP was 1.10°, and that relative to midfacial plane was 0.83°).Conclusion Virtual surgical planning facilitated the diagnosis, treatment planning, and precise bony segments repositioning in two-jaw orthognathic surgery.
Objective To study the efficacy and safety of oral mucoadhesive containing chitosan for the treatment of recurrent aphothous stomatitis (RAS).Methods 72 subjects, who were diagnosed with RAS, were involved in the study. The subjects were randomly allocated to the test or control group and shown how to use the films. The film containing chitosan was provided to the participants in the test group and the polyvinyl alcohol film was provided to the control group. Baseline, pain score (visual analog scale), ulcer size and adverse effects were recorded.Results The reduction in ulcer size was significantly greater (P < 0.05) in the treatment group (2.91 ± 3.66)mm 2 than in the control group (1.10 ± 2.26) mm 2 between days 4 and 6. There was no significant difference between the treatment and control groups in the pain score, ulcer size, or reduction in the pain score (P > 0.05). No obvious adverse effects were observed. Conclusion The oral mucoadhesive film containing chitosan promotes healing of RAS.
Objective To compare the measurement accuracy of two-dimensional (2D) photography and three-dimensional (3D) photography in the analysis of the asymmetric appearance of children with cleft lip and palate and the influence of the severity of asymmetric deformity on the accuracy of facial measurement to guide clinical measurement work.Methods Children with unilateral cleft lip were enrolled in this prospective study. Seven parameters--the deviation of the pronasale, subnasale, and labrale superius, as well as the cleft/noncleft ratio of the width of nostrils, length and height of lateral lips and height of columella-were measured with Vernier calipers as the gold standard. Traditional 2D photography and 3D stereophotogrammetry photos were taken and measured. The extent of cleft malformation is indicated by the ratio of the cleft side to the noncleft side. The error size is represented by the ratio difference between two-dimensional photography or stereophotogrammetry with the ratio of the gold standard.Results Thirteen patients were eventually recruited. The measurement results of the ratio of lateral lip height by 2D photography tended to be larger (P=0.019), and the measurement results of the ratio of columella height tended to be smaller (P=0.008). The measurement results of the deviation of the subnasale by stereophotogrammetry tended to be smaller (P=0.003). The pronasale deviation (P=0.022) with two-dimensional photography, the deviation of the labrale superius (P=0.025) and the ratio of lateral lip length (P=0.036) with stereophotogrammetry had a significant negative correlation with the extent of cleft malformation.Conclusion Both two-dimensional photography and stereophotogrammetry have errors and biases that underexaggerate or overexaggerate the extent of cleft malformation, and some errors may increase with the decrease in the extent of cleft malformation. When applying two-dimensional and three-dimensional photography to analyze cleft lip and palate deformities, these biases should be considered to evaluate the face more objectively.
Objective To explore the relationship between MSX1 gene detection and tooth loss in a Van der Woude syndrome (VWS) family.Methods DNA was extracted from the venous blood of 2 patients with dental hypodontia in the 9th family of Van der Woude syndrome (VWS) families and 62 controls with complete dentition. Primers were designed for the MSXl gene. The coding regions of exons 1 and 2 of the MSX1 gene were amplified by PCR. The purified products of exons 1 and 2 of the MSX1 gene were sequenced and analyzed by sequence alignment.Results The ivs2+68 C>T polymorphism in the MSX1 gene was found in the VWS9 members with tooth loss, and the VWS patients with IRF6 gene mutations had increased tooth loss.Conclusion Congenital tooth loss in the patients with congenital missing teeth in VWS family 9 may be related to the ivs2 + 68 C> T polymorphism of the MSX1 gene.
Three dimensionally printed composite porous bone tissue engineering scaffolds have become a research focus. Composite polyvinyl alcohol (PVA) has good biocompatibilityand degradability, but it cannot be prepared independently because it cannot resist highmechanical resistance. This material shows many advantages, such as good biocompatibility, degradability and mechanical properties, when compounded with other materials with good mechanical properties and good biocompatibility. Therefore, 3D printed composite PVA scaffold material can optimize the performance of PVA scaffolds. This article reviews 3D printing bone scaffold technology, polyvinyl alcohol (PVA), and composite PVA scaffolds for in vivo and in vitro bone formation.
IgG4-related sialadenitis (IgG4-RS) is a type of autoimmune disease that has been recognized in recent years, and the pathogenesis remains unclear. IgG4-RS mainly affects the submandibular gland and parotid gland and is characterized by diffuse painless swelling of the bilateral salivary glands and/or lacrimal glands, usually lasting more than 3 months. Some patients have accompanying hearing loss or hearing impairment, sinusitis, lymphadenopathy and other symptoms; nearly half of patients have different degrees of salivary gland secretion disorders. Most patients have elevated serum IgG4 levels, but they cannot be used as the only marker for diagnosis. Histopathology remains the “gold standard” for diagnosis. Presently, submandibular gland biopsy is often used for diagnosis. Histopathology showed lymphoplasmacytic infiltration, occlusive phlebitis, striated fibrosis; immunohistochemistry showed IgG4 +/IgG +plasma cells >40%, and IgG4 + plasma cell/high-power field vision > 10. Glucocorticoids are regarded as first-line drugs for the treatment of this disease. Clinically, glucocorticoids are often combined with immunosuppressive agents such as cyclophosphamide, but no standard drug regimen exists. Most patients have a significant short-term treatment effect, and the long-term prognosis requires further study. Patients with a recurrence tendency should adjust the hormone dose over time. In the future, further research is needed regarding the pathogenesis and treatment of the disease to improve the clinical diagnosis rate and therapeutic effect.
As acute enterovirus-induced infections, herpangina(HA) and hand-foot-mouth disease(HFMD) are similar in many aspects. Although these diseases vary with time and region, many studies have shown that the viruses causing HA and HFMD are consistent, and there is no notable difference in partial VP1 gene sequences between different viruses. HA and HFMD also resemble each other in epidemiological features. Both infections show significant summertime seasonality, have a strong connection with certain environmental conditions and are most prevalent in young children and infants. Herpangina is thought to be a mild disease, defined as vesicular enanthem and then ulcers of the fauces and soft palate with presentation of fever, sore throat, and decreased appetite. HFMD, which could lead to severe symptoms, is also characterized by oral ulcers, although they are chiefly on the buccal mucosa and tongue, and typical vesicular rashes, which are most commonly found on the hands, feet, knees and buttocks. While HA is generally believed to be self-limited and has a favorable prognosis, HA with certain clinical characteristics, such as diarrhea, vomiting, limb jitter and sleepiness, can evolve into HFMD, according to some literature in recent years. However, HA is an independent risk factor for HFMD, and severe cases only present with herpes appearing at the isthmus of the fauces at an early stage, which indicates a strong correlation between them. Clinical manifestations of HA should be considered by medical staff to identify potential children with HFMD as early as possible to prevent its further development or transformation.
Erbium, chromium： yttrium scandium gallium garnet （Er, Cr： YSGG） laser is mainly used for root canal treatment, periodontal disease, tooth decay, dentin hypersensitivity, pulp amputation, etc in the field of dentistry. This paper mainly describes the research progress of Er, Cr： YSGG laser in root canal therapy from following four aspects： root canal sealing, sterilization, cavitation effect and the effect on periapical tissue. The experimental results showed that when the operation parameters of Er, Cr： YSGG were 2 ~ 4 w and 20 Hz, it could effectively remove the stained layer of dentin tubules and improve the tightness between materials and dentin. The thermal effect produced by Er, Cr： YSGG energy has a sterilizing effect, while the optical conductivity of the tooth enables the rinse solution to enter deeper tissues, further improving the sterilizing effect. Er, Cr： YSGG also has a cavitation effect, which destroys the surface tension of the deep solution, removing the stain layer and bacteria in the deep layer. However, with the same operation parameters, if Er, Cr： YSGG is not used properly, the thermal effect of Er, Cr： YSGG will cause some damage to the periapical tissues. Therefore, reasonable use time of Er, Cr： YSGG and water cooling conditions are important.
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