Comparison of outcomes and characteristics of patients admitted to the ICU with COVID-19 and other community-acquired pneumonia based on propensity score matching.

OBJECTIVE: To compare the similarities and differences between patients with Coronavirus Disease 2019 (COVID-19) and those with other community-acquired pneumonia (CAP) admitted to the intensive care unit (ICU), utilizing propensity score matching (PSM), regarding hospitalization expenses, treatment options, and prognostic outcomes, aiming to inform the diagnosis and treatment of COVID-19. METHODS: Patients admitted to the ICU of the Third People's Hospital of Datong City, diagnosed with COVID-19 from December 2022 to February 2023, constituted the observation group, while those with other CAP admitted from January to November 2022 formed the control group. Basic information, clinical data at admission, and time from symptom onset to admission were matched using PSM. RESULTS: A total of 70 patients were included in the COVID-19 group and 119 in the CAP group. The patients were matched by the propensity matching method, and 37 patients were included in each of the last two groups. After matching, COVID-19 had a higher failure rate than CAP, but the difference was not statistically significant (73% vs. 51%, p = 0.055). The utilization rate of antiviral drugs (40% vs. 11%, p = 0.003), γ-globulin (19% vs. 0%, p = 0.011) and prone position ventilation (PPV) (27% vs. 0%, p < 0.001) in patients with COVID-19 were higher than those in the CAP, and the differences were statistically significant. The total hospitalization cost of COVID-19 patients was lower than that of CAP patients, and the difference was statistically significant (27889.5 vs. 50175.9, p = 0.007). The hospital stay for COVID-19 patients was shorter than for CAP patients, but the difference was not statistically significant (10.9 vs. 16.6, p = 0.071). CONCLUSION: Our findings suggest that limited medical resources influenced patient outcomes during the COVID-19 pandemic. Addressing substantial demands for ICU capacity and medications during this period could have potentially reduced the mortality rate among COVID-19 patients.

The effects of dehiscence and fenestration before orthodontic treatment on external apical root resorption in maxillary incisors.

INTRODUCTION: The objective of this study was to investigate the effects of dehiscence and fenestration on external apical root resorption (EARR) in maxillary incisors. METHODS: Seventy-eight patients were selected for this study. We set dehiscence, fenestration, sex, extraction, or nonextraction, tooth position, initial age, and duration of treatment as independent variables and EARR as the dependent variable. General statistical descriptions for these variables were made by mean, standard deviation and occurrence rates, etc. To make the data visualization and find more information, 2 heat maps were made. Generalized estimation equation analysis was performed to determine associations between EARR and independent variables. RESULTS: The occurrence rates of dehiscence and fenestration in maxillary incisors were 14.77% and 10.74%, respectively. The average value of EARR was 1.09 ± 0.87 mm in this study. Dehiscence, tooth position, extraction, initial age, and duration had significant correlations with EARR. The ratio of exponent B was 1:1.643 for dehiscence and nondehiscence, whereas fenestration and sex had no significant association with EARR. CONCLUSIONS: The amount of EARR at maxillary incisors in patients with dehiscence before orthodontic treatment might be less than that in patients without it, and different incisors might have different contributions to it. However, the low value of exponent B for dehiscence meant that there might be other unknown factors that were involved in this study.

Evaluation of palatal support tissues for placement of orthodontic mini-implants in mouth breathers with high-narrow palates versus nose breathers with normal palates: a retrospective study.

OBJECTIVES: The aim of this study was to compare the palatal total support tissues (TSTs) and bone support tissues (BSTs) at 5-mm paramedian section to the midsagittal suture between mouth breathers with high-narrow palates and nose breathers with normal palates and confirm the practicability and limitation on superimposition of lateral cephalograms and plaster models for orthodontic mini-implant (OMI) implantation in these patients. MATERIAL AND METHODS: The sample consisted of 27 mouth breathers with high-narrow palates (study group (SG)) and 27 nose breathers with normal palates (control group (CG)). Upper digital dental models were superimposed with corresponding cone beam computed tomography (CBCT) images; then, TSTs and BSTs vertical to the curvature of the palatal mucosa were measured on the 5-mm paramedian section to the midsagittal suture. The measuring sites were the third ruga (R) and the sites anterior and posterior to R at 2-mm interval (A2, A4, A6, and A8; P2, P4, P6, and P8) along the palatal mucosa outline. TSTs and BSTs were also measured on the superimposition of lateral cephalograms and plaster models, and the site with the largest TST value in each patient was recorded. Descriptive statistics, independent-samples t test, and hierarchical clustering heat map were used for statistical analysis. RESULTS: The greatest average values of TSTs and BSTs in SG were 12.24 ± 2.63 mm and 9.59 ± 2.36 mm at P2 site, and those in CG were 12.96 ± 2.39 mm and 10.56 ± 2.38 mm at R site, respectively. The average values of both TSTs and BSTs in SG were less than those in CG at all insertion sites. Significant differences (P < 0.05) were found at A4, A6, and R for TSTs and at R and P4 for BSTs. P2 and R were clustered together for both TSTs and BSTs by the cluster analysis on heat map in both SG and CG. In both groups, only one patient from SG was found to have the insertion site with the largest TST value on 2D superimposition located in the blue area on the heat map, where the measurement values of TSTs were less than 8.5 mm and those of BSTs were less than 5 mm. CONCLUSIONS: Mouth breathers with high-narrow palates may have less palatal support tissues than nose breathers with normal palates at 5-mm paramedian section to the midsagittal suture of palate. The site a little posterior to R is more suitable for OMI implantation in mouth breathers. Two-dimensional superimposition of lateral cephalograms and plaster models can provide relatively effective assessment for the site choice of OMI implantation in both mouth breathers with high-narrow palates and nose breathers with normal palates. CLINICAL RELEVANCE: Three-dimensional superimposition of CBCT data and digital dental model can provide accurate information for palatal OMI implantation. Meanwhile, 2D superimposition of lateral cephalograms and plaster models can be used for assessing the implantation sites at 5-mm paramedian section to the midsagittal suture of palates in mouth breathers under most conditions even those who have less palatal support tissues.

[Evaluation of dental and craniofacial characteristics in patients with mild skeletal facial asymmetry].

PURPOSE: The purpose of this study was to investigate the dental and craniofacial morphological characteristics in patients with mild skeletal facial asymmetry, and to investigate the relationship between mild skeletal facial asymmetry and dental anomalies. METHODS: Thirty patients with mild skeletal facial asymmetry (experimental group) and 30 patients with normal faces (control group) were selected. All patients were scanned by cone-beam computed tomography (CBCT) and X-ray machine, Winceph software was used to measure the posteroanterior cephalometric radiographs, NNT software was used to measure the CBCT data. The results were analyzed by Chi-square test, paired t test and independent sample t test using SPSS 19.0 software package. RESULTS: There were significant differences between the left and right sides of faces, teeth and alveolar bone of the first molar in the experimental group. The angle of mandibular dental midline and facial midline, the inclination of the frontal mandibular plane, the inclination of the first molar, the inclination of alveolar bone of the mandibular first molar, the width of alveolar bone of the mandibular first molar showed significant differences between the experimental group and the control group (P<0.05). There are some correlations among menton deviation, inclination of the first molar and alveolar bone of the first molar. CONCLUSIONS: Patients with mild skeletal facial asymmetry showed some specific skeletal and dental characteristics. There could be some correlations between these features．.

Daughters of the Enamel Organ: Development, Fate, and Function of the Stratum Intermedium, Stellate Reticulum, and Outer Enamel Epithelium.

The tooth enamel organ (EO) is a complex epithelial cell assembly involved in multiple aspects of tooth development, including amelogenesis. The present study focuses on the role of the nonameloblast layers of the EO, the stratum intermedium, the stellate reticulum, and the outer enamel epithelium (OEE). The secretory stage stratum intermedium was distinguished by p63-positive epithelial stem cell marks, highly specific alkaline phosphatase labeling, as well as multiple desmosomes and gap junctions. At the location of the presecretory stage stellate reticulum, the pre-eruption EO prominently featured the papillary layer (PL) as a keratin immunopositive network of epithelial strands between tooth crowns and oral epithelium. PL cell strands contained numerous p63-positive epithelial stem cells, while BrdU proliferative cells were detected at the outer boundaries of the PL, suggesting that the stellate reticulum/PL epithelial cell sheath proliferated to facilitate an epithelial seal during tooth eruption. Comparative histology studies demonstrated continuity between the OEE and the general lamina of continuous tooth replacement in reptiles, and the outer layer of Hertwig's epithelial root sheath in humans, implicating the OEE as the formative layer for continuous tooth replacement and tooth root extension. Cell fate studies in organ culture verified that the cervical portion of the mouse molar EO gave rise to Malassez rest-like cell islands. Together, these studies indicate that the nonameloblast layers of the EO play multiple roles during odontogenesis, including the maintenance of several p63-positive stem cell reservoirs, a role during tooth root morphogenesis and tooth succession, a stabilizing function for the ameloblast layer, the facilitation of ion transport from the EO capillaries to the enamel layer, as well as safe and seamless tooth eruption.

SCF promotes dental pulp progenitor migration, neovascularization, and collagen remodeling - potential applications as a homing factor in dental pulp regeneration.

Stem cell factor (SCF) is a powerful chemokine that binds to the c-Kit receptor CD117 and has shown promise as a homing agent capable of progenitor cell recruitment. In the present study we have documented high levels of both SCF and its receptor c-Kit in differentiating dental pulp (DP) cells and in the sub-odontoblastic layer of Höhl. In vitro studies using human DP progenitors revealed a significant increase in cell proliferation after100 nM SCF application, explained by a 2-fold upregulation in cyclin D3 and FGF2 cell cycle regulators, and a 7-fold increase in CDK4 expression. DP cell migration in the presence of SCF was up-regulated 2.7-fold after a 24 h culture period, and this effect was accompanied by cytoskeletal rearrangement, a 1.5-fold increase in polymeric F-actin over G-actin, and a 1.8-fold increase in RhoA expression. Explaining the signaling effect of SCF on DP migration, PI3K/Akt and MEK/ERK pathway inhibitors were demonstrated to significantly reduce DP cell migration, while SCF alone doubled the number of migrated cells. ERK and AKT phosphorylation were dramatically upregulated already 3-5 min after SCF addition to the culture medium and declined thereafter, classifying SCF as a fast acting chemokine. When applied as an agent to promote tissue regeneration in subcutaneously implanted collagen sponges, SCF resulted in a 7-fold increase in the cell number in the implanted tissue construct, a more than 9-fold increase in capillaries, as well as collagen sponge remodeling and collagen fiber neogenesis. Together, these studies demonstrate the suitability of SCF as a potent aid in the regeneration of dental pulp and other mesenchymal tissues, capable of inducing cell homing, angiogenesis, and tissue remodeling.

Three-dimensional finite element analysis of the craniomaxillary complex during maxillary protraction with bone anchorage vs conventional dental anchorage.

INTRODUCTION: The aim of this study was to explore the biomechanical effects on the craniomaxillary complex of bone anchorage and dental anchorage during maxillary protraction. METHODS: We established 2 finite element models. One simulated maxillary protraction with dental anchorage in the maxillary first molars and the other with bone anchorage in the infrazygomatic buttresses of the maxilla. The magnitude of the applied forces was 500 g per side, and the force directions were 0°, 10°, 20°, and 30° forward and downward relative to the occlusal plane. RESULTS: The finite element model of the craniomaxillary complex could displace in an almost translatory manner when the force direction was about 20° in the bone anchorage model and about 30° in the dental anchorage model. The nodes representing the sutures at the back of the maxilla showed greater stress in the bone anchorage model than in the dental anchorage model in the same force direction. It is the opposite at the front of the maxilla. CONCLUSIONS: We should determine the direction of applied force according to the anchorage location and skeletal characteristics of patients before maxillary protraction. The dramatic effects of maxillary protraction with bone anchorage can be based on the advantages of bone anchorage, not on the changes in the region of the applied force.

Ameloblastin modulates osteoclastogenesis through the integrin/ERK pathway.

Proteins of the extracellular matrix often have multiple functions to facilitate complex tasks ranging from signaling to structural support. Here we have focused on the function of one of the matrix proteins expressed in bones and teeth, the matrix adhesion protein ameloblastin (AMBN). Transgenic mice with 5-fold elevated AMBN levels in mandibles suffered from root cementum resorption, delamination, and reduced alveolar bone thickness. AMBN gain of function also resulted in a significant reduction in trabecular bone volume and bone mass dentistry in 42 days postnatal mouse jaws. In an in vitro model of osteoclastogenesis, AMBN modulated osteoclast differentiation from bone marrow derived monocytes (BMMCs), and dramatically increased osteoclast numbers and resorption pits. Furthermore, AMBN more than doubled BMMC adhesion, accelerated cell spreading, and promoted podosome belt and actin ring formation. These effects were associated with elevated ERK1/2 and AKT phosphorylation as well as higher expression of osteoclast activation related genes. Blocking integrin α2ß1 and ERK 1/2 pathways alleviated the effects of AMBN on osteoclast differentiation. Together, our data indicate that AMBN increases osteoclast number and differentiation as well as mineralized tissue resorption by regulating cell adhesion and actin cytoskeleton polymerization, initiating integrin-dependent extracellular matrix signaling cascades and enhancing osteoclastogenesis.

Changes of caspase-1 after the application of orthodontic forces in the periodontal tissues of rats.

OBJECTIVE: To investigate the changes of caspase-1 in orthodontic tooth movement and to determine whether the changes are phase-specific. MATERIALS AND METHODS: Eighty Wistar rats were included in this study. Sentalloy closed-coil springs were placed to induce a mesial traction force on the lower right first molar. The animals were killed after 1, 3, 7, and 14 days (n = 20 at each time point). The mandibles of 10 rats were sampled for histomorphometric analysis and immunohistochemical assay, and the periodontal tissues of 10 other rats were sampled for detecting caspase-1 mRNA and protein by real-time RT-PCR and by Western blotting, respectively. RESULTS: The inflammatory reaction was evident in paraffin sections with hematoxylin-eosin staining. The immunohistochemical assay showed that orthodontic forces significantly increased the number of caspase-1-positive cells in the periodontal ligament (PDL). Mechanical force triggered an increase of caspase-1 mRNA in periodontal tissues. The expression of caspase-1 mRNA increased from day 1, reached the peak on day 3, and then decreased. The results of Western blotting indicated that the levels of both procaspase-1 and P20 subunit significantly increased after the application of orthodontic forces, compared with those in controls (P < .05). CONCLUSION: Caspase-1 level increases during orthodontic tooth movement and changes with different phases, which might play a significant role in orthodontic tooth movement.

[Single cell gel electrophoresis of a magnesium alloy coated with beta-tricalcium phosphate].

OBJECTIVE: To evaluate the genotoxicity of a magnesium alloy coated with beta-tricalcium phosphate (beta-TCP). METHODS: Four groups were designed. In the first group, AZ31B magnesium alloy surface was coated with beta-TCP using chemical bath deposition, and in the second group magnesium alloy was tested. The other two groups were negative control (pure titanium) and positive control groups (0.5 mg/L bleomycin). Single cell gel electrophoresis was adopted to investigate genotoxicity of the alloy samples in different groups, and 60 cells from each group were analysed. Tail moment and tail DNA percentage were used as reliable indicators to show DNA damage in lymphocytes induced by every testing sample. Student-Newman-Keuls (SNK) test was used to compare results from 4 groups. RESULTS: There were no significant differences in tail moment and tail DNA percentage between magnesium alloy group [(0.52 +/- 0.12), (6.82 +/- 1.81)%] and magnesium alloy coated with beta-TCP group [(0.51 +/- 0.12), (6.89 +/- 1.93)%, P > 0.05]. Tail moment and tail DNA percentage in negative group were (0.47 +/- 0.14) and (6.29 +/- 1.64)%, and tail moment and tail DNA percentage in positive group were (5.17 +/- 1.23) and (22.09 +/- 4.51)%. CONCLUSIONS: No significant increase was found in DNA damage in lymphocytes induced by magnesium alloy coated with beta-TCP.