Evaluation of Mental Foramen and Mandibular Canal Course and Location in an Emirati Subpopulation.

INTRODUCTION AND AIMS: Violations of the mandibular canal (MC) and mental foramen (MF) and subsequent injuries to their neurovascular bundle have been reported after surgical and nonsurgical dental procedures. Besides using advanced technologies such as cone-beam computed tomography (CBCT), clinicians should be aware of the anatomy and location of MC and MF in different populations. This study aims to describe the morphologic characteristics of the MF, MC, and its intrabony location in relation to the apices of mandibular posterior teeth in an Emirati subpopulation using CBCT. METHODS: A total of 3700 CBCT scans were screened, and 154 scans that met the inclusion and exclusion criteria were randomly selected. The scans were assessed using 3-dimensional multiplanar imaging for the following structures: the location of MF and the MC course, its intrabony location, and its relationship to the apices of the mandibular posterior teeth. The data were analysed statistically using SPSS software. RESULTS: The MC ran lingually and inferiorly at the posterior region and became more buccal and superior towards the MF. The distal root of the mandibular second molar was found to be the closest root to the MC (2.06 ± 1.83 mm). Moreover, the most common location of the MF was distal to the contact area between the 2 premolars (0.83 ± 1.84 mm) with a significant negative correlation to age (with and increase in age, the MF moves distally). The distance between the root apices and the MC was statistically significantly affected by age (positive correlation) and gender (male patients had a greater distance). CONCLUSIONS: The common course of the MC is lingual and inferior posteriorly and becomes more buccal and superior towards the MF, which is located mostly between the mandibular first and second premolars. Furthermore, the distal root of the mandibular second molar is the closest to the MC and has a positive relationship with age.

The Molecular Landscape of Lung Metastasis in Primary Head and Neck Squamous Cell Carcinomas.

Background Lung metastasis in head and neck cancer (HNC) patients is a critical concern, often indicating an advanced disease stage and a poor prognosis. This study explores the molecular complexities of such metastases, identifying specific genes and pathways that may serve as valuable targets for diagnosis and treatment. The findings underscore the potential for significantly improved patient outcomes through targeted therapeutic strategies. Methodology In this research, we systematically collected raw gene expression data from head and neck squamous cell carcinoma (HNSCC) and lung squamous cell carcinoma (LSCC). By comparing tumorous and normal gene expression profiles from paired patient samples, we identified differentially expressed genes (DEGs). Network analysis helped visualize protein interactions and pinpoint crucial hub genes. Through validation and comparison across several datasets, we identified common DEGs. Additionally, we employed Kaplan-Meier analysis and log-rank testing to examine the relationship between gene expression patterns and patient survival. Result The study identified 145 overlapping DEGs in both HNSCC and LSCC, which are crucial for cancer progression and linked to lung metastasis, offering vital targets for personalized therapy by identifying key genes affecting disease development and patient survival. Pathway analyses linked these to lung metastasis, while protein-protein interaction network construction and hub gene identification highlighted genes crucial for development and patient survival, offering targets for personalized therapy. Conclusion Identifying key genes and pathways in lung metastasis from HNC, this study highlights potential targets for enhanced diagnosis and therapy. It underscores the crucial role of molecular insights in driving forward personalized treatment approaches and improving patient outcomes.

Awareness of Periodontal Health among Pregnant Females in Government Setting in United Arab Emirates.

OBJECTIVE: Periodontal disease is one of the most common infectious diseases. Several factors are associated with increased susceptibility of periodontal disease such as hormonal changes during pregnancy. Although pregnancy does not directly cause gingivitis, it can aggravate preexisting periodontal disease. This study aimed to evaluate knowledge of the association between periodontal disease and pregnancy in pregnant females. MATERIALS AND METHODS: A convenience sample of pregnant females attending two United Arab Emirates government hospitals was recruited for this study. A 23-item questionnaire was developed with four sections, covering sociodemographic details, oral hygiene, oral symptoms during pregnancy, and knowledge of periodontal health during pregnancy. The study was conducted between April and October 2017. All participants consented to the survey. RESULTS: A total of 100 participants with a mean age of 31 years (± 5.9) completed the survey. Most respondents brushed their teeth 2 to 3 times a day (65%), used a manual toothbrush (93%) but only visited the dentist when in pain (62%). Few respondents self-reported any gingival signs and symptoms during pregnancy; 38% had bleeding gums, 27% had no gum swelling, and 34% had bad odor/taste/smell. Only 21% of pregnant females lost a tooth/teeth during pregnancy, 15% believed that pregnancy increased the likelihood of gum disease, and 66% of gynecologists did not advise a visit to the dentist.Housewives were significantly less knowledgeable about periodontal health than students/employed respondents (p = 0.01). Quality of knowledge was not associated with educational attainment (< 0.06). Respondents > 30 years of age were more likely to believe in "a tooth for a baby" than younger participants aged < 30 years (p < 0.05). A logistic regression model showed that educational attainment was not a predictor for the belief in "a tooth for a baby" but age was a significant predictor (odds ratio = 2.0). CONCLUSION: Protocols should be developed in antenatal clinics in order to improve periodontal health in pregnant females and to prevent complications that can result in adverse pregnancy outcomes.

Health research prioritization in Somalia: setting the agenda for context specific knowledge to advance universal health coverage.

Introduction: Despite recognition that health research is an imperative to progress toward universal health coverage, resources for health research are limited. Yet, especially in sub-Saharan Africa, more than 85% of the resources available for health research are spent on answering less relevant research questions. This misalignment is partially due to absence of locally determined health research priorities. In this study, we identified health research priorities which, if implemented, can inform local interventions required to accelerate progress toward universal health coverage in Somalia. Methods: We adapted the child health and nutrition research initiative method for research priority setting and applied it in 4 major phases: (1) establishment of an exercise management team, (2) a web-based survey among 84 respondents to identify health research questions; (3) categorization of identified health research questions; and (4) a workshop with 42 participants to score and rank the identified health research questions. Ethical approval was received from ethics review committee of the London School of Hygiene and Tropical Medicine (Ref:26524) and the Somali Research and Development Institute (Ref: EA0143). Results: Two hundred and thirty-one unique health research questions were identified and categorized under health systems, services and social determinants (77), communicable diseases (54), non-communicable diseases (41) and reproductive, maternal, new-born, child, adolescent health and nutrition (59). A priority score ranging from 1 to 9 was assigned to each of the questions. For each category, a list of 10 questions with the highest priority scores was developed. Across the four categories, an overall list of 10 questions with the highest priority scores was also developed. These related to bottlenecks to accessing essential health services, use of evidence in decision making, antimicrobial resistance, distribution and risk factors for non-communicable diseases, post-traumatic stress disorder and factors associated with low antenatal care attendance among others. Conclusion and recommendations: The developed priority research questions can be used to focus health research and to inform appropriation of health research resources to questions that contribute to generation of local health system knowledge which is required to accelerate progress toward universal health coverage in Somalia. The Somalia national institute of health should set up a consortium for provision of technical and financial support for research addressing the identified priority research questions, establish a mechanism to continuously monitor the extent to which new health interventions in Somalia are informed by knowledge generated through conducting prioritized health research and prioritize interventions aimed at strengthening the broader national health research system for Somalia.

The changing characteristics of a cohort of children and adolescents living with HIV at antiretroviral therapy initiation in Asia.

Despite improvements in HIV testing and earlier antiretroviral therapy (ART) initiation in children living with HIV through the years, a considerable proportion start treatment with advanced disease. We studied characteristics of children and adolescents living with HIV and their level of immunodeficiency at ART initiation using data from a multi-country Asian cohort. We included children and adolescents who were ART-naïve and <18 years of age at ART initiation from 2011 to 2020 at 17 HIV clinics in six countries. Incidence rates of opportunistic infections (OIs) in the first two years of triple-drug ART (≥3 antiretrovirals) was also reported. Competing risk regression analysis was performed to identify factors associated with first occurrence of OI. In 2,027 children and adolescents (54% males), median age at ART initiation increased from 4.5 years in 2011-2013 to 6.7 in 2017-2020, median CD4 count doubled from 237 cells/µl to 466 cells/µl, and proportion of children who initiated ART as severely immunodeficient decreased from 70% to 45%. During follow-up, 275 (14%) children who received triple-drug ART as first treatment and had at least one clinic visit, developed at least one OI in the first two years of treatment (9.40 per 100 person-years). The incidence rate of any first OI declined from 12.52 to 7.58 per 100 person-years during 2011-2013 and 2017-2020. Lower hazard of OIs were found in those with age at first ART 2-14 years, current CD4 ≥200 cells/µl, and receiving ART between 2017 and 2020. The analysis demonstrated increasing number of children and adolescents starting ART with high CD4 count at ART start. The rate of first OI markedly decreased in children who started ART in more recent years. There remains a clear need for improvement in HIV control strategies in children, by promoting earlier diagnosis and timely treatment.

Molecular insights into the role of electronic cigarettes in oral carcinogenesis.

Electronic cigarette (EC) usage or vaping has seen a significant rise in recent years across various parts of the world. They have been publicized as a safe alternative to smoking; however, this is not supported strongly by robust research evidence. Toxicological analysis of EC liquid and aerosol has revealed presence of several toxicants with known carcinogenicity. Oral cavity is the primary site of exposure of both cigarette smoke and EC aerosol. Role of EC in oral cancer is not as well-researched as that of traditional smoking. However, several recent studies have shown that it can lead to a wide range of potentially carcinogenic molecular events in oral cells. This review delineates the oral carcinogenesis potential of ECs at the molecular level, providing a summary of the effects of EC usage on cancer therapy resistance, cancer stem cells (CSCs), immune evasion, and microbiome dysbiosis, all of which may lead to increased tumor malignancy and poorer patient prognosis. This review of literature indicates that ECs may not be as safe as they are perceived to be, however further research is needed to definitively determine their oncogenic potential.

Effect from Autoclave Sterilization and Usage on the Fracture Resistance of Heat-Treated Nickel-Titanium Rotary Files.

This study aimed to assess the effect of mechanical loading and heating on the cyclic fatigue and torsional fracture resistances of heat-treated nickel-titanium files after usage and autoclaving. Sixty files (One Curve) were tested for cyclic fatigue and torsional fracture resistances using customized devices. The files were divided into three groups according to the test conditions (n = 10); new (group-N), used for simulated canal shaping (group-U), and sterilized after use (group-S). For cyclic fatigue resistances, the files were freely rotated in a curved metal canal under body temperature; the time elapsed to fracture was recorded and the numbers of cycles to fracture (NCF) were calculated. For the torsional resistances, the file tip was fixed and rotated until the file fractured. The maximum torsional load and distortion angle were recorded. The toughness was calculated. Fracture fragments were examined with a scanning electron microscope. Data were analyzed using a one-way analysis of variance and Tukey's post hoc test at the significance level of 95%. Group-U showed significantly higher NCF than group-S (p < 0.05). However, there was no significant differences between groups-N and -S in the NCF (p > 0.05). Group-N showed a significantly bigger distortional angle and higher torsional toughness than groups-U and -S, but the ultimate torsional strength did not have significant difference between the groups. Under the limitation of this study, autoclave sterilization after single-usage did not improve the fracture resistance of heat-treated One Curve nickel-titanium files.

Bacteroides ovatus alleviates dysbiotic microbiota-induced intestinal graft-versus-host disease.

Acute gastrointestinal intestinal GVHD (aGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation, and the intestinal microbiota is known to impact on its severity. However, an association between treatment response of aGI-GVHD and the intestinal microbiota has not been well-studied. In a cohort of patients with aGI-GVHD (n=37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and loss of Bacteroides ovatus from the microbiome. In a mouse model of carbapenem-aggravated GVHD, introducing Bacteroides ovatus reduced severity of GVHD and improved survival. Bacteroides ovatus reduced degradation of colonic mucus by another intestinal commensal, Bacteroides thetaiotaomicron, via its ability to metabolize dietary polysaccharides into monosaccharides, which then inhibit mucus degradation by Bacteroides thetaiotaomicron and reduce GVHD-related mortality.

Disclosure of HIV status and associated clinical outcomes of children and adolescents living with HIV in Asia.

Disclosure of HIV status is an important part of pediatric care. We studied disclosure and clinical outcomes in a multi-country Asian cohort of children and adolescents with HIV. Those 6-19 years of age who initiated combination antiretroviral therapy (cART) between 2008 and 2018, and who had at least one follow-up clinic visit were included. Data up to December 2019 were analyzed. Cox and competing risk regression analyses were used to assess the effect of disclosure on disease progression (WHO clinical stage 3 or 4), loss to follow-up (LTFU; > 12 months), and death. Of 1913 children and adolescents (48% female; median [IQR] age 11.5 [9.2-14.7] years at last clinic visit), 795 (42%) were disclosed to about their HIV status at a median age of 12.9 years (IQR: 11.8-14.1). During follow-up, 207 (11%) experienced disease progression, 75 (3.9%) were LTFU, and 59 (3.1%) died. There were lower hazards of disease progression (adjusted hazard ratio [aHR] 0.43 [0.28-0.66]) and death (aHR 0.36 [0.17-0.79]) for those disclosed to compared with those who were not. Disclosure and its appropriate implementation should be promoted in pediatric HIV clinics in resource-limited settings.

Mucus-degrading Bacteroides link carbapenems to aggravated graft-versus-host disease.

The intestinal microbiota is an important modulator of graft-versus-host disease (GVHD), which often complicates allogeneic hematopoietic stem cell transplantation (allo-HSCT). Broad-spectrum antibiotics such as carbapenems increase the risk for intestinal GVHD, but mechanisms are not well understood. In this study, we found that treatment with meropenem, a commonly used carbapenem, aggravates colonic GVHD in mice via the expansion of Bacteroides thetaiotaomicron (BT). BT has a broad ability to degrade dietary polysaccharides and host mucin glycans. BT in meropenem-treated allogeneic mice demonstrated upregulated expression of enzymes involved in the degradation of mucin glycans. These mice also had thinning of the colonic mucus layer and decreased levels of xylose in colonic luminal contents. Interestingly, oral xylose supplementation significantly prevented thinning of the colonic mucus layer in meropenem-treated mice. Specific nutritional supplementation strategies, including xylose supplementation, may combat antibiotic-mediated microbiome injury to reduce the risk for intestinal GVHD in allo-HSCT patients.

Fracture Resistance of Heat-Treated Nickel-Titanium Rotary Files After Usage and Autoclave Sterilization: An In Vitro Study.

INTRODUCTION: This study aimed to evaluate the dynamic cyclic fatigue resistance of heat-treated nickel-titanium (NiTi) files after usage and autoclaving. METHODS: Two heat-treated NiTi file systems with tip sizes of #25 (ie, ProTaper Gold F2 [Dentsply Sirona, Charlotte, NC] and TruNatomy Prime [Dentsply Sirona]) were selected. Files of each system were divided into 3 experimental subgroups (n = 10). For subgroup 1, new files were tested to establish the baseline number of cycles to failure (NCF). For subgroup 2, files underwent canal instrumentation in a simulated J-shaped canal block with 35° of curvature and a 16.5-mm length. The simulated canals were pre-enlarged using stainless steel files #10K and #15K. After instrumentation, the files were tested. For subgroup 3, files underwent canal instrumentation as in subgroup 2 followed by autoclave sterilization and then were tested for cyclic failure. The cyclic fatigue test was performed in dynamic pecking motion under body temperature. The time to fracture was recorded and calculated into NCF. Fracture fragment lengths were measured using a digital microcaliper. Statistical analysis was conducted using the independent t test and multifactorial analysis of variance with 95% significance. Scanning electron microscopy was used to examine the topographic characteristics after cyclic fatigue tests. RESULTS: There were no significant differences between file systems in subgroup 1 using new files (P < .05). Although PG reduced the NCF after use, TN showed a significantly increased NCF (P < .05). However, after sterilization, TN showed a reduced NCF compared with the used one (P < .05). CONCLUSIONS: Cyclic loading by usage and heat treatment during sterilization may result in different cyclic fatigue resistance according to the geometry and alloy characteristics.

Specific mesoderm subset derived from human pluripotent stem cells ameliorates microvascular pathology in type 2 diabetic mice.

Human induced pluripotent stem cells (hiPSCs) were differentiated into a specific mesoderm subset characterized by KDR+CD56+APLNR+ (KNA+) expression. KNA+ cells had high clonal proliferative potential and specification into endothelial colony-forming cell (ECFCs) phenotype. KNA+ cells differentiated into perfused blood vessels when implanted subcutaneously into the flank of nonobese diabetic/severe combined immunodeficient mice and when injected into the vitreous of type 2 diabetic mice (db/db mice). Transcriptomic analysis showed that differentiation of hiPSCs derived from diabetics into KNA+ cells was sufficient to change baseline differences in gene expression caused by the diabetic status and reprogram diabetic cells to a pattern similar to KNA+ cells derived from nondiabetic hiPSCs. Proteomic array studies performed on retinas of db/db mice injected with either control or diabetic donor-derived KNA+ cells showed correction of aberrant signaling in db/db retinas toward normal healthy retina. These data provide "proof of principle" that KNA+ cells restore perfusion and correct vascular dysfunction in db/db mice.

Severe Recurrent Bacterial Pneumonia Among Children Living With HIV.

BACKGROUND: Bacterial pneumonia imparts a major morbidity and mortality burden on children living with HIV, yet effective prevention and treatment options are underutilized. We explored clinical factors associated with severe recurrent bacterial pneumonia among children living with HIV. METHODS: Children enrolled in the TREAT Asia Pediatric HIV Observational Database were included if they started antiretroviral therapy (ART) on or after January 1st, 2008. Factors associated with severe recurrent bacterial pneumonia were assessed using competing-risk regression. RESULTS: A total of 3,944 children were included in the analysis; 136 cases of severe recurrent bacterial pneumonia were reported at a rate of 6.5 [95% confidence interval (CI): 5.5-7.7] events per 1,000 patient-years. Clinical factors associated with severe recurrent bacterial pneumonia were younger age [adjusted subdistribution hazard ratio (aHR): 4.4 for <5 years versus ≥10 years, 95% CI: 2.2-8.4, P < 0.001], lower weight-for-age z-score (aHR: 1.5 for <-3.0 versus >-2.0, 95% CI: 1.1-2.3, P = 0.024), pre-ART diagnosis of severe recurrent bacterial pneumonia (aHR: 4.0 versus no pre-ART diagnosis, 95% CI: 2.7-5.8, P < 0.001), past diagnosis of symptomatic lymphoid interstitial pneumonitis or chronic HIV-associated lung disease, including bronchiectasis (aHR: 4.8 versus no past diagnosis, 95% CI: 2.8-8.4, P < 0.001), low CD4% (aHR: 3.5 for <10% versus ≥25%, 95% CI: 1.9-6.4, P < 0.001) and detectable HIV viral load (aHR: 2.6 versus undetectable, 95% CI: 1.2-5.9, P = 0.018). CONCLUSIONS: Children <10-years-old and those with low weight-for-age, a history of respiratory illness, low CD4% or poorly controlled HIV are likely to gain the greatest benefit from targeted prevention and treatment programs to reduce the burden of bacterial pneumonia in children living with HIV.

The C-shaped root canal systems in mandibular second molars in an Emirati population.

Our study aimed to describe the root and canal morphology of mandibular second molars in Emirati population and to study the prevalence and types of morphological change in C-shaped canal configuration along the root length in an effort to describe C-shaped molars as a unit. Cone beam computed tomography (CBCT) scans of Emirati patients were analyzed in multiple plans and root and canal configuration of mandibular second molars were evaluated. Moreover, specific types of morphological change in C-shaped canal configuration along root length were studied and reconstructed using 3D reconstruction software. A total of 508 mandibular second molars were evaluated. Among the non-C-shaped mandibular second molars, two separate roots were the most prevalent root morphology (78.3%). The mesial root's most common root canal configuration was Vertucci Type II (46.5%), and in the distal root, Vertucci Type I (90.5%). The prevalence of C-shaped mandibular second molars was 17.9% and was significantly prevalent (P < 0.001) in females. Specific types of morphological change in C-shaped molars along the root length were observed and described for the first time, in which the most common types of morphological change were C1-C2-C3d (18%), C1-C3c-C3d (15.4%), C4-C3c-C3d (7.7%), and C3c-C3c-C3d (7.7%). This study showed wide variations in the root and canal morphology in mandibular second molars in Emirati population with a relatively high prevalence of C-shaped canal configuration (17.9%). Moreover, specific types of morphological change in C-shaped configuration were detected and described for the first time in this population.

Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response.

Gut bacteria modulate the response to immune checkpoint blockade (ICB) treatment in cancer, but the effect of diet and supplements on this interaction is not well studied. We assessed fecal microbiota profiles, dietary habits, and commercially available probiotic supplement use in melanoma patients and performed parallel preclinical studies. Higher dietary fiber was associated with significantly improved progression-free survival in 128 patients on ICB, with the most pronounced benefit observed in patients with sufficient dietary fiber intake and no probiotic use. Findings were recapitulated in preclinical models, which demonstrated impaired treatment response to anti­programmed cell death 1 (anti­PD-1)­based therapy in mice receiving a low-fiber diet or probiotics, with a lower frequency of interferon-γ­positive cytotoxic T cells in the tumor microenvironment. Together, these data have clinical implications for patients receiving ICB for cancer.

The Use of Stem Cell-Derived Organoids in Disease Modeling: An Update.

Organoids represent one of the most important advancements in the field of stem cells during the past decade. They are three-dimensional in vitro culturing models that originate from self-organizing stem cells and can mimic the in vivo structural and functional specificities of body organs. Organoids have been established from multiple adult tissues as well as pluripotent stem cells and have recently become a powerful tool for studying development and diseases in vitro, drug screening, and host-microbe interaction. The use of stem cells-that have self-renewal capacity to proliferate and differentiate into specialized cell types-for organoids culturing represents a major advancement in biomedical research. Indeed, this new technology has a great potential to be used in a multitude of fields, including cancer research, hereditary and infectious diseases. Nevertheless, organoid culturing is still rife with many challenges, not limited to being costly and time consuming, having variable rates of efficiency in generation and maintenance, genetic stability, and clinical applications. In this review, we aim to provide a synopsis of pluripotent stem cell-derived organoids and their use for disease modeling and other clinical applications.

Complete Obturation-Cold Lateral Condensation vs. Thermoplastic Techniques: A Systematic Review of Micro-CT Studies.

To prevent re-infection and provide a hermetic seal of the root canal system, an endodontist must aim to produce a void-free obturation. This review aimed to compare the completeness of root canal obturation between the two most prevalent methods-cold lateral condensation and warm gutta-percha techniques-using micro-CT (PROSPERO reg no. 249815). MATERIALS AND METHODS: A search of Scopus, Embase, PubMed (Medline via PubMed), and Web of Science databases was done without any time restriction according to the PRISMA protocol. Articles that compared both techniques and were published in English were included. Data was extracted and the risk of bias was assessed using an adapted tool based on previous studies. RESULTS: A total of 141 studies were identified by the search. Following the screening and selection of articles, 9 studies were included for review. Data was extracted manually and tabulated. Most studies had a moderate risk of bias. None determined operator skill in both methods before comparison. The data extracted from the included studies suggests that both techniques produce voids in the obturation. The thermoplasticized gutta-percha techniques may result in fewer voids compared to cold lateral condensation. CONCLUSION: Considering the limitations of the included studies, it was concluded that neither technique could completely obturate the root canal. Thermoplasticized gutta-percha techniques showed better outcomes despite a possible learning bias in favor of cold lateral condensation. Establishing operator skills before comparison may help reduce this bias.

Taurine Augments Telomerase Activity and Promotes Chondrogenesis in Dental Pulp Stem Cells.

BACKGROUND: Stem cell therapy has become an advanced and state-of-the-art procedure to regenerate lost tissues of the human body. Cartilage repair is a challenging task in which stem cells find potential application. One of the important biologic modifiers that can cause chondrogenic differentiation of stem cells is taurine. However, taurine has not been investigated for its effects on dental pulp derived stem cell (DPSC) chondrogenic differentiation. OBJECTIVE: The objective of the study was to investigate if taurine administration to DPSCs heralds chondrogenic differentiation as ascertained by expression of SOX9, COL2A1, ACAN, ELN, and COMP. The study also investigated if the differentiated cells synthesized glycosaminoglycans, a marker of cartilage formation. The study also aimed to assess proliferative activity of the cells after taurine administration by measuring the hTERT gene and protein expression. MATERIALS AND METHODS: DPSCs were obtained from a molecular biology laboratory and characterization of stem cell markers was done by flow cytometry. The cells were subjected to a MTT assay using various concentrations of taurine. Following this, hTERT gene and protein estimation was done in the control, telomerase inhibitor treated DPSC (TI-III), 10 µM taurine treated DPSC, and TI-III + 10 µM taurine treated DPSCs. A polymerase chain reaction was done to assess gene expression of SOX9, COL2A1, ACAN, ELN, and COMP genes and glycosaminoglycans were estimated in control cells, Induced DPSCs, induced and TI-III treated DPSCs, and 10 µM taurine treated DPSCs. RESULTS: DPSCs expressed CD73, CD90, and CD105 and did not express CD34, CD45, and HLA-DR, which demonstrated that they were mesenchymal stem cells. The MTT assay revealed that various concentrations of taurine did not affect the cell viability of DPSCs. A concentration of 10 µM of taurine was used for further assays. With regard to the hTERT gene and protein expression, the taurine treated cells expressed the highest levels that were statistically significant compared to the other groups. Taurine was also found to restore hTERT expression in telomerase inhibitor treated cells. With regard to chondrogenesis related genes, taurine administration significantly increased the expression of SOX9, COL2A1, ACAN, and ELN genes in DPSCs and caused a significant increase in glycosaminoglycan production by the cells. CONCLUSIONS: Taurine can be regarded a biologic modifier that can significantly augment chondrogenic differentiation of DPSCs and can find potential applications in regenerative medicine in the area of cartilage regeneration.

Overview of transnational recommendations for COVID-19 transmission control in dental care settings.

On 11 March 2020, the World Health Organization (WHO) declared the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) as a pandemic. Until an effective treatment or a vaccine is developed, the current recommendations are to contain the disease, and control its transmission. It is now clear that the primary mode of SARS-CoV-2 transmission is aerosol/droplet spread, and by contacting virus-contaminated surfaces acting as fomites (inanimate vectors). Furthermore, recent data indicate that the live virus particles are present in saliva, and, more alarmingly, asymptomatic individuals may transmit the infection. By virtue of the nature of the practice of dentistry where intrinsically, a high volume of aerosols is produced, as well as the close proximity of dentists and patients during treatment, dentists and allied health staff are considered the highest risk health professional group for acquiring SARS-CoV-2 during patient management. Therefore, several organizations and specialty associations have proposed guidelines and recommendations for limiting the transmission of SARS-COV-2 from carriers to dentists and vice versa. This paper aims to provide a review of these guidelines, and concludes with a brief look at how the practice of dentistry may be impacted by COVID-19, in the post-pandemic era.

Evaluation of root and canal morphology of maxillary permanent first molars in an Emirati population; a cone-beam computed tomography study.

BACKGROUND: The aim of this study was to analyze the root and canal morphology of the maxillary permanent first molars in an Emirati population using cone-beam computed tomography (CBCT). METHODS: Two hundred and sixty-one CBCT scans were acquired. The data were extracted and anonymized to remove all patient identifiers. Two observers (an endodontic resident and an endodontist) evaluated all scans on diagnostic quality monitors. RESULTS: The prevalence of a second mesiobuccal canal (MB2) was 80.1% in all examined samples. Type II Vertucci classification, was the most common canal configuration (59%) in the mesiobuccal root, followed by Types I (19.9%) and IV (15.3%), while Type III was the least common (5.7%). Types I, II, and IV were significantly more common in the 21-40-year age group (P < 0.001), while Type III was observed significantly more often in the < 20-year age group (P < 0.001). No significant effect of gender on the prevalence of Vertucci classification in the mesiobuccal root of maxillary first molars (P = 0.74) was found. Analysis of bilateral symmetry showed that 80% teeth had perfect bilateral symmetry, whereas 20% were asymmetrical. Type II canal configuration showed the highest prevalence of bilateral symmetry (48.7%), followed by Type I (15%) and Type IV (10%), while Type III showed the least prevalence of symmetry (3%). CONCLUSIONS: This was the first study to analyze the prevalence of MB2 canal in an Emirati population. Our results indicate high prevalence of MB2 (80.1%) and emphasize the importance of using advanced techniques to locate the MB2 canal.