Concerns, Knowledge, and Practices of Dentists in Mexico Regarding Infection Control during the Coronavirus Disease Pandemic: A Cross-Sectional Study.

Dentists are highly exposed and vulnerable during the coronavirus disease (COVID-19) pandemic, as physical proximity to patients is necessary for effective dental examination and treatment. The objective of this study was to describe the concerns, knowledge, and infection control practices of dentists in Mexico during the COVID-19 pandemic. In this cross-sectional study conducted from 22 May 2020 to 8 July 2020, an anonymous survey was distributed to dentists, which covered information regarding dentists' sociodemographic and professional characteristics, clinical practices during the pandemic, and perceptions regarding the application of infection prevention and control guidance for dental settings during the COVID-19 pandemic. Out of 703 respondents, 73.1% (n = 514) were women and 53.6% (n = 377) were dentists with 1-10 years of experience. Regarding the statements issued by the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), the responses for 11 survey items had total agreement rates >90% (high frequency); seven and nine items had moderate and low frequency of total agreement, respectively. Most dentists in this study agreed with the WHO and CDC statements and were concerned regarding the possibility of infection, despite using the protective gear.

Sublingual dermoid cyst in an infant: A case report and review of the literature.

Dermoid cysts usually occur later in the second decade of life; we present the approach of an unusual case of an infant who presented a cyst within the oral cavity, which is important because it can be confused with other pathologies.

Efectos de la terapia periodontal no quirúrgica sobre el control glucémico de la Diabetes Mellitus Tipo 2: Revisión de literatura / Effects of non-surgical periodontal therapy on glycemic control of Type 2 Diabetes Mellitus: A literature review

Resumen Objetivo: Conocer la relación entre la enfermedad periodontal y la diabetes mellitus tipo 2, en el control de la glucemia. Diseño y métodos de investigación: Se realizó una búsqueda bibliográfica utilizando una base de datos (PubMed) con restricción del idioma inglés, buscando las investigaciones más recientes y con el mayor número de sujetos de investigación. Resultados: Los artículos revisados coinciden en que el tratamiento de la enfermedad periodontal mejora el control glucémico en pacientes con diabetes mellitus tipo 2, con una disminución promedio de 0,69% en el nivel de hemoglobina glucosilada (HbA1c). Conclusiones: El tratamiento periodontal mejora el control de la glucemia en pacientes con Diabetes Mellitus Tipo 2, debido a que disminuye el estado de inflamación sistémica y por lo tanto, también la cantidad de células inflamatorias (como IL6 y TNF- α) que provocan alteraciones en la actividad de la insulina.

Abstract Objective: To know the relationship between periodontal disease and type 2 diabetes mellitus in the control of blood glucose. Design and research methods: A bibliographic search was conducted using a database (PubMed) with english language restriction, looking for the most recent research and with the largest number of research subjects. Results: The articles reviewed coincide in the treatment of periodontal disease improves glycemic control in patients with diabetes mellitus type 2, with an average of 0.69% in the level of glycosylated hemoglobin (HbA1c). Conclusions: Periodontal treatment improves glycemic control in patients with Type 2 Diabetes Mellitus, as well as the number of inflammatory cells (such as IL6 and TNF-α) that cause alterations in insulin activity.

PD-1, TIM-3, and LAG-3 Expression in T Cells in a Patient with Recurrent Ossifying Fibroma: A Case Report.

Central ossifying fibroma is a benign, slow-growing tumor of mesenchymal origin with a predilection for the mandibular premolar and molar areas. The immunophenotype of T cells involved in the antitumor response against this benign tumor is unknown. In this case report, we described a case of a 48-year-old woman presenting with a very large recurrent ossifying fibroma in the mandible, which was successfully treated with hemimaxillectomy. In addition, we evaluated the expression of programmed cell death 1 receptor (PD-1), lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), CD69 (activation inducer molecule), and CD25 (α chain of the high-affinity IL-2 receptor) in T cell populations from the tumor and peripheral blood of this uncommon lesion. The patient presented recurrent ossifying fibroma, and the tumor-infiltrating and peripheral blood T cells showed expression of PD-1, LAG-3, and TIM-3, suggesting an exhausted T cell response.

Correlation between caries history and laser fluorescence of sound tooth enamel in restored and unrestored dentition.

The aim of this study was to determine the correlation between laser fluorescence (LF) values of apparently sound tooth enamel and caries history. LF measurements were recorded from six sound enamel tooth surfaces in each of 346 subjects aged 8-25 years. Caries experience was evaluated using the decayed, missing, and filled tooth (DMFT) index and the International Caries Detection and Assessment System (ICDAS). To measure differences between the unrestored and restored tooth groups, an unpaired two-sample t-test was used. To assess the relationship between LF of sound enamel and caries experience based on the DMFT and ICDAS, Pearson's correlation coefficient and linear regression analyses were used. The LF values of sound dental enamel in subjects with no history of invasive dental treatment were highly correlated with caries experience, as measured by the DMFT index (R = 0.76) and ICDAS (R = 0.7). The LF values of sound enamel in subjects with a history of previous invasive dental treatment were weakly correlated with caries experience, as measured by the DMFT index (R = 0.33), and moderately correlated with the ICDAS values (R = 0.66). The LF value of clinically healthy tooth enamel correlates with caries status based on the DMFT or ICDAS.

Análisis de la relación entre la hipomineralización incisivo molar y los factores asociados a su etiología / Analysis of the relationship between molar incisor hypomineralization and the factors associated with its etiology

RESUMEN El objetivo de este artículo es analizar la relación entre la hipomineralización incisivo molar (HIM) y los factores asociados a su etiología publicados en la literatura. Material y métodos: El estudio se basó en una búsqueda de estudios epidemiológicos de casos y controles de HIM que describieron un factor etiológico asociado para obtener las odds ratio (OR) necesarias para analizar la prevalencia del factor afectado y su posible papel en la etiología de la condición. Resultados: Ocho artículos cumplieron los criterios para el análisis. La población total analizada consistió en una muestra de 7,901 sujetos, de los cuales 992 tenían HIM. En estos sujetos fueron reportados como factor asociado (FA) para HIM: asma (OR = 4.4954), uso de antibióticos (OR = 5.5348), fiebre (OR = 4.0545) y neumonía. Conclusión: Los resultados del presente estudio sugieren que un FA común a todos los casos de HIM estudiados es un proceso inflamatorio que conduce a una mayor concentración de agentes en el microambiente en el que se desarrollan las células formadoras del esmalte, lo que aumenta la presencia de proteínas en la matriz del esmalte o interfieren con su hidrólisis y eliminación y produce como resultado una deficiente mineralización.

ABSTRACT Hypomineralization enamel of the first permanent molars is the most common developmental abnormalities observed in the teeth. The aetiology of MIH remains unclear and may have a multifactor aetiology. The aim of this paper is to analyze the relationship between MIH and associated factors published in the literature. Material and methods: The study was based on a search for epidemiological case-control studies of MIH that described an associated etiological factor, in order to obtain the odds ratios needed to analyze the prevalence of the factor concerned and its possible role in the etiology of the condition. Results: The initial search produced 50 articles, eight of which met the criteria for the analysis. The total population analyzed consisted of a sample of 7,901 subjects, 992 of whom had MIH (i.e., a prevalence of 12.55%). Asthma was reported as an etiological factor in five papers, which included 474 subjects with MIH with an OR of 4.4954 (p < 0.0001). Antibiotic use was reported as an etiological factor in three papers, which reported on a population of 231 subjects with MIH and OR of 5.5348 (p < 0.0001). Fever was reported as an etiological factor in two papers, involving a population of 176 subjects with MIH and an OR of 4.0545 (p < 0.0001). Pneumonia was reported as an etiological factor in two papers, which dealt with a population of 454 cases of MIH and produced an OR of 2.285 (p < 0.0001). Conclusion: The results of the present study suggest that one etiological factor common to all of the MIH cases studied is an infl ammatory process, in which the presence of agents that cause alterations in ameloblasts can lead to higher concentrations of these agents in the microenvironment in which enamel forming cells develop, thus increasing the presence of proteins in the enamel matrix or interfering with their hydrolysis and removal, producing defects in enamel mineralization.

Establishment and characterization of a cell population derived from a dentigerous cyst.

BACKGROUND: Dentigerous cyst (DC) occurs in approximately 20% of jaw cysts, being the second major common odontogenic cyst, after radicular cyst. This oral lesion has the ability to destroy maxillary bones and could be the origin of several odontogenic tumors. However, molecules implicated in its pathogenesis as well as those involved in its neoplastic transformation remain unknown. Here, we established a cell population derived from a DC as an in vitro model for the study of this oral lesion. METHODS: Cell culture was performed from a DC from a 44-year-old male. Cells were cultured at 37°C in DMEM/F12 medium containing 10% fetal bovine serum. Expression of epithelial markers was analyzed by Western blot and immunofluorescence. Ultrastructural characterization was carried out by transmission electron microscopy. Conditioned media were obtained and characterized by zymography and Western blot. RESULTS: Cells showed spindle-shaped morphology, but they express epithelial markers, such as cytokeratins and the odontogenic ameloblast-associated protein. The ultrastructural analysis showed well-formed desmosomes present in adhering contiguous cells, confirming the epithelial lineage of this cell population. Cells also contain several vesicles adjacent to plasma membrane, suggesting an active secretion. Indeed, the analysis of the conditioned medium revealed the presence of several secreted proteins, among them the matrix metalloproteinase-2. CONCLUSIONS: Our work provides a useful model to identify the molecular mechanisms involved in the pathogenesis of DC.

Orosomucoid-1 Expression in Ameloblastoma Variants.

Odontogenic tumors constitute a group of heterogeneous lesions of benign and malignant neoplasms with variable aggressiveness. Ameloblastomas are a group of benign but locally invasive neoplasms that occur in the jaws and are derived from epithelial elements of the tooth-forming apparatus. We previously described orosomucoid-1 protein expression in odontogenic myxomas. However, whether orosomucoid-1 is expressed in other odontogenic tumors remains unknown. Since orosomucoid-1 belongs to a group of acute-phase proteins and has many functions in health and disease, we identified and analyzed orosomucoid-1 expression in ameloblastoma variants and ameloblastic carcinoma using western blot and immunohistochemical techniques. Thirty cases of ameloblastoma were analyzed for orsomucoid-1; five specimens were fresh for western blot study (four benign ameloblastomas and one ameloblastic carcinoma), and 25 cases of benign ameloblastoma for immunohistochemical assays. Orosomucoid-1 was widely expressed in each tumor variant analyzed in this study, and differential orosomucoid-1 expression was observed between benign and malignant tumor. Orosomucoid-1 may play an important role in the behavior of ameloblastomas and influence the biology and development of the variants of this tumor.

Expression of the transcription factor PITX2 in ameloblastic carcinoma.

Ameloblastic carcinoma is a rare odontogenic tumour that combines the histological features of ameloblastoma with cytological atypia. Until 2005, the incidence of ameloblastic carcinoma was unknown, and since then, fewer than 60 cases have been reported. These tumours may originate from pre-existing tumours or cysts, or they arise de novo from the activation or transformation of embryological cells. PITX2 is a transcription factor that is a product and regulator of the WNT cell signalling pathway, which has been involved in development of several tumours. To analyse whether PITX2 could be involved in the biological behaviour of ameloblastic carcinoma, we analysed the expression of this transcription factor in a sample of this tumour and nine benign ameloblastomas to compare. The results of Western blotting and RT-PCR analyses were positive, and considering the hundreds of genes that PITX2 regulates, we believe that its expression could be intimately linked to the behaviour of ameloblastic carcinoma and possibly other odontogenic lesions.

Identification of proteins with increased levels in ameloblastic carcinoma.

PURPOSE: The comparative proteomic approach by a combination of 2-dimensional electrophoresis and matrix-assisted laser desorption-ionization-time of flight mass spectrometry (MS) analysis is an attractive strategy for the discovery of cancer biomarkers and therapeutic targets. The identification of protein biomarkers associated with ameloblastic carcinoma (AC), a malignant epithelial odontogenic tumor, will potentially improve the diagnostic and prognostic accuracy for this malignant neoplasm. The aim of the present study was to identify highly expressed proteins in AC that could be considered as potential biomarkers. MATERIALS AND METHODS: The protein profile of an AC was compared with the protein profiles of 3 cases of benign ameloblastoma. Proteins that showed increased levels in AC were identified using MS, and the augmented amount of some of these proteins in the malignant lesion was confirmed by Western blot or immunohistochemistry. RESULTS: We detected a total of 782 spots in the protein profile of AC, and 19 of them, showing elevated levels compared with benign ameloblastoma, were identified using MS. These proteins have been implicated in several cellular functions, such as cell structure, metabolism, stress response, and signal transduction. CONCLUSIONS: The increased expression of the identified proteins and the minor expression of some proteins that might inhibit tumor progression could be involved in the evolution from a benign lesion to carcinoma.

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma.

BACKGROUND: Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control. RESULTS: We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm. CONCLUSION: Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM.

Identification of a polypeptide containing Tudor and staphyloccocal nuclease-like domains as the sequence-specific binding protein to the upstream regulatory element 1 of Entamoeba histolytica.

Transcription initiation is the most regulated stage for the control of gene expression. This event requires that a complex of proteins called transcription factors bind to DNA through cis-regulatory elements located in the gene promoters. However, little is known about transcription regulation in Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis. Some genes encoding for proteins involved in the parasite pathogenicity contain specific upstream regulatory elements (URE1-URE5) in their promoters. Here, we identified the protein that specifically binds to the URE1 sequence (EhURE1BP). This protein contains five SNase domains and one Tudor motif, and has 21% identity and 36% similarity to the multifunctional eukaryotic protein known as the protein containing Tudor and staphyloccocal nuclease-like domains (TSN). To obtain antibodies against EhURE1BP, the recombinant protein was expressed and immunised in rabbits. Western blot and immunofluorescence assays showed that EhURE1BP is located in both nuclei and cytoplasm. Electrophoretic mobility shift assays and supershift assays demonstrated that EhURE1PB specifically binds to URE1 and that the C-terminus that includes the Tudor motif contains the DNA-binding domain of this protein. Results suggest that this TSN-like protein is the transcription factor that activates the transcription of some pathogenicity-related genes of E. histolytica.