Role of Apoptotic Biomarkers in Ameloblastoma and Dental Follicle

Objectives Ameloblastoma is an odontogenic neoplasm with locally aggressive behavior. Fas and FasL play important roles in apoptotic pathways. The aim of this study was to determine the possible role of expression of apoptotic pathways (Fas and FasL) in human ameloblastoma and the relationship of apoptosis with the clinical biological characteristics of ameloblastoma. Methods In this descriptive retrospective study, we investigated the anti-Fas and anti-FasL antibody expression in 11 dental follicles and 56 ameloblastoma specimens (35 conventional, 15 unicystic and 6 ameloblastic carcinoma samples) by immunohistochemical (IHC) staining and polymerase chain reaction (PCR). The percentage of positive cells was calculated by using the Mann-Whitney U test and Kruskal-Wallis test. Results The rate of expression of markers was significantly lower in dental follicles than all subtypes of ameloblastoma (P=0.01 for Fas, and P=0.0001 for FasL). The FasL proportional score was significantly higher in conventional ameloblastoma than in unicystic ameloblastoma and ameloblastic carcinoma (P=0.003). There was no significant relationship between the type of ameloblastoma and expression of Fas. Conclusion This study shows that the process of apoptosis in ameloblastomais a sign of behavioral change in odontogenic epithelial cells especially in conventional ameloblastoma and that the apoptotic factors may not play an effective role in the malignancy of ameloblastoma

Cementoblastoma of the Mandible: A Case Report and Review of Literature

Objectives Cementoblastoma is a rare benign odontogenic tumor which is linked to the root of a vital tooth. This tumor is usually accompanied by pain and swelling, and its most common site is the left mandibular first molar. General dentists’ inattention to oral lesions, especially tooth-related radiopacities, is problematic in some cases and results in delayed or missed diagnosis.Case Our patient was a 31-year-old woman who presented to our clinic complaining of dull pain in the left mandibular first molar. Root canal therapy was performed for the patient but the pain continued for the next 2 years. The patient was referred to a surgeon. Panoramic radiography revealed a radiopaque mass of approximately 2 x 1 cm in diameter attached to the root of the mandibular left first molar. The lesion together with the involved tooth was removed by excisional biopsy. Histopathological diagnosis was cementoblastoma.Conclusion Dentists’ knowledge of pulpal, periapical and periodontal lesions is usually satisfactory, but their inattention to oral lesions, especially tooth-related radiopaque lesions, is problematic in some cases. Pain from cementoblastoma may be mistaken for endodontic pain

Genotoxicity and cytotoxicity effects of X-rays on the oral mucosa epithelium at different fields of view: a cone beam computed tomography technique

Background: Cone beam computed tomography (CBCT) is considered a common examination for dentistry problems. Cellular biology can be affected by exposure to ionizing radiations procedures. In this study, we aimed to assess the genotoxicity and cytotoxicity effects of CBCT dental examinations at two different fields of view (FOVs) in exfoliated buccal epithelial cells. Methods: Sixty healthy adults participated in the current study. They were divided into two identical groups; CBCT with FOV of 6*6 cm2 and 8*11 cm2. Exfoliated oral mucosa cells were prepared immediately before and after 10-12 days of CBCT exposure. The cytological smears were stained with the Papanicolaou technique. The amounts of micronuclei and other cytotoxicity cellular changes (Pyknosis, Karyolysis, and Karyorrhexis) were evaluated. The variables of the parameters before and after CBCT examination in the two investigated FOVs were performed using Wilcoxon test and paired-samples t-test in SPSS software. Results: The micronuclei and other cytotoxic changes parameters before and after CBCT exposure for both FOVs (6*6 and 8*11 cm2) increased significantly (p<0.001). Furthermore, a significant difference (p<0.05) was observed between the investigated parameters at the two FOVs. Notably, the FOV of 8*11 cm2 had more side effects than that of 6*6 cm2. There were no statistically significant among males and females for both FOVs. Conclusion: CBCT examinations of dental disorders would increase the risks of inducing genetic damage. The cytotoxicity and chromosomal damage were considered in males and females in both investigated FOVs (6*6 and 8*11 cm2). In this regard, the use of CBCT must be following the ALARA principle

Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic

Water quality simulation of Dez River in Iran using QUAL2KW model

The considerable increase in the contamination load and the diversity of urban, agricultural, and industrial contaminants more than ever have necessitated the need to understand the process of changes and predict the quality of water resources. In this regard, simulations are considered as important tools. In this research, the water quality of the Dez River (southwest of Iran) was simulated using the QUAL2KW model, which was calibrated using data of June 2013 from four hydrometric stations along the river. The model was validated using the data of February 2017 from the same stations. Water quality was simulated in terms of discharge, temperature, EC, and BOD parameters. The data used for the simulation included daily discharge from the dam, hydraulic properties of the river, locations of contaminant sources, regional meteorological parameters, flow rate, pollution concentrations, and coefficient of dispersion. Simulation results showed that the BOD parameter was close to critical condition at 40 km from Dez Regulating Dam due to the inflow of agricultural wastewater. The RMSE and PBIAS coefficients calculated for the model calibration showed good compatibility (95%) between the observational and predicted data; therefore, the model has good and acceptable accuracy. The impacts of agricultural activities and their contaminants, and the activities of industrial centers around the Dez River were investigated using the above outputs. The river status for EC and BOD parameters was predicted based on a minimum critical discharge scenario with the contamination load available. The results showed that with a discharge of 190 m3/s, the BOD value would be critical in 40 km of the Dez Regulating Dam. The EC value exceeded the permissible value with a discharge of 50 CMS at Bamdaj station that poses a serious threat to the environment

Endodontic Treatment of Fused Teeth with Talon Cusp

Tooth anomalies are rare phenomena that may be reported by patients as chief complaints or may be discovered by dentists in the oral examination. In a few cases, rare anomalies are found together in one mouth. Decision to treat such anomalies depends on whether or not they interfere with function and esthetics and also the patient's preference. In the present case, a 19-year-old male presented with two right maxillary fused central and lateral incisors and a geminated left maxillary central incisor. A talon-like projection was found at the junction site of the fused teeth. His chief complaint was sensitivity to cold at the site of the giant fused tooth. This report describes the process of diagnosis and treatment of the two anomalies according to patient preference and needs

Neurologic Complications of Methanol Poisoning: A Clinicoepidemiological Report from Poisoning Treatment Centers in Tehran, Iran

Background: In this study we sought to investigate clinical findings (with a focus on neurologic effects) and also to analyze outcomes of a series of patients with methanol poisoning admitted to two poisoning treatment centers in Tehran, Iran. Methods: In this prospective cross-sectional study, methanol-poisoned patients admitted to departments of forensic medicine and toxicology of Loghman Hakim and Baharloo hospitals in Tehran during October 2010 to October 2011 were included; and their data were recorded in predesigned checklists. Results: Twenty-eight methanol poisoned patients (82.1% men) with mean age of 29.3±4.6 years were studied. Most patients (67.9%) had metabolic acidosis at presentation. On admission, all patients had different degrees of decrease in consciousness, who the majority of them (57.1%) were admitted with mildly reduced consciousness (grade I of Grady coma scale). Headache and vertigo were observed in 7.1% and 17.9% of patients, respectively. Most patients (53.6%) had no ocular effects, while 46.6% of patients developed impaired vision. All patients received sodium bicarbonate. Ethanol as antidote and folic acid were given to 18 patients (64.2%) and 16 patients (57.1%), respectively. Six patients (21.4%) underwent hemodialysis. Over half of the patients (53.6%) fully recovered and were discharged without complications. Four patients (14.3%) developed total blindness. Four patients (14.3%) left the hospital against medical advice by self-discharge (they had no significant complication at the time of discharge). Five patients (17.9%) died; who compared to survived cases had significantly lower blood pH (P=0.028), higher coma grade (

Chaos-based multigene genetic programming: a new hybrid strategy for river flow forecasting

Chaos theory is integrated with Multi-Gene Genetic Programming (MGGP) engine as a new hybrid model for river flow forecasting. This is to be referred to as Chaos-MGGP and its performance is tested using daily historic flow time series at four gauging stations in two countries with a mix of both intermittent and perennial rivers. Three models are developed: (i) Local Prediction Model (LPM); (ii) standalone MGGP; and (iii) Chaos-MGGP, where the first two models serve as the benchmark for comparison purposes. The Phase-Space Reconstruction (PSR) parameters of delay time and embedding dimension form the dominant input signals derived from original time series using chaos theory and these are transferred to Chaos-MGGP. The paper develops a procedure to identify global optimum values of the PSR parameters for the construction of a regression-type prediction model to implement the Chaos-MGGP model. The inter-comparison of the results at the selected four gauging stations shows that the Chaos-MGGP model provides more accurate forecasts than those of stand-alone MGGP or LPM models.No sponso

Evaluation of the anterior maxillary bone for implant placement and its relationship with the final restoration using Cone Beam Computed Tomography (CBCT) images

Statement of the Problem: The thickness and height of the facial wall of the alveolar bone in anterior part of maxilla is a critical factor to achieving esthetic and success of   implant insertion. Objectives:The aim of  present study was evaluating the anterior maxillary bone by cone beam computed tomography (CBCT) images.Methods :In this in vitro study, 200 CBCT images of the anterior maxillary teeth were examined. Each tooth was classified according to the sagittal root position and the measurements were done by one practitioner. Results:The following variables were significantly associated with gender (male predilection): tooth-ridge angulation (TRA )in the right lateral teeth; concavity angulation (CA)in the right central and lateral teeth; concavity depth (CD ) in the right lateral teeth and both canines; concavity location (CL)in the right canine; buccal bone height (BH)and palatal bone height ( PH) in the left canine.Age was associated with CLand ridge angulation in none of the teeth; with TRA and CD in all anterior teeth; bone density in the right lateral teeth; with CA in both  lateral teeth; with BH in both central teeth; with PHin the right central and left lateral teeth; and with TA in both lateral teeth and canines.&nbsp