The largest bilateral gemination of permanent maxillary central incisors: report of a case

Gemination is defined as an attempt to make two teeth from one enamel organ. Bilateral presentation of this phenomenon is very rare, with prevalence of 0.01% to 0.04% in the primary, and 0.05% in the permanent dentition. This paper describes a rare case of huge bilateral gemination of permanent maxillary central incisors in a nine-yearold Iranian boy with poor aesthetic. The patient did not have history of anomaly in his primary dentition and in his family either. This type of dental anomaly can cause clinical problems in the form of malocclusion, poor aesthetic, and impaction of adjacent teeth, caries, and periodontal destruction

MULTIPLE INTELLIGENCES AS PREDICTORS OF READING COMPREHENSION AND VOCABULARY KNOWLEDGE

Abstract: The present study was conducted to investigate types of Multiple Intelligences as predictors of reading comprehension and vocabulary knowledge. To meet this objective, a 60-item TOEFL test and a 90-item multiple intelligences questionnaire were distributed among 240 male and female Iranians studying English at Qazali and Parsian Universities in Qazvin. Data were analyzed using a multiple regression procedure. The result of the data analysis indicated that musical, interpersonal, kinesthetic, and logical intelligences were predicators of reading comprehension. Moreover, musical, verbal, visual, kinesthetic and natural intelligences made significant contributions to predicting vocabulary knowledge.  Key words: Multiple intelligences, reading comprehension, vocabulary knowledge

Introduction to Competing Risk Model in the Epidemiological Research

Background and aims: Chronic kidney disease (CKD) is a public health challenge worldwide, with adverse consequences of kidney failure, cardiovascular disease (CVD), and premature death. The CKD leads to the end-stage of renal disease (ESRD) if late/not diagnosed. Competing risk modeling is a major issue in epidemiology research. In epidemiological study, sometimes, inappropriate methods (i.e. Kaplan-Meier method) have been used to estimate probabilities for an event of interest in the presence of competing risks. In these situations, competing risk analysis is preferred to other models in survival analysis studies. The purpose of this study was to describe the bias resulting from the use of standard survival analysis to estimate the survival of a patient with ESRD and to provide alternate statistical methods considering the competing risk. Methods: In this retrospective study, 359 patients referred to the hemodialysis department of Shahid Ayatollah Ashrafi Esfahani hospital in Tehran, and underwent continuous hemodialysis for at least three months. Data were collected through patient’s medical history contained in the records (during 2011-2017). To evaluate the effects of research factors on the outcome, cause-specific hazard model and competing risk models were fitted. The data were analyzed using Stata (a general-purpose statistical software package) software, version 14 and SPSS software, version 21, through descriptive and analytical statistics. Results: The median duration of follow-up was 3.12 years and mean age at ESRD diagnosis was 66.47 years old. Each year increase in age was associated with a 98% increase in hazard of death. In this study, statistical analysis based on the competing risk model showed that age, age of diagnosis, level of education (under diploma), and body mass index (BMI) were significantly associated with death (hazard ratio [HR] = 0.98, P < 0.001, HR = 0.99, P < 0.001, HR = 2.66, P = 0.008, and HR = 0.98, P < 0.020, respectively). Conclusion: In analysis of competing risk data, it was found that providing both the results of the event of interest and those of competing risks were of importance. The Cox model, which ignored the competing risks, presented the different estimates and results as compared to the proportional sub-distribution hazards model. Thus, it was revealed that in the analysis of competing risks data, the sub-distribution proportion hazards model was more appropriate than the Cox model

Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: a comparison study

Objectives: Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. Study Design: The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in 3 different sizes using round diamond bur and bone chips, respectively. Panoramic radiography, spiral tomography and cone-beam computed tomography were used in defect detection. Data were statistically analyzed with the Mann-Whitney test. The reliability and degrees of agreement between two observers were also determined by the mean of Cohen's Kappa analysis. Results: CBCT had a statistically significant superiority than other studied techniques in detection of both erosive and osteophytic lesions with different sizes. There were significant differences between tomography and panoramic in correct detection of both erosive and osteophytic lesions with 1mm and 1.5 mm in size. However, there were no significant differences between Tomography and Panoramic in correct detection of both erosive and osteophytic lesions with 0.5 mm in size. Conclusions: CBCT images provide a greater diagnostic accuracy than spiral tomography and panoramic radiography in the detection of condylar bone erosions and osteophytes

Comparison of pharyngeal airway volume in different skeletal facial patterns using cone beam computed tomography

This study aimed to compare the pharyngeal airway volume in class I,II and III skeletal malocclusion patients using cone beam computed tomography (CBCT). This retrospective, cross sectional study was conducted on lateral cephalograms of 71 patients derived from their CBCT scans. Using the ANB angle, the patients were divided into class I,II and III malocclusion. Two observers used Dolphin 3D software to calculate the pharyngeal airway volume, airway area, minimum axial area, minimum area location, airway length and morphology. Data were analyzed using one-way ANOVA, Kruskal-Wallis test, Tukey?s test, Spearman?s correlation coefficient and multiple regression analysis. The three skeletal classes were significantly different in airway volume, minimum axial area, mean airway area and airway morphology (P<0.05). Significant differences were found in airway volume and mean airway area between class II and III patients (P<0.05). The minimum axial area and airway morphology in class III patients were greater than those in class I and II patients (P<0.05). Every one unit increase in the ANB angle decreased the airway volume by 0.261 units. The effect of ANB angle on airway volume was statistically significant and it was shown that one unit increase in the angle decreased the airway volume by 453.509 units. A significant correlation exists between the skeletal facial pattern and upper airway dimensions. In our study, the total airway volume and the mean airway area of class III patients were larger than those in class II patients

Causal Layers of Social Dissatisfaction in the Islamic Republic of Iran

IntroductionSocial dissatisfaction in Iran, particularly over the past decade, has been widespread and profound, as confirmed by national surveys. A review of the last four decades reveals the emergence of social discontent and political unrest in various manifestations and at different times. In certain instances, such as in 2009, the protests have posed a threat to the survival and stability of the Islamic Republic of Iran. Indeed, an analysis of the frequency and duration of social protests demonstrates the growth and prevalence of social dissatisfaction within Iranian society.Social dissatisfaction can manifest itself through apathy and non-participation, as seen in the decline in political participation during the Islamic Council and presidential elections in in the recent decade, particularly in 2019 and 2021. A review of relevant research shows a lack of deep insight and comprehensive understanding of social dissatisfaction as a multi-faceted issue in Iran, which can be a major obstacle to insightful policymaking for successful and cost-effective management of social dissatisfaction.The present research aimed to analyze and elucidate the underlying factors that contribute to social dissatisfaction, and subsequently develop strategies for effectively managing and mitigating the issue within Iranian society. The objective can ultimately enhance the efficiency of the decision-making process and policymaking in order to effectively address social dissatisfaction and protests. Accordingly, the main research questions are: What are the causal factors underlying social dissatisfaction in the Islamic Republic of Iran? and what are the potential solutions to solve the issue?Materials and MethodsThe present research employed a mixed methods research design. The documentary analysis method was utilized to examine and analyze various perspectives and approaches, as well as to investigate the evolution of the phenomenon of social dissatisfaction in Iranian society. Moreover, the method of causal layered analysis (CLA) was used to analyze and explain the underlying causes that contribute to social dissatisfaction in Iran.This method incorporates the examination of four distinct layers: the litany, social/systemic causes, discourse/worldview, and myth/metaphor. The litany layer represents the surface level, encompassing the most evident and objective aspects of the future. The social/systemic layer involves exploring the technological, social, economic, historical, political, and environmental causes associated with the subject matter. The discourse layer encompasses efforts to comprehend linguistic, cultural, and social structures that shape and pertain to the future. Lastly, the myth/metaphor layer delves into the investigation and exploration of schemas, mental images, and underlying narratives.The researchers collected the data by administering an open semi-structured questionnaire to a total of 10 experts. The collected data was subjected to review by 5 additional experts, who were asked to confirm the identified causes and related factors with the ultimate aim of ensuring the validity and reliability of the data. Based on the degree of consensus and frequency, the identified causes were categorized into three levels: systemic, discursive, and metaphorical. Furthermore, the researchers developed scenarios of social dissatisfaction by sharing the collected data with 5 experts, who were requested to envision future dissatisfaction scenarios in the 2031 horizon across three categories: desirable, possible, and probable. Results and DiscussionAfter conducting a review of relevant literature and collecting insights from 10 experts, the present study examined and analyzed the causes and factors contributing to social dissatisfaction the Islamic Republic in three layers: systemic, discursive, and metaphorical. At the systemic level, various factors were identified and discussed, including the prevalence of poverty, increasing discrimination, widening class gap and increasing Gini coefficient, evolving societal lifestyles, widespread feelings of deprivation, unjust distribution of national resources, and unsustainable development, etc.In the discursive layer, various causes and factors were identified and analyzed, including the historical mistrust towards the political sphere, the duality of the Islamic Revolution and the Islamic Republic of Iran, the Shia culture and thought, the modern thought and worldview, the discourse of transformation, the discourse of Western development, and the alienation of political governance, etc. Moving to the metaphorical/mythical layer, factors such as the portrayal of the government as a bandit in Iranian culture, the usurpation of power by the state, the metaphor of the Alavi government, and historical transformation-seeking were recognized and discussed as influential elements in the development of social dissatisfaction.Moreover, in accordance with expert opinions, three scenarios (desirable, possible, and probable) were formulated and constructed regarding the future of social dissatisfaction in Iran. In the desirable scenario, effective reformist measures and the realization of the right to protest would lead to a reduction in social dissatisfaction, putting protests within a legally recognized framework. In the possible scenario, considering the continuation and exacerbation of underlying causes of dissatisfaction, we would witness the accumulation of social dissatisfaction and the emergence of intermittent episodes of violent social protests. Finally, according to the probable scenario, civil disobedience would arise as a result of the prevailing security-focused approach and the rising costs of engaging in protests.ConclusionSocial dissatisfaction remains a significant issue in Iran, posing considerable challenges to political stability and national security. Effective policymaking and management concerning social dissatisfaction initially requires a comprehensive and accurate understanding of this complex issue. In this line, the present study used the CLA method as an effective approach to examine different causal layers and drivers and their impact on social dissatisfaction. The results indicated that the Islamic Republic of Iran aims to move towards its desired scenario, which involves reducing dissatisfaction and implementing a persuasive and systematic approach to managing social protests. However, given the current circumstances, attaining this scenario proves to be challenging. Instead, the possible scenario entails the continued accumulation of dissatisfaction and ongoing social protests, which will pose a significant challenge to the political stability of the Islamic Republic of Iran. Protests will be characterized by increased violence, potentially leading the political system to adopt a hard approach in suppressing and managing social unrest. This, in turn, may exacerbate radicalism and further fuel social dissatisfaction. The probable scenario, characterized by intermittent and costly protests as well as civil disobedience, presents an alternative outlook for the future of social dissatisfaction. In this scenario, social dissatisfaction manifests itself through intermittent protests that occur at various intervals and in response to specific events. As social dissatisfaction continues to evolve and persist, some citizens may resort to civil disobedience and divergence from official values and norms

Comparison of the root canal debridement ability of two single file systems with a conventional multiple rotary system in long oval-shaped root canals : in vitro study

This study sought to compare the root canal debridement ability of Neolix, Reciproc and ProTaper rotary systems in long oval-shaped root canals. Eighty five extracted single-rooted human teeth with long oval-shaped single root canals were selected and divided into three experimental groups(n=25) and one control group (n= 10). Root canals were filled with Vitapex radiopaque contrast medium and prepared with Neolix, Reciproc or ProTaper systems. The control group only received irrigation. Digital radiographs were obtained at baseline and postoperatively and subjected to digital subtraction. The percentage of reduction in contrast medium was quantified at 0-5 mm and 5-10 mm distances from the apex. The data were analyzed using one-way ANOVA and t-test. The mean percentage of the contrast medium removed was not significantly different in the 0-5mm segment among the three groups (P=0.6). In the 5-10mm segment a significant difference was found in this regard among the ProTaper and Reciproc groups (P=0.02) and the highest mean percentage of contrast medium was removed by ProTaper. But, difference between ProTaper and Neolix as well as Neolix and Reciproc was not significant. In Neolix (P=0.024) and Reciproc (P=0.002) systems, the mean percentage of the contrast medium removed from the 0-5mm segment was significantly greater than that in 5-10mm segment; however, this difference was not significant in ProTaper group (P=0.069). Neolix single-file system may be a suitable alternative to ProTaper multiple-file system in debridement of long oval shaped canals

Introduction to Competing Risk Model in the Epidemiological Research

Background and aims: Chronic kidney disease (CKD) is a public health challenge worldwide, with adverse consequences of kidney failure, cardiovascular disease (CVD), and premature death. The CKD leads to the end-stage of renal disease (ESRD) if late/not diagnosed. Competing risk modeling is a major issue in epidemiology research. In epidemiological study, sometimes, inappropriate methods (i.e. Kaplan-Meier method) have been used to estimate probabilities for an event of interest in the presence of competing risks. In these situations, competing risk analysis is preferred to other models in survival analysis studies. The purpose of this study was to describe the bias resulting from the use of standard survival analysis to estimate the survival of a patient with ESRD and to provide alternate statistical methods considering the competing risk. Methods: In this retrospective study, 359 patients referred to the hemodialysis department of Shahid Ayatollah Ashrafi Esfahani hospital in Tehran, and underwent continuous hemodialysis for at least three months. Data were collected through patient’s medical history contained in the records (during 2011-2017). To evaluate the effects of research factors on the outcome, cause-specific hazard model and competing risk models were fitted. The data were analyzed using Stata (a general-purpose statistical software package) software, version 14 and SPSS software, version 21, through descriptive and analytical statistics. Results: The median duration of follow-up was 3.12 years and mean age at ESRD diagnosis was 66.47 years old. Each year increase in age was associated with a 98% increase in hazard of death. In this study, statistical analysis based on the competing risk model showed that age, age of diagnosis, level of education (under diploma), and body mass index (BMI) were significantly associated with death (hazard ratio [HR]=0.98, P<0.001, HR=0.99, P<0.001, HR=2.66, P=0.008, and HR=0.98, P<0.020, respectively). Conclusion: In analysis of competing risk data, it was found that providing both the results of the event of interest and those of competing risks were of importance. The Cox model, which ignored the competing risks, presented the different estimates and results as compared to the proportional sub-distribution hazards model. Thus, it was revealed that in the analysis of competing risks data, the sub-distribution proportion hazards model was more appropriate than the Cox model

Adapting BRSQ to assess coach's perception of athletes' motivation : Internal structure analysis

This study was aimed to adapt the Behavioral Regulation in Sport Questionnaire to assess coach's perception of athletes' motivation in a sample of 153 Spanish coaches of both genders. This questionnaire is made up of 24 items that measure the behavioral regulation factors expected by the self-determination theory developed by Deci and Ryan. Results showed that a model of four factors provided the best fit to the data in the confirmatory factor analysis. The factors were: (1) intrinsic regulation, (2) integrated regulation, (3) identified regulation, (4) controlled regulation. Three out of four subscales have acceptable internal consistency coefficients. The accumulation of evidence leads to the conclusion that this version of BRSQ shows an internal structure according to the theoretical predictions, and the autonomous regulation factors show discriminant validity whereas the controlled regulations form a single factor

Fungicidal effect of Origanum vulgare essential oil against Candida glabrata and its cytotoxicity against macrophages

Introduction: Candida glabrata is a yeast fungus regularly isolated from patients with impaired immunity who receive a routine antifungal therapy. Drug-resistant strains of C. glabrata have been emerged in recent years. The aim of this study was to examine the therapeutic efficacy Origanum vulgare essential oil (OVEO) against drug-resistant strains of C. glabrata and its cytotoxic effect on macrophages.Methods: Specimens were collected from mucosal surfaces of the oral cavity of medically approved oropharyngeal candidiasis (OPC) in HIV-positive patients and volunteered healthy individuals using sterile swabs or mouthwashes. In vitro antifungal susceptibility testing was done using microdilution and disc diffusion methods. Chemical composition of OVEO was determined using gas chromatography mass spectrometry. The cytotoxic effect of essential oil on macrophages was examined using tetrazolium dye (MTT).Results: Minimum inhibitory concentration (MIC) range of OVEO in healthy individuals and OPC patients was 150-200 and 150-250 &mu;g/mL, respectively. OVEO efficiently inhibited growth of resistant isolates. In isolates obtained from HIV patients, both MIC50 and MIC90 of OVEO were 200 &mu;g/mL while in healthy individuals were 150 and 200 &mu;g/mL, respectively. Moreover, OVEO induced significant reduction in proliferation of murine RAW264.7 and peritoneal macrophages in concentrations higher than 100 and 300 &mu;g/mL, respectively. Main constituents of OVEO were thymol (27.3), &gamma;-terpinene (20.7) and carvacrol (16.1).Conclusion: OVEO could be used as a fungicidal agent against fungal infections caused by azole-resistant C. glabrata. A combination therapy along with standard antifungals is suggested to avoid its cytotoxic effects.</p