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Summary Objective This study aimed to assess the relationship of the anteroposterior position of maxillary central incisors with the forehead in an Iranian subpopulation residing in Kermanshah city. Materials and methods In this cross-sectional study, 12 orthodontists were requested to analyse full-smile profile photographs with complete maxillary incisor and forehead show in 70 patients with optimal facial harmony (35 males and 35 females) as the control group and 140 patients without optimal facial harmony (70 males and 70 females) as the test group. The inclusion criteria were (I) males and females between 18–60 years seeking orthodontic treatment and (II) willingness for participation in the study. The exclusion criteria were (I) presence of severe craniofacial anomalies, and (II) history of orthodontic treatment. The photographs were traced and analysed using Digimizer Image Analysis software 5.3.5. Data were analysed using STATA version 14.2 via independent t-test and linear regression. Results A significant difference existed in the anteroposterior position of maxillary incisors in males between the test and control groups (P = 0.002). However, this difference was not significant in females of the two groups (P = 0.77). A significant difference was noted in the anteroposterior position of maxillary incisors between males and females in the test group (P = 0.001) but not in the control group (P = 0.80). The frontal angle had a significant correlation with gender and anteroposterior position of maxillary incisors in both groups (P Conclusions According to the results, the anteroposterior position of maxillary incisors was significantly different in the test and control groups. The maxillary incisors in males were more retruded than in females. Also, the frontal angle had a significant correlation with the anteroposterior position of maxillary incisors, and by 1° increase in the frontal angle, the incisors were protruded by averagely 0.307 mm.

BACKGROUND Calcium hydroxide, due to its favorable properties, such as an antimicrobial effect as well as its ability to dissolve necrotic tissues, inhibit tooth resorption and stimulate the formation of a hard tissue barrier, is widely used in root canal treatment. OBJECTIVES The objective of this study was to compare the efficacy of 3 methods of delivery of calcium hydroxide into the canals. MATERIAL AND METHODS This in vitro experimental study was performed on acrylic resin blocks with simulated curved canals (curvature of 24° and 44°). Calcium hydroxide was delivered into the canals with 3 different instruments : a hand file, a Lentulo and a rotary file. The data was analyzed using the three-way analysis of variance (ANOVA) and Tukey's test. RESULTS The density of calcium hydroxide was significantly different among the 3 groups (p < 0.001). The manual delivery technique resulted in the lowest and using a rotary file in the highest density of calcium hydroxide (p < 0.001). The mean density of calcium hydroxide was significantly higher in the canals with curvature of 24°, irrespective of the delivery method (p < 0.001). The lowest mean density of calcium hydroxide was noted at 1 mm and 3 mm from the apex, whereas the highest mean density was noted at 11 mm from the apex, irrespective of delivery method (p < 0.001). CONCLUSIONS A rotary file seems to be the most efficient instrument for delivering calcium hydroxide into the canals, especially into the apical region of canals with greater curvature.

Background This study aimed to compare the effect of virtual and traditional education on theoretical knowledge and reporting skills of dental students in radiographic interpretation of bony lesions of the jaw. Methods This experimental study evaluated 39 dental students who had not received any instruction regarding radiographic interpretation of bony lesions of the jaw. They were randomly divided into two groups of virtual (n = 20) and traditional education (n = 19) and matched in terms of their grade point average (GPA). The virtual group received a virtual learning package while the traditional group received traditional classroom instruction for 6 one-hour sessions. Similar contents were taught to both groups by the same mentor. All students participated in a theoretical test with multiple-choice questions and an objective structured clinical examination (OSCE). Similar exams were also held 2 months later to assess knowledge retention. Data were analyzed using independent sample t-test and repeated measures ANOVA. Results The mean scores of theoretical test (P 0.05) in the virtual education group (16.60 ± 0.91 and 15.13 ± 0.78) were higher than those in the traditional education group (14.89 ± 0.99 and 14.71 ± 0.92). In both methods of instruction, the mean scores of theoretical test and OSCE at 2 months were lower than the scores acquired immediately after instruction but this difference was not statistically significant (P > 0.05). Type of education had a significant effect on the theoretical test score (P

Cardiac hemosiderosis is the primary factor to derive the pathogenesis of cardiac dysfunction in patients with transfusion dependent thalassemia. Biomarkers assessment along with T2 * MRI study could be employed to evaluate the severity of iron deposition-related damage and determination of the diagnostic and prognostic value of these inflammatory factors. The study was conducted on 62 patients (12–44 years old) with major thalassemia. The patients were under regular blood transfusion and they had no signs of cardiac defects, and chronic diseases. The serum levels of inflammatory factors (NT-proBNP, CRP, Copeptin HS) were determined before routine transfusion. Cardiac iron overload was assessed by T2* MRI (within the last three months), and T2* lower than 20 ms was considered as cardiac siderosis. The obtained results were analyzed using statistical methods. 92% of patients showed an increased level of hs-CRP (> 2 µg/dL). All cases showed increased levels of NT-proBNP (> 150 pg/mL). Only 29% of subjects showed high level of Copeptin, 25.8% of patients demonstrated cardiac siderosis based on the T2* MRI (

Objective: The purpose of the present study was to compare mandibular vertical asymmetry in patients with unilateral and bilateral cleft lip and palate and subjects with normal occlusion. Materials and Methods: Cone beam computed tomography scans of three groups consisting of 20 patients with unilateral cleft lip and palate, 20 patients affected by bilateral cleft lip and palate, and a control group of 20 subjects with normal occlusion were analyzed for this study. Condylar, ramal, and condylar plus ramal asymmetry indices were measured for all subjects using the method of Habets et al. Kruskal-Wallis and Mann-Whitney tests were used to determine any significant differences between the groups for all indices at the 95% level of confidence. Results: There were no significant differences regarding sex for all mandibular asymmetry indices in all three groups. All Asymmetry indices (condylar, ramal, and condylar plus ramal asymmetry) were significantly higher in the unilateral cleft group compared with the other two groups. Conclusion: Cone beam computed tomography images showed that patients with cleft lip and palate suffered from mandibular asymmetry. Subjects with unilateral cleft lip and palate had a more asymmetric mandible compared with the bilateral cleft lip and palate and control groups. Therefore, the mandible appears to be the leading factor in facial asymmetry in subjects with unilateral cleft lip and palate.

Adequate knowledge about the position of mental foramen in different populations is imperative for successful anesthetic and surgical interventions. This study sought to assess the vertical and horizontal position of the mental foramen in a subpopulation of Kermanshah city using panoramic radiographs. This cross-sectional study was performed on 500 panoramic radiographs (250 males, 250 females) retrieved from the archives of the oral and maxillofacial radiology clinics in Kermanshah city. The horizontal position of mental foramen was classified according to the classification by Chkoura and El-Wady (6 types). To determine its vertical position, a line was drawn from the center of the mental foramen perpendicular to the inferior border of the mandible and continued to reach the alveolar crest. This distance was divided into four equal segments and the position of mental foramen in each segment was recorded. Data were analyzed using chi-squared, Fisher’s exact and Monte Carlo chi-square tests (P99%). Type 4 (in alignment with the apex of the second premolar) was the most common horizontal position of mental foramen on both sides (>50%). Mental foramen positioned between the apices of the first and second premolars ranked second in terms of frequency (seen in about one-third of the cases). The position of mental foramen was almost the same in males and females, and symmetrical in the right and left sides (73%). Our findings highlighted the variability in the position of mental foramen in a subpopulation of Kermanshah city, which should be taken into account in dental practice.

Background This study aimed to assess the efficacy of a 980-nm diode and 10.6-μm CO2 laser accompanied by tricalcium phosphate-5% sodium fluoride (fTCP) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) for the remineralization of primary teeth. Methods In total, 117 extracted primary anterior teeth were randomly divided into eight experimental and one control group: (I) control (polished enamel), (II) fTCP varnish, (III) fTCP + diode laser, (IV) fTCP + CO2 laser, (V) CPP-ACP, (VI) CPP-ACP + diode laser, (VII) CPP-ACP + CO2 laser, (VIII) diode laser, and (IX) CO2 laser. The microhardness of 12 samples in each group and the enamel porosity of one sample in each group were assessed before and after demineralization and 28 days after remineralization. Data were analysed using two-way ANOVA. Results Significant differences existed in microhardness (P = 0.004) and percentage of remineralization (P 0.05). Conclusion The highest microhardness was achieved after remineralization with CPP-ACP. The efficacy of the diode and CO2 lasers was the same. No synergistic effect was found between materials and lasers. Trial registration This is not a human subject research.

Background This study aimed to assess the efficacy of a 980-nm diode and 10.6-μm CO2 laser accompanied by tricalcium phosphate-5% sodium fluoride (fTCP) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) for the remineralization of primary teeth. Methods In total, 117 extracted primary anterior teeth were randomly divided into eight experimental and one control group: (I) control (polished enamel), (II) fTCP varnish, (III) fTCP + diode laser, (IV) fTCP + CO2 laser, (V) CPP-ACP, (VI) CPP-ACP + diode laser, (VII) CPP-ACP + CO2 laser, (VIII) diode laser, and (IX) CO2 laser. The microhardness of 12 samples in each group and the enamel porosity of one sample in each group were assessed before and after demineralization and 28 days after remineralization. Data were analysed using two-way ANOVA. Results Significant differences existed in microhardness (P = 0.004) and percentage of remineralization (P 0.05). Conclusion The highest microhardness was achieved after remineralization with CPP-ACP. The efficacy of the diode and CO2 lasers was the same. No synergistic effect was found between materials and lasers. Trial registration This is not a human subject research.

Background Two-dimensional projection radiographs have been traditionally considered the modality of choice for cephalometric analysis. To overcome the shortcomings of two-dimensional images, three-dimensional computed tomography (CT) has been used to evaluate craniofacial structures. However, manual landmark detection depends on medical expertise, and the process is time-consuming. The present study was designed to produce software capable of automated localization of craniofacial landmarks on cone beam (CB) CT images based on image registration and to evaluate its accuracy. Methods The software was designed using MATLAB programming language. The technique was a combination of feature-based (principal axes registration) and voxel similarity-based methods for image registration. A total of 8 CBCT images were selected as our reference images for creating a head atlas. Then, 20 CBCT images were randomly selected as the test images for evaluating the method. Three experts twice located 14 landmarks in all 28 CBCT images during two examinations set 6 weeks apart. The differences in the distances of coordinates of each landmark on each image between manual and automated detection methods were calculated and reported as mean errors. Results The combined intraclass correlation coefficient for intraobserver reliability was 0.89 and for interobserver reliability 0.87 (95% confidence interval, 0.82 to 0.93). The mean errors of all 14 landmarks were

Background The importance of using technologies such as e-learning in different disciplines is discussed in the literature. Researchers have measured the effectiveness of e-learning in a number of fields. Considering the lack of research on the effectiveness of online learning in dental education particularly in Iran, the advantages of these learning methods and the positive university atmosphere regarding the use of online learning. This study, therefore, aims to compare the effects of two methods of teaching (virtual versus traditional) on student learning. Methods This post-test only design study approached 40, fifth year dental students of Shiraz University of Medical Sciences. From this group, 35 students agreed to participate. These students were randomly allocated into two groups, experimental (virtual learning) and comparison (traditional learning). To ensure similarity between groups, we compared GPAs of all participants by the Mann–Whitney U test (P > 0.05). The experimental group received a virtual learning environment courseware package specifically designed for this study, whereas the control group received the same module structured in a traditional lecture form. The virtual learning environment consisted of online and offline materials. Two identical valid, reliable post-tests that consisted of 40 multiple choice questions (MCQs) and 4 essay questions were administered immediately (15 min) after the last session and two months later to assess for knowledge retention. Data were analyzed by SPSS version 20. Results A comparison of the mean knowledge score of both groups showed that virtual learning was more effective than traditional learning (effect size = 0.69). Conclusion The newly designed virtual learning package is feasible and will result in more effective learning in comparison with lecture-based training. However further studies are needed to generalize the findings of this study.