23 research outputs found

    Correlation of Mandibular Second Molar Impaction with Third Molar Size, Angulation, Developmental Stage, and Bud Position

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    Objective: The present study assessed the association of size, axial angulation, developmental stage and bud position of the mandibular third molar with the second molar impaction in patients with mandibular second molar impaction.Methods: In this descriptive-analytical study (Case-Control Design), dental records of 5,420 patients in the age range of 12-15 years who underwent orthodontic treatment were assessed out of which 20 patients (14 females and 6 males) with lower second molar impaction were studied. Twenty control patients with erupted second molars were selected from the same centers and matched with the case group. Total sample size was 40 (Case and Control) and had normal distribution for the determined measurements. Third molar axial angulation towards the second molar, first molar and mandibular base, mesiodistal width of 3rd molar /2nd molar ratio, Nolla developmental stage and third molar bud position were measured and calculated in patients with impacted and erupted second molars and analyzed using student t and chi-square tests.Results: The mean degree of third molar angulation towards the second molar, first molar and mandibular base was 30.20, 53.6, and 51.3 degrees in cases and 21.4, 34.65 and 45.15 degrees in controls, respectively. Significant differences were found between the two groups in terms of third molar angulation towards the second molar (30.2 Vs 21.4 degrees p<0.047), and first molar (53.6 Vs34.65 degrees p<0.0001); while no differences were found between the two groups in terms of third molar angulation towards the mandibular base (51.3 Vs 45.15 degrees). The mean mesiodistal width of third molar/ second molar ratio was 0.99 in cases and 0.95 in controls with no significant difference. Nolla developmental stage and position of the marginal ridge of the third molar bud towards the second molar showed no definite relation with second molar impaction.Conclusion: It seems that angulation of third molar to the second and first molars is a major contributing factor to increase the risk of second molar impaction. Third molars size, developmental stages, and bud positions, do not show a significant relation to the second molar impaction

    Enamel Surface Roughness after Orthodontic Bracket Debonding and Composite Resin Removal by Two Types of Burs

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    Objective: Increased enamel surface roughness following orthodontic bracket debonding leads to increased plaque accumulation and enamel decalcification. Therefore, different methods are employed to achieve smoother enamel surfaces after bracket debonding. This study  compared enamel surface roughness following orthodontic bracket debonding and composite resin removal using white stone and tungsten carbide burs.Methods: In this in-vitro, experimental study, 20 first and second premolars of 10-20 year-olds were collected and their crowns were mounted in acrylic blocks. Roughness of the buccal surfaces of teeth was determined by atomic force microscopy (AFM) and the brackets were bonded to the teeth. After bracket debonding, composite remnants were removed using white stone and tungsten carbide burs. Parameters of enamel surface roughness were determined by AFM and time required for composite removal was also calculated. Repeated measures ANOVA was used to assess the changes in parameters based on the time of measurement, type of bur and their interaction effect. Time required for composite resin removal by bur was analyzed using one-way ANOVA and Tukey’s multiple comparisons.Results: Resin removal increased enamel surface roughness compared to the baseline values in all groups. However, no significant differences were noted between the two types of burs regarding arithmetic average of the roughness profile (Ra), the root mean square roughness (Rq) and the maximum peak-to-valley height in the sampling length (Rt) after resin removal. Time required for resin removal with tungsten carbide bur (34.2 seconds) was significantly shorter than with white stone bur (56.6 seconds)(both ps<0.0001).Conclusion: Considering the similar enamel surface roughness values achieved by the two burs, tungsten carbide burs are recommended for resin removal following orthodontic bracket debonding

    Exploring the Behaviors of Tourists at Historical Sites Vandalism or Expression of Attachment Toward Place (A Case Study of Written Words on Si-o-Se-Pol Bridge)

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    Some tourists etch their names on the walls of historical buildings as a permanent mark without any significance. Sociologists refer to these individuals as vandals. This study discusses this topic from the perspective of environmental psychology and assumes that these scribbled written words are one of the signs of attachment to a place. Therefore, the research aims at examining the reasons why such behaviors occur to take a step towards controlling, reducing, and preventing destruction by tourists by writing or inscribing words. For this purpose, this research attempted to answer two questions: What motivates some tourists to leave written words on historical sites and monuments (such as the Si-o-se-pol bridge)? Which vandalistic motivations or sense of attachment to the place dominates this bridge? To analyze the data, the written words were categorized into groups (A.B.C.D), and a visible sense of attachment was observed in all of these groups. Qualitative content analysis was used to uncover hidden meanings. After studying the remaining written words on the bridge walls, semi-structured interviews (open-response) were carried out with vandal tourists. The results indicate that the written words are driven by a sense of attachment to the place. According to theoretical definitions, this type of behavior, recording memories with a name and date, reflects the feelings of people who have visited the place repeatedly

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Comparative immunomodulatory properties of adipose-derived mesenchymal stem cells conditioned media from BALB/c, C57BL/6, and DBA mouse strains

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    Adipose tissue-derived mesenchymal stem cells (AD-MSCs) have been shown to be capable of differentiating into multiple cell type and exert immunomodulatory effects. Since the selection of ideal stem cell is apparently crucial for the outcome of experimental stem cell therapies, therefore, in this study we compared AD-MSCs conditioned media (CM) from BALB/c, C57BL/6, and DBA mouse strains. No significant difference was found in the morphology, cell surface markers, in vitro differentiation and proliferation potentials of AD-MSCs isolated from C57BL/6, BALB/c, and DBA mice. The immunological assays showed some variation among the strains in the cytokines, nitric oxide (NO), and indoleamine 2,3-dioxygenase (IDO) production and immunomodulatory effects on splenocytes functions. Our results indicated a suppression of splenocytes proliferation in the presence of AD-MSC CM from the three inbred mouse strains. However, BALB/c CM exerted a higher suppression of splenocytes proliferation. AD-MSCs isolated from C57BL/6 and BALB/c mice produced higher levels of TGF-β than those from DBA mice. Furthermore, IL-17 and IDO production was higher in AD-MSCs isolated from BALB/c mice. Our results indicated an increased production of TGF-β, IL-4, IL-10, NO, and IDO by splenocytes in response to CM from BALB/c AD-MSCs. In conclusion, our results showed that the immunomodulatory properties of mouse AD-MSCs is strain-dependent and this variation should be considered during selection of appropriate stem cell source for in vivo experiments and stem cell therapy strategies

    In vitro immunomodulatory properties of osteogenic and adipogenic differentiated mesenchymal stem cells isolated from three inbred mouse strains

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    Mesenchymal stem cells (MSCs) are used for cell-based therapies because of their immunomodulatory properties. The immunomodulatory properties of adipogenic (AD) and osteogenic (OS) differentiated adipose tissue-derived MSCs (AD-MSCs) isolated from BALB/c, C57BL/6, and DBA mice were compared. Splenocytes proliferation was suppressed in the presence of AD-MSCs conditioned media in all mice. After OS differentiation, BALB/c AD-MSCs produced higher levels of TGF-β and IL-17 and lower levels of NO than AD-MSCs isolated from C57BL/6 and DBA mice. In addition, OS differentiated AD-MSCs isolated from DBA mice produced lower levels of IL-10 than AD-MSCs isolated from C57BL/6 and DBA mice. After in vitro AD and OD differentiation, AD-MSCs isolated from each mouse produced higher levels of NO and IDO than undifferentiated cells. Additionally, AD-MSCs isolated from C57BL/6 and DBA mice produced higher levels of NO than AD-MSCs isolated from BALB/c mice. Adipose tissue-derived MSCs thus retain their immunomodulatory properties after in vitro OS and AD differentiation in a strain-dependent manner

    Developing a pro-angiogenic placenta derived amniochorionic scaffold with two exposed basement membranes as substrates for cultivating endothelial cells

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    Decellularized and de-epithelialized placenta membranes have widely been used as scaffolds and grafts in tissue engineering and regenerative medicine. Exceptional pro-angiogenic and biomechanical properties and low immunogenicity have made the amniochorionic membrane a unique substrate which provides an enriched niche for cellular growth. Herein, an optimized combination of enzymatic solutions (based on streptokinase) with mechanical scrapping is used to remove the amniotic epithelium and chorion trophoblastic layer, which resulted in exposing the basement membranes of both sides without their separation and subsequent damages to the in-between spongy layer. Biomechanical and biodegradability properties, endothelial proliferation capacity, and in&nbsp;vivo pro-angiogenic capabilities of the substrate were also evaluated. Histological staining, immunohistochemistry (IHC) staining for collagen IV, and scanning electron microscope demonstrated that the underlying amniotic and chorionic basement membranes remained intact while the epithelial and trophoblastic layers were entirely removed without considerable damage to basement membranes. The biomechanical evaluation showed that the scaffold is suturable. Proliferation assay, real-time polymerase chain reaction for endothelial adhesion molecules, and IHC demonstrated that both side basement membranes could support the growth of endothelial cells without altering endothelial characteristics. The dorsal skinfold chamber animal model indicated that both side basement membranes could promote angiogenesis. This bi-sided substrate with two exposed surfaces for cultivating various cells would have potential applications in the skin, cardiac, vascularized composite allografts, and microvascular tissue engineering

    Evaluation of cytotoxic effects of Anbarnesa on fibroblast L929: Can it be used as a mouthwash?

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    Aims: In Iranian traditional medicine Anbarnesa (derived from smoke from burning female donkey′s stool) has been used to treat ulcers and inflammatory conditions like stomatitis and ear infections (otitis). We assess the properties of Anbarnesa as an alternative mouthwash. Materials and Methods: In this experimental study, Anbarnesa smoke was analyzed using aGC-mass device. The smoke collected was dissolved at different densities in propylene glycol and incubated in Dulbecco′s modified Eagle′s medium in direct contact with fibroblast cells. Assessment of cytotoxicity was done at 1, 24 and 72 h. Cell viability was measured by methyl thiazolyl tetrazolium test, and ELISA Reader machine was used to read the results. Data were analyzed using one-way ANOVA test. Results: The findings of this study showed Anbarnesa was nontoxic in 1/64, 1/128 and 1/256 dilutions. In 1/32 dilution, toxicity was seen after 72 h. In dilutions, 1/8 and 1/16 toxicity were seen in the 1 st h. Conclusion: According to the initial results of Anbarnesa may be used as an alternative mouthwash with fewer side-effects for plaque control and prevention of periodontal disease
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