Second Molar Uprighting with Temporary Anchorage Devices: A Finite Element Study

BACKGROUND AND OBJECTIVE: Premature loss of mandibular first molar is a common problem in adults. Mesial tipping of second molar may occur in this situation. Various orthodontic mechanics have been proposed for molar uprighting. The aim of this study was to compare four methods of molar uprighting using Finite Element Analysis(FEM). METHODS: In first model of this finite element study, a 0.019×0.025 inch beta-titanium segmental arch wire with a T-loop was used. In second model a miniscrew was inserted in retromolar space and force was applied using elastomeric chain. The third model was a piece of 0.016×0.022inch beta-titanium wire with a bend which was placed more occlusal than the screw. The fourth model contained a mesially inserted miniscrew with an angle of 70 degrees to bone surface and a 0.018×0.025inch beta-titanium wire with helix. Extrusion, center of rotation and stress distribution in PDL during movement was compared between methods. FINDINGS: Buccal cusp extruded 1.36E-03, 1.13E-03, -9.74E-04 and 1.49E-03 mm in first, second, third and fourth model, respectively. Similarly, in lingual cusp, the amount of vertical displacement was at least in third model (-6.83E-04 mm). This amount in second and first method was 1.12E-03 and 4.05E-04 mm, respectively. The maximum amount of extrusion of lingual cusp occurred in fourth model (9.01E-03 mm). Mesial and distal cusps extruded 2.12E-04 and 1.58E-03 mm in first model, -1.14E-03 and 3.80E-03 mm in second method, -2.37E-03 and 7.04E-04 mm in third design and, 1.88E-03 and 8.57E-03 mm in the fourth model. The center of rotation was located at molar bifurcation in third model. CONCLUSION: The maximum amount of extrusion in both mesiodistal and buccolingual path was seen in fourth model. The best type of movement was found in third model, in which minimum extrusion occurred and center of rotation located at molar bifurcation

The Effect of Different Methods of Fluoride Administration at Different Concentrations on the Load-Deflection Properties of Rhodium-Coated Niti Archwires

Background and Objective: Fluoride compounds are widely used for the control of dental plaque. Considering the effect of different fluoride compounds on the mechanical properties of orthodontic wires, this study was conducted to analyze the effect of different methods of fluoride administration at different concentrations on the load-deflection properties of rhodium-coated NiTi orthodontic archwires. Methods: This clinical trial was conducted on 30 patients aged between 15 and 25 years referring to Babol University of Medical Sciences due to dental crowding and didn't have vertical skeletal defects. 0.016-inch Rhodium-Coated A-NiTi wire was placed on patients' maxillary brackets. Patients were randomly divided into three groups of ten: The control group used only fluoride toothpaste, the second group used fluoride toothpaste with sodium fluoride mouthwash (0.05%) and the third group used fluoride toothpaste with Acidulated Phosphate Fluoride gel (1.23% APF). After six weeks, the values of unloading force (N), yield strength (N/m2) and stiffness (N/m) of the wires were obtained using a three-point bending test. Findings: The mean unloading force and stiffness of the second group wires were higher than that of the other groups and in the first group, they were higher than the control group in all values, but no significant differences were found between the groups. There was a significant difference between the yield strengths of different groups (p=0.038). The mean yield strength in the second group was higher than the other groups (0.94±0.16 N/m2) and was significantly different from the control group (0.75±0.19 N/m2) (p=0.030). Conclusion: According to this study, method of fluoride administration does not affect the unloading force and stiffness but the yield strength of rhodium-coated NiTi archwires increases with an increase in the fluoride concentration

Response to the Bam Earthquake: A Qualitative Study on the Experiences of the Top and Middle Level Health Managers in Kerman, Iran

Introduction: The 2003 Bam, Iran earthquake resulted in high casualties and required international and national assistance. This study explored local top and middle level managers’ disaster relief experiences in the aftermath of the Bam earthquake. Methods: Using qualitative interview methodology, top and middle level health managers employed during the Bam earthquake were identified. Data were collected via in-depth interviews with participants. Data were analysed using thematic analysis. Results: Results showed that the managers interviewed experienced two main problems. First, inadequacy of preparation of local health organisations, which was due to lack of familiarity of the needs, unavailability of essential needs, and also increasing demands, which were above the participants’ expectations. Second, inappropriateness of delivered donations was perceived as a problem; for example, foods and sanitary materials were either poor quality or expired by date recommended for use. Participants also found international teams to be more well-equipped and organised. Conclusions: During the disaster relief period of the response to the Bam earthquake, local health organizations were ill prepared for the event. In addition, donations delivered for relief were often poor quality or expired beyond a usable date

Ascending aortic aneurysm and aortic valve dysfunction in bicuspid aortic valve disease

BACKGROUND: The relationship of aortic valve dysfunction and ascending aortic aneurysm is unclear in adults with bicuspid aortic valve disease. METHODS: We retrospectively studied 134 consecutive out-patients (98 men, 36 women aged 43+/-18years) with bicuspid aortic valve disease. To investigate the relationship of ascending aortic aneurysm and aortic valve dysfunction we exclusively considered severe pathologies that required treatment by surgical or percutaneous intervention. RESULTS: Of 134 patients, 39 had aortic valve dysfunction without concomitant ascending aortic aneurysm which had been treated previously with isolated valve surgery or percutaneous valvuloplasty comprising 25 patients with aortic stenosis (19%) and 14 patients with aortic regurgitation (10%). Conversely, 26 patients had ascending aortic aneurysm which had been treated previously with aortic surgery (19%). Of these, ascending aortic aneurysm was associated with severe aortic stenosis in 13 patients and with severe aortic regurgitation in 7 patients, whereas aneurysm was unrelated to severe aortic valve dysfunction in the remaining 6 patients including 2 without any degree of aortic valve dysfunction. The maximal aortic diameters were similar at the time of aortic surgery irrespective of presence of severe aortic valve dysfunction (P=.527). Other characteristics of patients with ascending aortic aneurysm were also similar irrespective of presence or type of aortic valve dysfunction. CONCLUSION: The majority of patients with bicuspid aortic valve disease exhibit ascending aortic aneurysm in conjunction with severe aortic valve dysfunction. However, in our study 6 of 134 (5%) of persons with bicuspid aortic valve disease developed ascending aortic aneurysm without aortic valve dysfunction

Pathologist Concordance for Ovarian Carcinoma Subtype Classification and Identification of Relevant Histologic Features Using Microscope and Whole Slide Imaging.

CONTEXT.—: Despite several studies focusing on the validation of whole slide imaging (WSI) across organ systems or subspecialties, the use of WSI for specific primary diagnosis tasks has been underexamined. OBJECTIVE.—: To assess pathologist performance for the histologic subtyping of individual sections of ovarian carcinomas using a light microscope and WSI. DESIGN.—: A panel of 3 experienced gynecologic pathologists provided reference subtype diagnoses for 212 histologic sections from 109 ovarian carcinomas based on optical microscopy review. Two additional attending pathologists provided diagnoses and also identified the presence of a set of 8 histologic features important for ovarian tumor subtyping. Two experienced gynecologic pathologists and 2 fellows reviewed the corresponding WSI images for subtype classification and feature identification. RESULTS.—: Across pathologists specialized in gynecologic pathology, concordance with the reference diagnosis for the 5 major ovarian carcinoma subtypes was significantly higher for a pathologist reading on a microscope than each of 2 pathologists reading on WSI. Differences were primarily due to more frequent classification of mucinous carcinomas as endometrioid with WSI. Pathologists had generally low agreement in identifying histologic features important to ovarian tumor subtype classification with either an optical microscopy or WSI. This result suggests the need for refined histologic criteria for identifying such features. Interobserver agreement was particularly low for identifying intracytoplasmic mucin with WSI. Inconsistencies in evaluating nuclear atypia and mitoses with WSI were also observed. CONCLUSIONS.—: Further research is needed to specify the reasons for these diagnostic challenges and to inform users and manufacturers of WSI technology

a controlled multicenter study with assessment of echocardiographic reference values, and the frequency of dilatation and aneurysm in Marfan syndrome

Background Echocardiographic upper normal limits of both main pulmonary artery (MPA) diameters (MPA-d) and ratio of MPA to aortic root diameter (MPA-r) are not defined in healthy adults. Accordingly, frequency of MPA dilatation based on echocardiography remains to be assessed in adults with Marfan syndrome (MFS). Methods We enrolled 123 normal adults (72 men, 52 women aged 42 ± 14 years) and 98 patients with MFS (42 men, 56 women aged 39 ± 14 years) in a retrospective cross-sectional observational controlled study in four tertiary care centers. We defined outcome measures including upper normal limits of MPA-d and MPA-r as 95 quantile of normal persons, MPA dilatation as diameters > upper normal limits, MPA aneurysm as diameters >4 cm, and indication for surgery as MPA diameters >6 cm. Results MPA diameters revealed normal distribution without correlation to age, sex, body weight, body height, body mass index and body surface area. The upper normal limit was 2.6 cm (95% confidence interval (CI) =2.44-2.76 cm) for MPA-d, and 1.05 (95% CI = .86–1.24) for MPA-r. MPA dilatation presented in 6 normal persons (4.9%) and in 68 MFS patients (69.4%; P < .001), MPA aneurysm presented only in MFS (15 patients; 15.3%; P < .001), and no patient required surgery. Mean MPA-r were increased in MFS (P 1.05 were equally frequent in 7 normal persons (5%) and in 8 MFS patients (10.5%; P = .161). MPA-r related to aortic root diameters (P = .042), reduced left ventricular ejection fraction (P = .006), and increased pulmonary artery systolic pressures (P = .040). No clinical manifestations of MFS and no FBN1 mutation characteristics related to MPA diameters. Conclusions We established 2.6 cm for MPA-d and 1.05 for MPA-r as upper normal limits. MFS exhibits a high prevalence of MPA dilatation and aneurysm. However, patients may require MPA surgery only in scarce circumstances, most likely because formation of marked MPA aneurysm may require LV dysfunction and increased PASP

Cross-sectional associations between occupational factors and musculoskeletal pain in women teachers, nurses and sonographers

A. Technical measurements of the physical workload. (DOCX 18 kb