Does head tilt influence facial appearance more than head turn?

Purpose: To evaluate the frequency of facial asymmetry parameters in patients with head tilt versus those with head turn. Methods: This cross-sectional comparative study was performed on 155 cases, including 58 patients with congenital pure head turn due to Duane retraction syndrome (DRS), 33 patients with congenital pure head tilt due to upshoot in adduction or DRS, and 64 orthotropic subjects as the control group. The facial appearance was evaluated by computerized analysis of digital photographs of patients' faces. Relative facial size (the ratio of the distance between the external canthus and the corner of the lips of both face sides) and facial angle (the angular difference between a line that connects two external canthi and another line that connects the two corners of the lips) measured as quantitative facial parameters. Qualitative parameters were evaluated by the presence of one-sided face, cheek, and nostril compression; and columella deviation. Results: The facial asymmetry frequency in patients with head tilt, head turn, and orthotropic subjects was observed in 32 (97%), 50 (86.2%), and 22 (34.3%), respectively (P < 0.001). In patients with head tilt and head turn, the mean facial angle was 1.78º ± 1.01º and 1.19º ± 0.84º, respectively (P = 0.004) and the mean relative facial size was 1.027 ± 0.018 and 1.018 ± 0.014, respectively (P = 0.018). The frequencies of one-sided nostril compression, cheek compression, face compression, and columella deviation in patients with pure head tilt were found in 19 (58%), 21 (64%), 19 (58%), and 19 (58%) patients, respectively, and in patients with pure head turn the frequencies were observed in 42 (72%), 37 (63%), 27 (47%), and 43 (74%), respectively. All quantitative and qualitative facial asymmetry parameters and facial asymmetry frequencies were significantly higher in head tilt and head turn patients as compared to the control group (P < 0.001). Conclusion: All facial asymmetry parameters in patients with head tilt and head turn were significantly higher than orthotropic subjects. The quantitative parameters such as relative facial size and facial angle were significantly higher in patients with pure head tilt than pure head turn. The results revealed that pure head tilt was associated with a higher prevalence of facial asymmetry than pure head turn.

Comparative evaluation of spectral transmittance of some welding glasses with ANSI Z87.1

Background: Welding emits harmful rays to the eyes. We evaluate and compare the UV, blue light and IR transmittance characteristics of some currently available welding safety protectors with ANSI Z87.1 criteria

Materials and Methods: Three type of welding safety protectors [three of each type] have been evaluated for spectral transmittance. One-sample T-test was performed to establish is there a statistically significant difference between the standard criteria and UV, blue and IR regions for the welding protectors [alpha=0.05]

Results: In ultraviolet [UV] [far and near] region, two types of the tested protectors [P1, P2] transmitted lower than the maximum allowable value specified in the standard [P<0.001]. In infrared [IR] spectrum only one type [P3] transmitted lower than the maximum allowable value specified in the standard [P<0.001]. In blue light region, all of the tested protectors transmitted lower than the maximum allowable value specified in the standard [P<0.001]

Conclusion: Although all of the tested glasses could meet some parts of the criteria, but none of them could meet the complete spectral transmittance requirements of ANSI Z87.1

Effect of intra-canal direct current electric stimulation on orthodontic tooth movement: an experimental study in canines

Objectives: the purpose of this study was to evaluate whether intra-canal application of controlled direct electric current [DEC] could accelerate the amount of orthodontic tooth movement [OTM] in young adult mixed breed dogs

Methods: fourth premolars of both jaws of five young adult mixed breed dogs were divided into two groups of control and experimental groups. Orthodontic force was applied to both groups using an active NiTi push coil spring. Direct electric stimulation [15µA DC] was conducted by intra-canal usage of electric potential [1.5v]. The experimental teeth were compared with controls in terms of clinical OTM results measured with an electronic caliper every two weeks [four time intervals]. The animals were sacrificed one month [T2] or two months [T4] after initiation; and tissue sections were decalcified for histological evaluation. The data were analyzed using SPSS 16, Shapiro-Wilk test and paired t-test

Results: measurements revealed a statistically significant increase in OTM at electrically stimulated sites compared to the control sites in just one time interval [T3: after four weeks] [P< 0.05]. Histological sections also showed increased osteoblastic and osteoclastic activity at tension and compression sides of the experimental group compared to the control group, respectively at both time intervals [T2 and T4]

Conclusion: direct intra-canal electric current applied by a miniature electric device is effective for increasing the rate and amount of OTM in canine experimental model

Comparison of the effect of recaldent and xylitol on the amounts of salivary Streptococcus mutans

Dental caries is associated with oral pathogenes and Streptococcus mutans [S. mutans]is one of the primary cariogenic organisms. The aim of this clinical study was to evaluate the effect of sugar free chewing gum containing casein phosphopeptide-amorphous calcium phosphate [CPP-ACP] and Xylitol on salivary Streptococcus mutan. 60 dental students, who volunteered after signing an informed consent, were randomly allocated to receive one of the following interventions: [A] Chewing gum containing CPP-ACP, [B] Chewing gum containing Xylitol. Subjects within the experimental groups chewed gum for 20 minutes, three times a day after meals for 3 weeks. Pre- and post-intervention unstimulated saliva samples were quantified for Streptococcus mutans count. A statistically significant reduction [p<0.05] of salivary S. mutans was displayed in both groups A and B after the intervention. When results compared with baseline, and group A shows more statistically significant reduction of salivary S. mutans than group B. In conclusion, daily chewing gum containing CPP-ACP and xylitol reduce the level of salivary S. mutans in a significant way, but chewing gum containing CPP-ACP can reduce the level of salivary S. mutans in a significant way than Xylitol chewing gum

Review of Structural Social Determinants of Health in Early Childhood Development

Development is a dynamic and continuous phenomenon that is under the influence of various factors forming a complicated multidimensional system together. Any impairment in these factors can lead to impaired development in children, which is one of the most common problems in children. Therefore, this study provides a brief overview of these factors and the way they affect early childhood development. A brief review was performed in databases including Google scholar, PUBMED, Proquest, SID, Magiran, Iranmedex, Irandoc with following keywords: child development, income, occupation, education, employment, boy, girl, gender, sex, social class, Race and Ethnicity. All of article was reviewed then categorized based on WHO model. Among the papers reviewed, most of the studies were about employment, education, and income and most of them investigated these risk factors in terms of socioeconomic status. Structural factors of social determinants of health had a close relationship with each other, and they had affected development through each other. Given that, only few studies on structural factors, except for socioeconomic factors, have been conducted and little attention has been paid to the way these factors affect child development, further studies in this area are required to propose a model in order to better understand the interaction between these factors.

functional abilities and maximal vertical jumping height in coper and non-coper anterior cruciate ligament-deficient knee

The aim of the present study was to compare the performance of the vertical jump task and the level of disability between the coper and non-coper athletes with an anterior cruciate ligament-minus knee. Thirty-four professional male athletes with isolated complete anterior cruciate ligament -tear [age 20-29 years and 6-12 months time past injury] were recruited in this study. The subjects were allocated into the coper [n=17] and non-coper [n=17] groups according to their history of having giving way and feeling an instability in their injured knee. The maximum vertical jump height was recorded by a 6-camera Vicon motion analysis system. The functional outcomes of the subjects were assessed with use of the Persian versions of the International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score and Tegner Questionnaires. The results revealed that the coper ACK-deficient knee subjects had a significantly higher International Knee Documentation Committee score as well as two subscales of the KOOS questionnaire including the sports [p=0.001] and the quality of life [p=0.016] than non-copers. However, the subscales of pain [p=0.0137], symptoms [p=0.353] and the activities of daily living [p=0.133] of the KOOS questionnaire did not show any significant differences between the coper and non-coper ACL-deficient knee subjects. In addition, the maximum jumping height was significantly higher in the copers too [p=0.008]. While the pain, symptoms and daily activities were not different between the two groups, a higher level of the functional abilities, sports activities, quality of life and the maximum jumping height were shown in the coper ACL-deficient knee subjects when compared to the non-copers. A deliberate evaluation of the functional abilities in ACL-deficient knee subjects might play a key role in distinguishing the coper and non-coper ACL-deficient knee subjects

Zero inflated statistical count models for analysing the costs imposed by GERD and dyspepsia

Background and study aims: Recent studies have shown that the high prevalence and the various clinical presentations of gastro-oesophageal reflux disease [GERD] and dyspepsia impose an enormous economic burden on society. Economic cost data have unique characteristics: they are counts, and they have zero inflation. Therefore, these data require special models. Poisson regression [PR], negative binomial regression [NB], zero inflated Poisson [ZIP] and zero inflated negative binomial [ZINB] regression are the models used for analysing cost data in this paper

Patients and methods: In this study, a cross-sectional household survey was distributed to a random sample of individuals between May 2006 and December 2007 in the Tehran province of Iran to determine the prevalence of gastrointestinal symptoms and disorders and their related factors. The cost associated with each item was calculated. PR, NB, ZIP and ZINB models were used to analyse the data. The likelihood ratio test and the Voung test were used to conduct pairwise comparisons of the models. The log likelihood, the Akaike information criterion [AIC] and the Bayesian information criterion [BIC] were used to compare the performances of the models

Results: According to the likelihood ratio test and the Voung test and all three criteria used to compare the performance of the models, ZINB regression was identified as the best model for analysing the cost data. Sex, age, smoking status, BMI, insurance status and education were significant predictors

Conclusion: Because the NB model demonstrated a better fit than the PR and ZIP models, over-dispersion was clearly only due to unobserved heterogeneity. In contrast, according to the likelihood ratio test, the ZINB model was more appropriate than the ZIP model. The ZINB model for the cost data was more appropriate than the other models

Statistical count models for prognosis the risk factors of hepatitis C

The aim of this study was to compare alternatives methods for analysis of zero inflated count data and compare them with simple count models that are used by researchers frequently for such zero inflated data. Analysis of viral load and risk factors could predict likelihood of achieving sustain virological response [SVR]. This information is useful to protect a person from acquiring Hepatitis C virus [HCV] infection. The distribution of viral load contains a large proportion of excess zeros [HCV-RNA under 100], that can lead to over-dispersion. This data belonged to a longitudinal study conducted between 2005 and 2010. The response variable was the viral load of each HCV patient 6 months after the end of treatment. Poisson regression [PR], negative binomial regression [NB], zero inflated Poisson regression [ZIP] and zero inflated negative binomial regression [ZINB] models were carried out to the data respectively. Log likelihood, Akaike Information Criterion [AIC] and Bayesian Information Criterion [BIC] were used to compare performance of the models. According to all criterions, ZINB was the best model for analyzing this data. Age, having risk factors genotype 3 and protocol of treatment were being significant. Zero inflated negative binomial regression models fit the viral load data better than the Poisson, negative binomial and zero inflated Poisson models

[ effects of temperature and birth weight on the transition rate of hypothermia in hospitalized neonates using Markov models]

Hypothermia is an important determinant of survival in newborns, especially among low-birth-weight ones. Prolonged hypothermia leads to edema, generalized hemorrhage, jaundice and ultimately death. This study was undertaken to examine the factors affecting transition from hypothermic state in neonates. The study consisted of 439 neonates hospitalized in NICU of Valiasr in Tehran, Iran in 2005. The neonates' rectal temperature was measured immediately after birth and every 30 minutes afterwards, until neonates passed hypothermia stages. In order to estimate the rate of transition from neonatal hypothermic state, we used multistate Markov models with two covariates, birth weight and environmental temperature. We also used R package to fit the model. Estimated transition rates from severe hypothermia and mild hypothermia were 0.1192 and 0.0549 per minute, respectively. Weight had a significant effect on transition from hypothermia to normal condition [95% CI: 0.1364-0.4165, P<0.001]. Environmental temperature significantly affected the transition from hypothermia to normal stage [95% CI: 0.0439-0.4963, P<0.001]. The results of this study showed that neonates with normal weight and neonates in an environmental temperature greater than 28°C had a higher transition rate from hypothermia stages. Since birth weight at the time of delivery is not under the control of medical staff, keeping the environmental temperature in an optimum level could help neonates to pass through the hypothermia stages faster

[Challenges of change management: a qualitative study on managers' experiences in nursing and midwifery schools]

The objective of this study was to investigate perspectives of managers regarding change management in nursing and midwifery schools. In this qualitative study, we used a descriptive exploratory approach with triangulation. We used snow ball sampling to recruit faculty members of nursing and midwifery schools in Tehran. The participants were included in the study if they had at least 1-year experience as a faculty member. Data were gathered using semi-structured interviews in which a guide and field notes were used. Data were saturated after observing repetition of the codes. Latent content analysis was used for data analysis. The trustworthiness was achieved using a prolonged field experience, member check, peer check and sharing the content with two qualitative research experts. Ten participants [seven females and three males] aged 38-54 were interviewed. Three participants were employed in highly recognized management levels. Immediately after interviews, conceptual codes were extracted. Suggested themes were classified as concentration in management, managers' characteristics, and attitude toward change. Accordingly, the concept of change management was postulated as the purpose of this study. Furthermore, its influencing factors were identified. The results of this study can be used by faculties of the nursing and midwifery schools to use them according to their organizational culture

Comparison of neutrophil apoptosis alpha-defensins and calprotectin in children with and without severe early childhood caries

The infectious nature of severe early-childhood caries[S-ECC] points to the possible participation of immunologic host responses including neutrophils and their antimicrobial products. The aim of this study was to determine the neutrophil apoptosis, alpha-defensins [HNP1-3] and calprotectin levels in the saliva of preschool children and the association with S-ECC. Oral examinations were performed on 87 children aged 3-5 years and non stimulated whole saliva samples were collected. Thirty of these subjects were considered S-ECC children, 30 with moderate caries [MC] and 27 were caries free [CF]. to detect apoptosis, cell staining was done with Annexin-V-Fluos and propidium iodide, and they were analyzed by fluorescent microscopy. The concentration of alpha-defensins and calprotectin were assessed using ELISA. There were no statistical differences between groups considering the HNP1-3 or calprotectin salivary levels[p=0.06 and p=0.23, respectively]. The HNP1-3 and calprotectin levels were negatively correlated and the correlation was significant in MC group [p=0.03]. Lower levels of apoptotic neutrophils were obtained from CF subjects as compared with S-ECC children [p=0.03]. Our findings establish that apoptotic mechanisms could be implicated in the immunity responses associated with S-ECC. We cannot yet determine if the level of salivary alpha-defensins or calprotectin is predictive of S-ECC

Periapical status and quality of root canal fillings and coronal restorations in Iranian population

This cross-sectional survey determined the dental prevalence of apical periodontitis [AP] in selected Iranian population, and evaluated the influence of the quality of root canal treatment [RCT] and their coronal restorations [CR] on the periapical status. A total of 1064 panoramic radiographies were evaluated by two observers during 2009. The quality of RCT i.e. length/density of root fillings and CR in addition to periapical status of endodontically treated teeth were recorded. Their interrelationship was analyzed by Chi-squared, logistic regression and Spearman's rho statistics. Hosmer and Lemeshow tests were used for assessing fitness of logistic regression model and one sample k-s test was used for evaluating of normality of the data. Our results showed that 527 teeth [52%] of the endodontically treated teeth presented with AP radiographically. The percentages of teeth which fulfilled the criteria of an acceptable RCT or CR radiographically were 42.3 and 62.5 respectively. Incidence of AP among teeth with acceptable RCT [29.1%] was significantly lower than those suffering from unacceptable RCT [68.8%] [P<0.001]. Moreover, adequate CR demonstrated a significantly better periapical status [58.6%] compared to teeth with inadequate CR [30.3%] [P<0.001]. The incidence of AP ranged from 25.6% [good qualities] to 79.5% [bad qualities] [P<0.001]. Cases with both unacceptable RCT/CR were 11 times more likely to have AP than cases with acceptable RCT/CR. The quality of RCT and CR were found to impact the periapical health of endodontically treated teeth. There are a significant high number of technically unacceptable endodontic and restorative treatments in Iran; therefore considerable efforts are needed to improve the standards of endodontic and restorative treatments

Comparison between the precision of measurements in two types of the micropipettes according to CLSI EPS and ISO 8655

In the diagnosis medical labs, it is very important to evaluate the precision of micropipettes in transferring small amounts of liquids. The medical tests will not result accurately, if the liquid volume doesn't transfer exactly by micropipettes. Thus the doctor faces sort of problems in the disease diagnosis and its control. In the standard CLSI EPS, there is a method to specify and assess the precision of micropipettes, by using CV [coefficients of variation]. Also there are other methods to estimate and test the mention CV theory, in the formal statistic texts which could be used to assess the micropipettes precision. It is the main goal of this research to study the precision of lab micropipettes which are shown by A and B and compared by reference standard value from ISO 8655. In this research we evaluate the precision of the lab micropipettes. Two brands A and B are assigned to measure the distilled water mass by using the accurate scale which is accurate up to 10-6 to measure 50 gram weight. The experimental eenvironment is a metrology lab which is confirmed by Iran Standard and Industrial Researches. A unique technician sampled in the beginning of the work time and after 2 hours repeated the sampling. Totally, each micropipette is used to measure 40 times with 10 times repeat for single measurement in 28 work days. It is used common statistical methods to estimate and test the coefficients of variation theory. Point estimation of CV for micropipettes A and B were 0.50% and 0.64% respectively. Also the 95% confidence upper bounds for these two micropipettes by using likelihood ratio method were 0.53% and 0.64% respectively. The micropipette A confirmed the ISO 8655, but the micropipette B did not. Measurement error in micropipette B was 30% less than micropipette A in average. By using the approach of CLS EP5 and confidence interval for CV, precision of two micropipettes were compared. Only one of them confirmed the ISO 8655, but the other one was failed

Comparing alveolar bone regeneration using Bio-Oss and autogenous bone grafts in humans: a systematic review and meta-analysis

Bone regeneration grafts [BRG] are widely used in the treatment of osseous defects and oral surgery. The various techniques and associated success rates of bone augmentation require evaluation by systematic review and meta-analysis of eligible studies. The aim of this systematic review was to compare alveolar bone regeneration in humans using Bio-Oss and autogenous bone graft. The computerized bibliographical databases including Pubmed, Google, ScienceDirect and Cochrane were searched for randomized and cohort studies in which autogenous grafts were compared to Bio-Oss in the treatment of periodontal defects. The inclusion criteria were human studies in English that were published 1998-2009. Exclusion criteria included non randomized observation and cohort studies, papers which provided summary statistics without the variance estimates, and studies that did not use BRG intervention alone, were excluded. The screening of eligible studies, assessment of the methodological quality of the trials and data extraction were collected by two observers independently. For comparing autogenous grafts used alone against Bio-Oss used alone 5 situations were investigated. Thirteen studies were included in the review which compared autogenous against Bio-Oss, autogenous combined with guided tissue regeneration [GTR] against GTR, Bio-Oss combined with GTR versus GTR, autogenous alone versus Open Flap Debridement [OFD], Bio-Oss versus OFD. In meta-analysis, changes in bone level [bone fill] was used as the measure. Data were analyzed using Bayesian meta-analysis by WinBUGS and Boa software. Only one comparison demonstrated that the difference in bone augmentation between Bio-Oss and OFD was statistically significant. There is insufficient evidence to show that Bio-Oss is superior to autogenous grafts in bone augmentation techniques however autogenous bone involves donor site surgery and thus donor site morbidity, so we can conclude that Bio-Oss is better than autogenous for alveolar regeneration

Particle size of a new endodontic cement compared to root MTA and calcium hydroxide

Particle size and distribution can influence the properties of materials. This study analyzed and compared the particle size of Root MTA, calcium hydroxide [CH], and a new endodontic cement called calcium enriched material [CEM]. The particle size of each material was analyzed three times using 0.05 mg of test material with a particle size analyzer. The particle size distribution ranges, the cumulative percentage and the mean of particle sizes were calculated. One-way ANOVA, Tukey, and Chi-square tests were used for statistical analyses. Results demonstrated that the distribution of particles was dissimilar. Particle mean size in the three different materials was not significantly different. However, the cumulative percentage of CH and CEM cement particles size demonstrated significant difference [P<0.05]. Among the various particle size distributions, the particle distribution in the size range of

[Assessing validity of dentists evaluations in measuring Index of Orthodontic Treatment Need using modeling agreement]

In assessment orthodontic treatment need, for the same group of people, dentists usually have different ideas with respect to a gold standard. The most common way of determining validity of the assessments is computing coefficients of agreement like Kappa and Weighted Kappa. In this article we first present shortcomings of the coefficients and then propose a more appropriate alternative method for evaluating of agreement. This analytic cross-sectional investigation has been done with the Index of Orthodontic Treatment Need [IOTN]. This index which independently was measured on 51 study models by an expert dentist [as gold standard] and 10 other dentists [as raters], has 5 ordinal levels [no need, little/mild need, moderate/borderline need, severe need, extreme need]. Diagonal parameter model and uniform association model were used for modeling agreement to evaluate validity of the assessments. In 6 cases, diagonal parameter model [with significance level at least 0.34] and in 4 other cases, uniform association model [with significance level at least 0.36] were appropriate to the relevant data. The best assessments belong to the dentists for whom uniform association model was fitted and the worst of them to the dentists for whom diagonal parameter model was fitted. All of the dentists tended to rate casts higher than the gold standard, so that local odds ratio for dentist who had the least[most] tendency to rate casts higher than the gold standard was 6.4[121.5], So all of them needed to be further educated to assess the index