A Cross-Sectional Study of Temporomandibular Disorders Among Postgraduate Students.

PURPOSE: The aim of this study is to investigate the prevalence of (TMD) as well as their potential risk factors among postgraduate students. MATERIALS AND METHODS: In this cross-sectional and correlation study, 1255 postgraduate students from different universities were recruited to answer Fonseca's anamnestic index (FAI) in addition to collected demographic data and relevant dental history. Fonseca's anamnestic index (FAI) was used to classify their TMD severity. Five hundred ninety-three participants, that had previous clinical/radiographic TMD reports, out of 1255 were included. Chi-square and fisher's exact tests investigated the relation between each predictor and TMD at P≤.05. A logistic binary regression analysis examined the model fit using -2Log likelihood and Pseudo R2 tests at P≤.05. RESULTS: Based on previous clinical/radiographic reports and on FAI, 73.4% of the participants had TMD, of which 57% had mild dysfunction, followed by moderate (31.7%), and severe (11.3%). There was a statistically significant association between sex, depression, lip/object biting and clenching with TMD (P <.001), where females were 2.302 times more likely to develop TMD than males. The combination of lip biting and clenching in a female dramatically increases the risk of TMD (-2 Log Likelihood =385.7, P<.001 and a Cox and Snell value = 0.315 and a Nagelkerke value = 0.395). CONCLUSION: TMD seems to be highly prevalent among postgraduate students in Egypt, whereby female postgraduate students who bite their lips and/or grind their teeth are particularly highly prone to the condition. Object biting and depression could be also considered as risk factors.

Marmoset brain segmentation from deconvolved magnetic resonance images and estimated label maps.

PURPOSE: The proposed method aims to create label maps that can be used for the segmentation of animal brain MR images without the need of a brain template. This is achieved by performing a joint deconvolution and segmentation of the brain MR images. METHODS: It is based on modeling locally the image statistics using a generalized Gaussian distribution (GGD) and couples the deconvolved image and its corresponding labels map using the GGD-Potts model. Because of the complexity of the resulting Bayesian estimators of the unknown model parameters, a Gibbs sampler is used to generate samples following the desired posterior probability. RESULTS: The performance of the proposed algorithm is assessed on simulated and real MR images by the segmentation of enhanced marmoset brain images into its main compartments using the corresponding label maps created. Quantitative assessment showed that this method presents results that are comparable to those obtained with the classical method-registering the volumes to a brain template. CONCLUSION: The proposed method of using labels as prior information for brain segmentation provides a similar or a slightly better performance compared with the classical reference method based on a dedicated template.

Performance comparison of coupling-evaluation methods in discriminating between pregnancy and labor EHG signals.

BACKGROUND: Recent years have seen an increased interest in electrohysterogram (EHG) signals as a means to evaluate the synchronization of uterine contractions. Several studies have pointed out that the quality of signal processing - and hence the interpretation of measurement results - is affected significantly by the choice of measurement technique and the presence of non-stationary frequency content in EHG signals. To our knowledge, the effect of time variance on the quality of EHG signal processing has never been fully investigated. How best to process EHG signals with the goal of distinguishing labor-induced contractions from their harmless, pre-labor cousins, remains an open question. METHOD: Our methodology is based on three pillars. The first consists of a new method for EHG preprocessing in which we apply a second-order Butterworth filter to retain only the EHG fast-wave, low-frequency band (FWL), then use a bivariate piecewise stationary pre-segmentation (bPSP) algorithm to segment the EHG signal into stationary parts. The second pillar addresses the estimation of connectivity and directionality using three methods: nonlinear correlation coefficient (h2), general synchronization (H), and Granger causality (GC). The third pillar is related to signal classification and discrimination between pregnancy and labor using receiver operating curves (ROC) and connectivity and direction maps. For this purpose, we analyze the impact of four factors on data processing efficiency: i) method of connectivity detection, ii) effect of piecewise stationary segmentation preprocessing, iii) retained frequency content and iv) electrode configuration used for EHG recording (bipolar vs. unipolar). RESULTS: Our results show that piecewise signal segmentation and filtering considerably improves classification performance and statistical significance for some connectivity methods, in particular the h2. To this end we propose a new approach (detailed below) for h2 called Filtered-Windowed (FW) h2 that better highlights the differences between pregnancy and labor in the connectivity matrix and directionality maps. CONCLUSIONS: This is the first comparative study of the effects of multiple processing factors on connectivity measurement efficiency. Our results indicate that appropriate preprocessing can improve the differentiation of pregnancy and labor-induced contraction signals and may lead to innovative applications in the prevention of preterm labor.

Effect of Mental Calculation and Number Comparison on a Manual-Pointing Movement.

The present study aimed at examining the effect of mental calculation and number comparison on motor performance measured as the movement time of a fast manual-pointing movement. Three experiments, involving a total number of 65 undergraduate subjects, examined the effect of mental subtraction (complex) and, respectively, of (a) mental addition (simple or complex), (b) mental multiplication (simple or complex), and (c) the comparison of dot sets and number comparison. Each number was written in Arabic. The movement times were analyzed by using a multilevel linear mixed-effect model. The results showed significant improvement of manual-pointing movement performance only after the complex calculations and after number comparison. Possible implication of attentional mechanisms specific to this arithmetical activity is further discussed.

The equatorial rainforest of Central Africa between economic needs and sustainability requirements.

This article sets out to investigate the role played by the rainforest of Central Africa in providing environmental goods and services, regulating and stabilizing the global climate as well as participating in socio-economic development of the riparian countries. This complex role offers a double status, almost confrontational, to this rainforest: it stands as an economic resource and as a major global climate regulator. Hence, there is an urgent need to question certain aspects such as climate trends in this strategic region and the use of local forest resources for economic purpose in order to suggest ecological attitudes to be adopted by policymakers, stakeholders, forest professionals and users for a sustainable development. It is shown that: 1) this rainforest constitutes an economic resource and plays a major socio-cultural role in addition to its global climate regulatory role, 2) an overexploitation of the forest resources for economic purposes exposes the forest to an increased deterioration which can change the ecological and socio-economic balance, or destroy this forest, and by so doing, alter its global climate control power, 3) the climate of the region is experiencing serious variability. Thus, solutions that can satisfy socio-economic needs and give room for sustainable development are proposed.

Variation-based sparse source imaging in localizing uterine activity.

Electrohysterogram source imaging, i.e., moving from the electrode/sensor space to the source space using EHG signals, provide an estimate of spatial distributions of uterine activity at millisecond scale. This paper aims to study the ability of different distributed source localization methods to recover uterine electrical activity sources. Performance was quantified using a detection accuracy index. Our result suggests that the variation based method is able to reconstruct extended uterus sources with the overall high accuracy, where the increasing of the electrodes numbers and the decreasing of the fat thickness induce a better accuracy in localization.

Effect of filtering on the classification rate of nonlinear analysis methods applied to uterine EMG signals.

Nonlinear time series analysis can provide useful information regarding nonlinear features of biological signals. The effect of filtering on the performance of nonlinear methods is not well-understood. In this work, we investigate the effects of signal filtering on the sensitivity of four nonlinear methods: Time reversibility, Sample Entropy, Lyapunov Exponents and Delay Vector Variance. These methods were applied to uterine EMG signals with the aim of using them to discriminate between pregnancy and labor contractions. The signals were filtered using three different band-pass filters before the application of the methods. Results showed that the sensitivity of some methods such as sample entropy was significantly improved with filtering. On the other hand, filtering had little effect on some other methods such as time reversibility. This study concludes that while filtering increases computation time, it may be necessary for some nonlinear methods particularly those with low sensitivity.

Performance analysis of four nonlinearity analysis methods using a model with variable complexity and application to uterine EMG signals.

Several measures have been proposed to detect nonlinear characteristics in time series. Results on time series, multiple surrogates and their z-score are used to statistically test for the presence or absence of non-linearity. The z-score itself has sometimes been used as a measure of nonlinearity. The sensitivity of nonlinear methods to the nonlinearity level and their robustness to noise have rarely been evaluated in the past. While surrogates are important tools to rigorously detect nonlinearity, their usefulness for evaluating the level of nonlinearity is not clear. In this paper we investigate the performance of four methods arising from three families that are widely used in non-linearity detection: statistics (time reversibility), predictability (sample entropy, delay vector variance) and chaos theory (Lyapunov exponents). We used sensitivity to increasing complexity and the mean square error (MSE) of Monte Carlo instances for quantitative comparison of their performances. These methods were applied to a Henon nonlinear synthetic model in which we can vary the complexity degree (CD). This was done first by applying the methods directly to the signal and then using the z-score (surrogates) with and without added noise. The methods were then applied to real uterine EMG signals and used to distinguish between pregnancy and labor contraction bursts. The discrimination performances were compared to linear frequency based methods classically used for the same purpose such as mean power frequency (MPF), peak frequency (PF) and median frequency (MF). The results show noticeable difference between different methods, with a clear superiority of some of the nonlinear methods (time reversibility, Lyapunov exponents) over the linear methods. Applying the methods directly to the signals gave better results than using the z-score, except for sample entropy.

Schwannoma of the nasal tip: diagnosis and treatment.

BACKGROUND: Schwannoma is a neurogenic neoplasm rarely found in the sinonasal tract. It is a benign tumor arising from the sheath of myelinated nerve fibers that may occur in any part of the body. Its diagnosis and treatment can pose certain challenges. METHODS: A 35-year-old woman presented to the senior surgeon with a nasal tip tumor that had been developing for almost 10 years. Ultrasound showed edema of the nose because of multiple solid nodes. The computed tomography (CT) scan did not show invasion of the bony framework around the tumor (maxilla, septum, nasal bones). Magnetic resonance imaging (MRI) showed a deviation of the septum and well-defined round nodes at the nasal tip with a thick layer of skin around them. Resection of the tumor was performed using open rhinoplasty. RESULTS: The limits of the excision were free of tumor, and histologic analysis of the tumor showed the characteristics of a schwannoma. At this writing, 2 years postoperatively, the patient is free of recurrence. CONCLUSION: Schwannoma of the nasal tip is a benign tumor that gradually causes aesthetic and functional disorders. Radiologic examinations can assist in its diagnosis. The treatment is surgical excision and histologic analysis of the specimen.

Short bowel syndrome: amelioration of diarrhea after vagotomy and pyloroplasty for peptic hemorrhage.

Acute mesenteric ischemia is a rare symptomatic manifestation of arteriosclerosis. Prognosis crucially depends on rapid diagnosis and surgical management to prevent or at least minimize the bowel infarction. The length of the small bowel is considered to be between 3 and 8 m, and a normal bowel function can be maintained even after resection of its one third. But loss of a major part (> 60%) can lead to malnutrition and death. However, patients, who survived an extended intestinal resection due to improved postoperative care (intensive care unit and parenteral nutrition), develop short bowel syndrome. This phenomenon is a medical problem, and several surgical techniques have been used to slow down intestinal transit time or to increase the area of absorption. All these procedures have controversial outcomes and are still on different experimental levels; namely, they cannot be recommended for routine use. In our report of a patient suffering from short bowel syndrome, vagotomy and pyloroplasty were performed to repair a sudden peptic hemorrhage. This operation cured bleeding peptic ulcer and also palliated the diarrhea, a main clinical manifestation of short bowel syndrome. In this study, our aim is to emphasize the favorable clinical outcome of vagotomy concerning a principal manifestation of short bowel syndrome, such as diarrhea. To the best of our knowledge, the present study is the first report showing the vagotomy as a possible procedure for the treatment of diarrhea, although this occurrence has no clear explanation. We also discuss the management of short bowel syndrome.

Wandering spleen with torsion of the pedicle.

Wandering spleen is a rare medical entity. It usually occurs at 20-40 years of age, and most cases are seen in women. Clinical diagnosis is difficult due to lack of symptoms, unless splenic torsion has occurred and clinical symptomatology of acute abdomen develops. The diagnosis can be confirmed by imaging techniques. Treatment is operative due to complications of splenic infarction. Splenopexy is the usual treatment, except for cases of splenic infarction. Splenectomy should be carried out when there is no evidence of splenic blood flow after detorsion of the spleen and in cases of excessive splenomegaly.

The use of oxygen in Fournier's gangrene.

Fournier's gangrene is an aggressive form of necrotizing fasciitis of the perineal, perianal or genital regions, usually caused by a polymicrobial infection that includes virulent organisms. Over the last decades, we have treated 9 patients suffering from Fournier's gangrene using systemic chemotherapy with broad-spectrum antibiotics, and with extensive, sometimes serial surgical debridement. Recently in one case, in addition to treatment, we used locally 100% oxygen in daily doses with promising results in healing wound. Herein, we report this case with a brief review of the literature concerning pathogenesis, risk factors, and treatment approaches.

Co-existence of spontaneous splenic rupture and tuberculosis of the spleen.

A rare case of splenic tuberculosis complicated by splenic rupture is reported. A 73-year-old man, hospitalized for peptic ulcer bleeding, presented in oligemic shock, was transferred to the operating room. Hemoperitoneum, due to rupture of an enlarged spleen was detected. The pathology revealed splenic tuberculosis. He had an uneventful recovery. Postoperatively, he received a combination of anti-tuberculous therapy for 6 months.

Granuloma of the appendiceal stump. An unusual cause of right hemicolectomy.

Granuloma of the appendiceal stump is not a common surgical entity. However, hemorrhage which may lead to right hemicolectomy is rare in fact. We report this case, in order to avoid this kind of overtherapy.