Surface electromyography pattern of human swallowing

<p>Abstract</p> <p>Background</p> <p>The physiology of swallowing is characterized by a complex and coordinated activation of many stomatognathic, pharyngeal, and laryngeal muscles. Kinetics and electromyographic studies have widely investigated the pharyngeal and laryngeal pattern of deglutition in order to point out the differences between normal and dysphagic people. In the dental field, muscular activation during swallowing is believed to be the cause of malocclusion.</p> <p>Despite the clinical importance given to spontaneous swallowing, few physiologic works have studied stomatognathic muscular activation and mandibular movement during spontaneous saliva swallowing.</p> <p>The aim of our study was to investigate the activity patterns of the mandibular elevator muscles (masseter and anterior temporalis muscles), the submental muscles, and the neck muscles (sternocleidomastoid muscles) in healthy people during spontaneous swallowing of saliva and to relate the muscular activities to mandibular movement.</p> <p>Methods</p> <p>The spontaneous swallowing of saliva of 111 healthy individuals was analyzed using surface electromyography (SEMG) and a computerized kinesiography of mandibular movement.</p> <p>Results</p> <p>Fifty-seven of 111 patients swallowed without occlusal contact (SNOC) and 54 individuals had occlusal contact (SOC). The sternocleidomastoid muscles showed a slight, but constant activation during swallowing. The SEMG of the submental and sternocleidomastoid muscles showed no differences between the two groups. The SEMG of the anterior temporalis and masseter muscles showed significant differences (p < 0.0001). The duration of swallowing was significantly higher in the SNOC subjects. Gender and age were not related to electromyographic activation. Healthy SOC and SNOC behaved in different ways.</p> <p>Conclusion</p> <p>The data suggest that there is not a single "normal" or "typical" pattern for spontaneous saliva swallowing. The polygraph seemed a valuable, simple, non-invasive and reliable tool to study the physiology of swallowing.</p

QT Interval Prolongation and Torsade De Pointes in Patients with COVID-19 treated with Hydroxychloroquine/Azithromycin

Background: There is no known effective therapy for patients with COVID-19. Initial reports suggesting the potential benefit of Hydroxychloroquine/Azithromycin (HY/AZ) have resulted in massive adoption of this combination worldwide. However, while the true efficacy of this regimen is unknown, initial reports have raised concerns regarding the potential risk of QT prolongation and induction of torsade de pointes (TdP). Objective: to assess the change in QTc interval and arrhythmic events in patients with COVID-19 treated with HY/AZ METHODS: This is a retrospective study of 251 patients from two centers, diagnosed with COVID-19 and treated with HY/AZ. We reviewed ECG tracings from baseline and until 3 days after completion of therapy to determine the progression of QTc and incidence of arrhythmia and mortality. Results: QTc prolonged in parallel with increasing drug exposure and incompletely shortened after its completion. Extreme new QTc prolongation to &gt; 500 ms, a known marker of high risk for TdP had developed in 23% of patients. One patient developed polymorphic ventricular tachycardia (VT) suspected as TdP, requiring emergent cardioversion. Seven patients required premature termination of therapy. The baseline QTc of patients exhibiting extreme QTc prolongation was normal. Conclusion: The combination of HY/AZ significantly prolongs the QTc in patients with COVID-19. This prolongation may be responsible for life threating arrhythmia in the form of TdP. This risk mandates careful consideration of HY/AZ therapy in lights of its unproven efficacy. Strict QTc monitoring should be performed if the regimen is given

Reverse cycle chewing before and after orthodontic-surgical correction in class III patients

Objective: The aim of this study was to investigate the prevalence of reverse-sequence chewing cycles in skeletal class III patients before and after orthodontic-surgical therapy to evaluate whether the occlusal and skeletal correction is followed by a functional improvement. Study Design: Twenty skeletal class III patients (11 males and 9 females, 22.7 ± 3.0 years old) were recruited for this study. All patients received orthodontic and surgical treatment. Chewing cycles were recorded with a kinesiograph before (T0) and after (T1) therapy. Results: A significant decrease in the number of reverse chewing cycles after surgical correction was exhibited in all recordings, when chewing either soft or hard boluses, on both the right and the left side. Conclusions: Evaluation of the prevalence of reverse chewing cycles could be considered an indicator of functional adaptation after therapy and a method for the early detection of nonresponding patients who may require further consideration using a different approach

Standard of disocclusion in complete dentures supported by implants without free distal ends: analysis by the finite elements method

OBJECTIVE: The occlusal patterns are key requirements for the clinical success of oral rehabilitation supported by implants. This study compared the stresses generated by the disocclusion in the canine guide occlusion (CGO) and bilateral balanced occlusion (BBO) on the implants and metallic infrastructure of a complete Brånemark protocol-type denture modified with the inclusion of one posterior short implant on each side. MATERIAL AND METHODS: A three-dimensional model simulated a mandible with seven titanium implants as pillars, five of them installed between the mental foramen and the two posterior implants, located at the midpoint of the occlusal surface of the first molar. A load of 15 N with an angle of 45º was applied to a tooth or distributed across three teeth to simulate the CGO or BBO, respectively. The commercial program ABAQUS(®) was used for the model development, before and after the processing of the data. The results were based on a linear static analysis and were used to compare the magnitude of the equivalent stress for each of the simulations. RESULTS: The results showed that the disocclusion in CGO generated higher stresses concentrated on the working side in the region of the short implant. In BBO, the stresses were less intense and more evenly distributed on the prosthesis. The maximum stress found in the simulation of the disocclusion in CGO was two times higher than that found in the simulation of the BBO. The point of maximum stress was located in the neck of the short implant on the working side. CONCLUSIONS: Under the conditions of this study, it was concluded that the BBO pattern was more suitable than CGO for the lower complete denture supported by implants without free distal ends

BMQ

BMQ: Boston Medical Quarterly was published from 1950-1966 by the Boston University School of Medicine and the Massachusetts Memorial Hospitals

An engagement with the phenomenology of leadership

The quantity of emerging literature on the subject of leadership testifies to the urgency that is felt in these times for understanding it. The phenomenon of leadership is a subtle one and each author is at pains to justify their particular slant on its nature. This thesis shifts away from trying to find essential qualities of leadership that are generically applicable and instead considers leadership as it is experienced. It therefore examines leadership as a personal phenomenon regardless of the position held. The phenomenon is recognised through the experience of those who are present to its influence. This includes the practitioner, in any role or job, for whom the experience of leadership is necessarily personal and its expression evolving rather than static. I have chosen the method of conversation to identify the presence of such a phenomenon. This provides an expansive format which, because it is a lived experience, provides access to people’s experience of leadership, both their own and that of others’. I have used reflexive and imaginative writing processes to express and develop theory and praxis. Through these means, I have examined leadership as an engagement and used myself as a presence in order to develop insight. The thesis draws on the philosophical tradition of Goethe, Husserl, Bohm and Varela to understand the nature of experience and change; qualitative researchers like Van Manen, Crotty and Reason to develop reflective tools of inquiring; and leadership thinkers such as Senge, Jaworski, Scharmer and Mintzberg to find more vital ways of considering the very human experience of leadership in these times of rapid change. The thesis showcases an evaluation of leadership in a medium-sized industrial organisation in Western Australia. The task of the study was to assess the change in leadership in the whole organisation as a result of management attending a leadership program. For this purpose, phenomenological research methods were used to provide an in-depth and experientially based methodology. Narrative analysis offered the ground for capturing the presence of leadership through expressing the whole spectrum of voices in the organisation. Further, first-person methods brought relational sensitivity and researcher engagement, immersion and leadership. The evaluation resulted in a confronting report that enabled new ways of hearing between management and non-management and the organisation was enabled to take its next steps forward consensually. The study is followed by three exploratory chapters that deal with: How does the ‘new’ get dreamed up? What are the big issues of leadership that challenge the establishment? What does change actually imply and why is this so important to leadership? I protest the flippancy with which organisational consultants and leaders confuse structural change with the change that people really desire. The crystallisation of my exploration into the phenomenon of leadership transpires through a synchronous event. This was a personal experience of leadership. I apply a classical philosophical phenomenological analysis to my story as a narrative. This results in a new theoretical framework which I have called confluential leadership: the interaction of the constellations of synchronicity, clarity of intention and co-creativeness. The appreciation of these influences within one����s role is a meaning-making or enhancing process. This can result in greater engagement with one’s role or perhaps the realisation that one is in the wrong job! The centrality of my own engagement, a feature of the research conducted through this thesis, has resulted in the development of a passion for the subject of leadership and an enthusiasm for the possibilities of advancing and applying many of the ideas introduced. I have found that in order to find leadership, one has to bring leadership and the quality of that intention determines what one finds. Similarly, when leadership is experienced in a workplace, others are influenced to present the best of their own leadership. There is always the possibility for each person to enhance their own experience of leadership to become more integrated, wholesome and passionate about their work. The potentiality of this excites me. Confluential is my own word and is a combination of the words consciousness and influence. It is the conscious influence of the three constellations of synchronicity, clarity of intention and co-creativeness. Each of these has been very specifically defined; their meanings are carefully discussed in the body of the thesis