The Prevalence and Overlaps of Temporomandibular Disorders in Patients with Myofascial Pain with Referral—A Pilot Study

The aim of the study was to evaluate the temporomandibular joint, the prevalence of single and multiple diagnosis and potential sided domination of temporomandibular dysfunction in patients with temporomandibular disorder—myofascial pain with referral. The study group enrolled 50 people—37 females and 13 males between 18 and 25 years old with an average age of 23.36 ± 2.14. The patients underwent joint vibration analysis. Sixty seven percent of all examined tem-poromandibular joints were classified as group I according to Mark Piper’s classification. Class IIIA appeared in 17% of joints. Eight percent of temporomandibular joints were classified as class IVA. There were no statistically significant differences in the prevalence of temporomandibular disorder with respect to gender (p = 0.838639). The relatively high prevalence of multiple diagnoses proved the overlapping nature of muscle and intraarticular disorders. Twenty eight percent of the subjects suffered from a combination of myofascial pain with referral and bilateral temporoman-dibular dysfunction. In 62% of the patients a lack of intraarticular disorders was reported. The suggestion that there exists sided domination in the occurrence of temporomandibular disorders has not been confirmed. Due to the small sample size, such differences cannot be excluded. Fur-ther research is needed.

Модификация инерционно-жесткостных характеристик модели как путь решения задач о ее установившихся колебаниях

В статье предлагается метод, реализация которого позволит единообразно решать задачи об установившихся колебаниях конструкций, моделируемых квазиодномерными моделями. Суть метода состоит в коррекции и модификации значений инерционно-жесткостных характеристик такой модели, а так же внешней нагрузки, на нее действующей. При реализации метода учет влияния дополнительных факторов, усложняющих картину вибрации, осуществляется автоматически. В качестве примера рассмотрена задача о совместной вибрации судового корпуса и его конструктивного модуля в случае сравнительно небольшой протяженности района их сопряжения. Проанализированы первые варианты решения авторами задачи. Для плоского варианта задачи о совместной вибрации судового корпуса и конструктивного модуля выполнен анализ дополнительной нагрузки. Сформирована обобщенная матрица инерции конечного элемента модели судового корпуса в точке сопряжения. Приведена обобщенная матрица инерции для случая присоединения модуля L-образной формы. Предложен алгоритм расчета параметров вибрации (на основе дискретного варианта метода парциальных откликов). Выведены формулы для парциальных откликов и парциальных параметров, необходимые при реализации предложенного алгоритма.The article proposes a method, the implementation of which will uniformly solve the problem of steady-state oscillations of сотstructures modeled by quasi-one-dimensional models. The method consists in correcting and modification the values of the previous inertial-stiffness characteristics of such a model, as well as the external load acting on it.. When implementing the method, the influence of additional factors complicating the picture of vibration is taken into account automatically. The problem of joint vibration of the ships hull and its structural module in the case of a relatively small length of the area of their contact is considered. The authors analyzed the first variants of solution of the problem. For the two-dimensional version of the problem of joint vibration of the ships hull and structural module, the analysis of the additional load is performed. A generalized inertia matrix of the finite element of the ship hull model at the contact point with the L- element is formed. The algorithm of calculation of parameters of a vibration (on the basis of a discrete variant of a method of partial responses) is offered. Formulas for partial responses and partial parameters necessary for the implementation of the proposed algorithm were created.

Research on a Multinode Joint Vibration Control Strategy for Controlling the Steering Wheel of a Commercial Vehicle

The vibration degree of a steering wheel has important reference significance for drivers to evaluate the ride comfort of the whole vehicle. To solve the jitter problem of the steering wheel of a commercial vehicle at idle speed, this work proposes a multinode joint vibration control strategy (MDVC) based on the associated vibration path of the steering wheel. Based on the analysis of the associated vibration transfer paths of the steering wheel, the whole vehicle was divided into a system comprising several nodes. For the decomposed node system, taking the vibration transmission path associated with the target as the research direction, the vibration reduction design of each node system is analyzed step by step. After exploring the possible causes of abnormal vibration of the steering wheel through experimental tests, the abnormal node structure interval was determined. By further extracting the structural model of the steering system from the vehicle, the hammering method was applied to test its modal and related frequency. Furthermore, an improved structure of steering support was also designed, and its fitting degree and modal characteristics were analyzed and compared to the original scheme. The following test results show that the structure improvement greatly reduces the vibration level of the steering wheel, meets the ideal design requirements of the steering wheel vibration reduction, and provides the possibility of weighing the correlation between these hierarchical node systems in whole vehicle.

Joint Vibration Analysis (JVA) and the Diagnostic Process in TMD

This chapter describes joint vibration analysis technology (JVA), that assesses pathological changes that can occur within the temporomandibular joints. The diagnostic process and a simplified approach to better understand and efficiently treat temporomandibular dysfunction (TMD), will be overviewed. With over 38 different etiologies under the umbrella term “TMD,” the need to streamline and effectively determine an accurate definitive diagnosis and potential treatment options becomes apparent. Joint vibration analysis (JVA) uses tissue accelerometers to objectively capture vibrations given off by structurally compromised, internal TM joint anatomy. This structural breakdown leads to altered mandibular movement patterns during chewing function. Different attributes of representative JVA vibrations have been shown to indicate the presence of various disease states, often seen within the temporomandibular joint complex. After being recorded, the JVA software displays the various vibration waveforms for clinician analysis, to determine the specific internal derangement present. This chapter provides an overview of the various vibratory waveforms that indicate TM Joint pathology is present, and illustrates the utility of joint vibration analysis as a temporomandibular joint diagnostic adjunct. When this information is combined with a thorough clinical exam and medical history, a clinician can then begin to efficiently present the information to the patient. Significantly, proper communication begins with presenting information that is easily understood and familiar to the patient. A simplified approach utilizing a JVA-based diagnostic process, will be overviewed in detail.

A Simple Spot Weld Joint Finite Element Model for Vibration Analysis

Resistance spot welding is one of the commonly used structural joining processes in sheet metal structures. This paper presents the study of vibration characteristics of a spot-welded sheet metal coupon with a simple finite element model. The finite element spot weld nugget was modelled with Spider Configuration (SC) using commercial finite element code ABAQUS. Analytically the spot welded sheet metal coupon was modeled as a free–free Euler Bernoulli beam. Comparison was made for both natural frequencies and mode shapes of the first three bending modes between finite element model and analytical model. It was found that the simple finite element model was able to predict the spot weld joint vibration characteristics with a minimum of 0.35% and a maximum of 7.3% error.