Part Of Joint Research Articles

Dental practitioners’ knowledge, management practices, and attitudes toward collaboration in the treatment of temporomandibular joint disorders: a mixed-methods study

BackgroundTemporomandibular joint disorders (TMDs) are a variety of conditions that affect different parts of the temporomandibular joints (TMJ) and can cause orofacial pain and functional impairment. This study aims to investigate dental practitioners’ knowledge and management of Temporomandibular Joint Disorders (TMDs), particularly their knowledge of the role physical therapy plays in TMD treatment.MethodsA mixed-methods approach was adopted to provide a comprehensive view of current knowledge, management practices, and attitudes toward collaboration among dental practitioners in treating TMD. Data were collected from a convenience sample of 335 dentists in Karachi using a detailed questionnaire to assess their knowledge of the role of physical therapy in the treatment of TMD. Twenty dentists were chosen for face-to-face, in-depth interviews to explore their experiences and challenges in managing TMDs based on their responses to the administered questionnaire.ResultsThe cumulative quantitative and qualitative findings of the study revealed a landscape marked by individualized approaches to referral practices and significant gaps in interdisciplinary collaboration. Most practitioners holding a bachelor’s degree predominantly used medication (65.2%) and cause-specific treatment (65.3%) for TMD treatment. Thematic analysis of clinical efficacy and practitioner challenges in managing TMD revealed significant issues faced by dental professionals.ConclusionsThe study successfully validated a questionnaire to understand dental practitioners’ knowledge regarding physical therapy in TMD treatment. The study identified significant gaps in knowledge and a lack of collaboration between dentists and physiotherapists. The limited referral practices highlighted in the study, along with insights from dentist interviews, emphasize the need for improved interdisciplinary approaches to managing TMDs within dental practice.

On the influence of local deformation on structural dynamic models of bolted lap joints

The acoustic and structural dynamic behavior of technical products—often referred to as Noise, Vibration, and Harshness (NVH)—is an important criterion in customers’ purchasing decisions. Therefore, NVH optimization is a crucial goal of the development process. NVH is influenced by dynamic excitations, caused by time-varying forces e.g. in gears or electric machines, as well as the transfer path of sound from the location of excitation to a receiver such as a driver’s ear and the sound perception. The behavior of the transfer path is determined by amplification or isolation of structure-borne and airborne sound between the location of the excitation and the location of the receiver. As a result, eigenfrequencies and damping in the transfer path form crucial structural dynamic properties.Within jointed structures, friction between the surfaces of lap joints are the most dominant influencing factor on the transfer path’s damping. In order to increase the efficiency of NVH optimization in the development process, methods of virtual product development have become an established tool. Especially finite element method (FEM) and elastic multi-body simulation (eMBS) have allowed to numerically evaluate the structural dynamic behavior of technical products before manufacturing physical prototypes. While numerous methods for modeling jointed structures exist in FEM and eMBS environments, the choice of suitable eMBS models of joints remains challenging today. This is because the frictional behavior between the jointed partners in higher frequencies is largely influenced by the deformation of the joint surface. However, the deformation of the jointed parts is simplified in eMBS models compared to quasi-continuous FEM models. Accordingly, the choice of a suitable spatial discretization of eMBS joint models is a key factor in the model quality of eMBS models. Thus, this work proposes a modeling guideline for eMBS models of jointed structures based on the deformation of the structure using the criterion of rigidness. The method is demonstrated on an eMBS model of the academic Brake Reuß beam, which consists of two beam elements jointed with three screws in an overlap lap joint. Good agreement between eMBS simulation and measurement with an error of 1 dB is achieved using the proposed modeling method.

Effects of early debridement and conservative eschar removal followed by wound coverage with acellular dermal matrix in the treatment of children with deep burns

Effects of early debridement and conservative eschar removal followed by wound coverage with acellular dermal matrix in the treatment of children with deep burns

Optimal arrangement of AE sensors for prestressed hollow slabs based on AE propagation characteristics

Acoustic emission (AE) health monitoring is crucial for effective data collection, rational monitoring of results, and economical engineering applications in prestressed hollow slabs. To achieve an optimal sensor arrangement, experiments were performed to measure AE attenuation with different propagation paths in both the longitudinal and transverse directions of a full-scale prestressed hollow slab. Then, the AE amplitude and AE energy are chosen as evaluation indexes to investigate the hybrid arrangement of AE sensors under multiple damage conditions. The results indicate that when the AE signal propagates along the longitudinal direction of the prestressed hollow slabs with the same propagation distance, the attenuation in the steel strand is smaller. Additionally, the attenuation in the concrete directly under the bottom strand is smaller than that in the concrete between the bottom strands. The attenuation of AE propagation is smaller in the complete hinge than in the defective hinge. In terms of transverse propagation, the attenuation of AE signals is less in the bottom slab concrete than in the bottom slab steel strands. At the longitudinal 1/3 section of the prestressed hollow slab, the amplitude attenuation rate shows a turning point, and the variation in the attenuation rate of the AE signal is relatively small. For greater efficiency, it is recommended to position the sensors in the middle part of the hollow slab hinge joint and the bottom slab cross section, as well as on the concrete surface directly under the bottom slab strand.

Bioinspired wet adhesive carboxymethyl cellulose-based hydrogel with rapid shape adaptability and antioxidant activity for diabetic wound repair

Currently, adhesive hydrogels have shown promising effect in chronic diabetic wound repair. However, there are issues and challenges in treating diabetic wounds due to inadequate wet adhesion, unable to fill irregular and deep wounds, and oxidative stress. Herein, a mussel-inspired naturally hydrogel dressing with rapid shape adaptability, wet adhesion and antioxidant abilities for irregular, deep and frequently movement diabetic wounds repair was constructed by comprising catechol modified carboxymethyl cellulose (CMC-DA) and tannic acid. Benefiting from the reversible hydrogen bonding, the resulting hydrogels exhibited injectability, remarkable self-healing ability, rapid shape adaptability and strong tissue adhesion (45.9 kPa), thereby contributing to self-adaptive irregular-shaped wounds or moving joint parts. Especially, the adhesion strength of the hydrogel on wet tissue still remained at 14.9 kPa. Besides, the hydrogels could be easily detached from the skin by ice-cooling that avoided secondary damage caused by dressing change. Remarkably, the hydrogels possessed excellent antioxidant, satisfactory biocompatibility, efficient hemostasis and antibacterial properties. The in vivo evaluation further demonstrated that the hydrogel possessed considerable wound-healing promotion effect by regulating diabetic microenvironment, attributed to that the hydrogel could significantly reduce inflammatory response, alleviate oxidative stress and regulate neovascularization. Overall, this biosafe adhesive hydrogel had great potentials for diabetic wound management.

Joint modeling of an outcome variable and integrated omics datasets using GLM-PO2PLS

In many studies of human diseases, multiple omics datasets are measured. Typically, these omics datasets are studied one by one with the disease, thus the relationship between omics is overlooked. Modeling the joint part of multiple omics and its association to the outcome disease will provide insights into the complex molecular base of the disease. Several dimension reduction methods which jointly model multiple omics and two-stage approaches that model the omics and outcome in separate steps are available. Holistic one-stage models for both omics and outcome are lacking. In this article, we propose a novel one-stage method that jointly models an outcome variable with omics. We establish the model identifiability and develop EM algorithms to obtain maximum likelihood estimators of the parameters for normally and Bernoulli distributed outcomes. Test statistics are proposed to infer the association between the outcome and omics, and their asymptotic distributions are derived. Extensive simulation studies are conducted to evaluate the proposed model. The method is illustrated by modeling Down syndrome as outcome and methylation and glycomics as omics datasets. Here we show that our model provides more insight by jointly considering methylation and glycomics.

Giant cell tumour of tendon sheath (GCTTS) – 2 Most common tumour of hand after ganglion cyst

Probably one of the most common benign neoplasm in the human hand, the Giant Cell Tumour of Tendon Sheath (GCTTS) has been studied by many authors over the years as a popular tumour. There have been studies on the etilogical factors, however, limited attention has been given to etiology, prognostic factors, and recurrence rate. Because there are several factors that predispose to recurrence, it is imperative that medical practitioners ensure complete excision of the tumour, including removal of residual satellite nodules. This study is a focus on 0.5cm swelling over dorsal part of the interphalangeal joint of middle finger of the right hand of a 55-year old female that was initially unilobulated, which eventually increased to 3cm and was bilobed over 6 months. With meticulous dissection and the use of magnification loupe to obtain a low recurrence rate, thereby emphasising the key role of surgery as the first prognostic factor of GCTTS.

A NEW TYPE OF PLUG-IN FRICTION-STIR LAP WELDING BASED ON THE 6061-T6 ALUMINUM ALLOY

In this study a new type of plug-in friction-stir lap welding (PFSLW) is proposed to prepare welded joints based on 4-mm-thick 6061-T6 aluminum alloy sheet. The differences in the cross-sectional morphology, microstructure, cross-sectional hardness and shear properties between the PFSLW joint and the normal friction-stir lap-welding (FSLW) joint are discussed. The results show that the cross-sectional morphology of the PFSLW joint has undergone changes. The PFSLW joint has a mechanical interlocking structure on the advancing side that is beneficial to the connection strength of the joint. The grain structure differs at the boundary between the thermo-mechanically affected zone (TMAZ) and the heat-affected zone (HAZ), and the PFSLW joints show a more pronounced bending deformation of the grain organization near the boundary. The microhardness of PFSLW joints was increased in the TMAZ and HAZ areas, and the lowest hardness is further away from the center of the weld. The failure load of the PFSLW joint has been improved, the microcracks part of the PFSLW joint has a ridge-like structure. In addition, the actual welding width of PFSLW joints was improved.

Possibilities of analyzing the mechanical properties of welded and soldered joints

During a tensile test of a welded and soldered joint, the sample is broken at the point of least strength or at the point of the defect. If there is a violation in the base material, the joint is evaluated as satisfactory, but we do not get an overview of the strength of the individual parts of the welded joint and also of the soldered joint, and thus it is not possible to measure the strength in a predetermined part of the welded joint and also the strength of the soldered joint. An option to measure this property is to measure the shear strength in any predetermined part of the weld joint. It is thus possible to measure the shear strength of butt weld joints in the base material, in various zones of the heat-affected zone, in the weld metal, and also in lap weld and soldered joints. The possibilities of analyzing the mechanical properties in the mentioned way were verified on butt and lap copper - stainless steel joints created by electron beam welding and laser beam welding. The joints before and after the test were metallographically analyzed.

Peripheral nerve regeneration following scaffold-free conduit transplant of autologous dermal fibroblasts: a non-randomised safety and feasibility trial

BackgroundThe use of Bio 3D nerve conduits is a promising approach for peripheral nerve reconstruction. This study aimed to assess their safety in three patients with peripheral nerve defects in their hands.MethodsWe describe a single institution, non-blinded, non-randomised control trial conducted at Kyoto University Hospital. Eligibility criteria included severed peripheral nerve injuries or a defect in the region distal to the wrist joint not caused by a congenital anomaly; a defect with a length of ≤20 mm in a nerve with a diameter ≤2 mm; failed results of sensory functional tests; ability to register in the protocol within 6 months from the day of injury; refusal of artificial nerve or autologous nerve transplantation; age 20–60 years; and willingness to participate and provide informed written consent. Six weeks before transplantation, skin was harvested, dermal fibroblasts were isolated and expanded, and Bio 3D nerve conduits were created using a Bio 3D printer. Bio 3D nerve conduits were transplanted into the patients’ nerve defects. The safety of Bio 3D nerve conduits in patients with a peripheral nerve injury in the distal part of the wrist joint were assessed over a 48-week period after transplantation.ResultsNo adverse events related to the use of Bio 3D nerve conduits were observed in any patient, and all three patients completed the trial.ConclusionsBio 3D nerve conduits were successfully used for clinical nerve reconstruction without adverse events and are a possible treatment option for peripheral nerve injuries.

Modified Ludloff's medial approach for resection of heterotopic ossification of the hip following severe SARS-CoV-2 infection: a case report.

The coronavirus disease 2019 pandemic has significantly affected people worldwide. Herein, we present a case of massive heterotopic ossification (HO) of the right hip following severe SARS-CoV-2 infection. The exact origin of HO development is still unknown, but a critical illness, chronic immobilization and hypoxia are important risk factors. Considering the location and size of the HOs in this case, modified Ludloff's medial approach of the hip was used. This approach allows for good exposure and access to the medial and inferior part of the hip joint and the successful extirpation of the pathologic tissue.

Клинический случай мономиелической формы мелореостоза (болезнь Лери — Жоани)

The article presents a clinical case of melorheostosis with lesion of the left lower limb in a 30-year-old woman, involving the hip, knee joints, and foot lesion. Arthrotomy with removal of osteophytes in the posterior part of the knee joint and removal of osteophytes of the foot were performed. In the postoperative period, peroneal nerve neuropathy developed, which required neurolysis and a course of conservative treatment; the neuritis resolved. Later, total hip arthroplasty of the left hip joint was performed and the function of the limb was restored. New surgical interventions may be required in the future.

Features of the macroscopic structure of the posterior inferior tibiofibular ligament based on anatomical study.

Aim: To study the anatomy of the posterior inferior tibiof i bular ligament (PITFL) and specify the features of its morphology and linear parameters. Materials and Methods: The peculiarities of morphology and linear parameters of PITFL on 10 fresh amputated lower limbs were studied. The average age of the patients was 64.7 ± 9.3 (7 males, 3 females). Macroscopic characteristics, insertion, orientation in relation to the corresponding bony and ligamentous anatomical structures were studied, and linear parameters of PITFL were measured using a caliper. Average values were calculated. Results: PITFL was detected in all the studied samples. It represented a strong, compact anatomical structure of a trapezoidal or triangular shape. The proximal width of the PITFL averaged 20 ± 3.65 mm, while the distal width was 36.6 ± 4.62 mm. The attachment length of PITFL to the posterior part of the tibia was 28.6 ± 5.13 mm and to the fi bula was 17.4 ± 3.2 mm. The ligament is closely connected to the posterior intermalleolar ligament, the inferior transverse ligament, and the tendinous sheaths of the posterior tibial and fi bular muscles. Conclusions: The obtained results of the study of linear and morphological parameters of PITFL should contribute to a better understanding of the anatomy of the posterior part of the ankle joint and improve surgical approaches to the treatment of posterior malleolus fractures and related PITFL injuries.

Comprehensive Guidance for the Prevention of Periprosthetic Joint Infection After Total Joint Arthroplasty and Pitfalls in the Prevention.

Total joint arthroplasty (TJA) is a surgical procedure, in which parts of damaged joints are removed and replaced with a prosthesis. The main indication of TJA is osteoarthritis, and the volume of TJA is rising annually along with the increase of aged population. Hip and knee are the most common joints, in which TJAs are performed. The TJA prosthesis is composed of metal, plastic, or ceramic device. Even though TJA is the most successful treatment for end-stage osteoarthritis, it is associated with various complications, and periprosthetic joint infection (PJI) is the most serious complication after TJA. With the increasing volume of TJAs, there is a simultaneous rise in the incidence of PJI. Contamination of the surgical wound and the adherence of bacteria to the surface of prosthetic component represent the initial step in the pathogenesis of PJI. The main sources of the contamination are 1) patient's own flora, 2) droplets in the operation room air, and 3) surgical gloves and instruments. Even though modern techniques have markedly reduced the degree of contamination, TJAs cannot be done in completely germ-free conditions and some degree of contamination is inevitable in all surgical procedures. However, not all contamination leads to PJI. It develops when the burden of contamination exceeds the immune threshold or the colony forming units (CFUs) and various factors contribute to a decrease in the CFU level. Surgeons should be aware of the germ burden/CFU concept and should monitor sources of contamination to maintain the germ burden below the CFU to prevent PJI.

Оценка напряженнодеформированного состояния профильных соединений узлов машин

The article presents the results of studies of profile joints of mechanisms and machines for rigidity and strength. The device is based on the use of fixed and movable profile connections designed to transmit torque. Profile joints with a guaranteed gap are considered, made on the basis of an equiaxial contour of the P3, P5 type and a curved contour of the PC4 type, which have received the most widespread introduction in the nodes of metal-cutting machines and other machines manufactured in Russia, as well as Hungary, Germany and the DPRK. Using a well-known technique designed to assess the stress-strain state (VAT) of the parts of profile joints, calculations are performed according to the criteria of operability for strength and stiffness of hubs (bushings) with different wall thicknesses. The analysis of the results of the calculation of strength and stiffness is carried out using the example of the P3 profile. When stretching the hub from the action of spacer forces, the geometric shape, the nominal size of the covered part, the wall thickness of the covering part, as well as the magnitude of the external load transmitted by the connection in static are taken into account. The permissible values of the thickness of the walls of the hub (bushings) of the joint are determined to ensure the rigidity of the hub under tension from the action of external loads. As a result of the research, the influence of the thickness of the hub walls for the studied shapes of the joint parts on the values of the transmitted torque is established. For example, a change in the thickness of the hub wall from 15 to 3 mm for a normal range of shaft mounting diameters causes the sleeve to stretch radially up to 50 microns in the range of transmitted torques from 5 to 600 Nm.

Justification of the effect of the regularities of the flow of nanotribological processes in the materials of joint parts on the increase of wear resistance, reliability and efficiency of the functioning of machines and mechanisms

The article elucidates the essence of nanotribological processes in the materials of conjugation of samples of parts by the methods of the surface force apparatus, scanning tunneling and atomic force microscopy. The substantiation of the mechanisms of their occurrence is given by the methods of molecular dynamics and classical contact mechanics. Attention is paid to dry adhesive and contactless dynamic friction of conjugated samples, physical processes in "sticking-sliding" tribocontacts, adhesive effects, etc. The values of the lateral and normal forces acting on the probe were analyzed. The probe was considered as a collection of point particles of concentrated mass with a multiatomic structure of the material. The contact and movement of the probe with the surface of the sample was considered in the "probe-surface" system with minimal potential energy and lateral load and taking into account conservative and dissipative forces.
 The effect of "sticking-sliding" is substantiated with the help of the apparatus of surface forces. The atomic periodicity of the effect is explained on the basis of the model of the formation and breaking of adhesive bonds and the "atom-magnet" model. It is shown that the patterns of "sticking-sliding" processes can be determined by using the parameters of shear stress and specific work of adhesion.
 It is advisable to use the Johnson-Kendall-Roberts theory to explain the elastic adhesive contacts, and the Deryagin-Mullier-Toporov theory for the residual friction force and probe separation force.
 It is shown that there is a significant connection between friction and adhesion processes. The correlation between the macroscopic value of the surface energy of materials and their shear modulus for homogeneous contacts was determined.
 On the basis of adhesive effects and the effect of "sticking-sliding", it is possible to control frictional forces and create favorable conditions for their absence, which gives grounds for obtaining high wear resistance of tribo-joints of parts, their reliability and maximum efficiency of the functioning of machines and mechanisms

The mechanical behaviour of a slip joint for an offshore wind turbine: First monitoring and modelling results

This study aims at shedding light on the mechanical behaviour of a prototype monopile–wind turbine tower connection, constituted by a slip joint. Selected examples of data set recorded during a long term monitoring campaign are illustrated and discussed. The data set encompass axial and hoop stresses measured over the slip joint area, relative displacements of the slip joint with respect to the monopile and acceleration levels recorded above the slip joint. In parallel, an ideal and simplified Finite Element model (FEM) of the slip joint is developed, in order to interpret the observed experimental data. Experiments first highlight the relevance of modelling the manufacturing imperfections of the overlapping steel sections. Subsequently, both experiments and FEM show that states of prestress need to be accounted for. Such prestress states first originate from the installation process, and subsequently from further loading events, triggering settlements of the slip joint. Finally, experiments and FEM showcase the force transfer mechanisms from the upper part to the lower part of the slip joint.

MODERNIZATION OF MOVEABLE CONNECTIONS OF THE SECTION OF THE SOWING COMPLEX

The efficiency of planting seeds and, therefore, the yield of agricultural crops depend significantly on the characteristics of the mechanisms of copying sowing sections. These mechanisms can be conditionally divided into two categories: radial and parallelogram. Radial mechanisms with leashes are used in traditional technologies and require high-quality preliminary processing, and radial mechanisms with pressure rods are suitable for any agrophones The durability of the movable joints of the parallelogram copying mechanism of the sowing complex depends on their resistance to wear. This stability is determined by the mode of operation, chemical composition and structure of the surface layer of parts, as well as physical-mechanical and tribotechnical characteristics. With an average seasonal task for Agro-Soyuz Turbosem II 19-60 sowing complexes within 3–4 thousand hectares, the total service life of experimental parts is at least 4 years, which is at least four times more than in the case of serial parts. The positive effect of the absence (or the presence within the measurement error) of wear of steel parts of movable joints that work in connection with polymer composite material (PCM) was revealed. The average resource of experimental parts in the hinges of the parallelogram copying mechanism for Agro-Soyuz Turbosem II 19-60 seeding complexes is 20589 ha. The average value of the wear of the experimental parts was determined to be 1.78 mm, and the intensity of their wear was 1.02×10-4 mm/ha. It was established that the wear of UPA-6-30 PCM parts in the moving joints of the copying mechanism occurs according to the normal distribution law ( = 0.108), which allows very accurate prediction of their resource. The consistency of the experimental distribution with the theoretical distribution was checked using the Kolmogorov criterion. It is confirmed that the distribution takes place according to the normal law. An analysis of reliability indicators during shortened tests was also carried out and the probability of failure-free operation of experimental parts made of polymer-composite material was determined. According to the results of field tests of the elements of the movable joints of the mechanism of copying the sowing complex, it was established that the resource value of 20,558 hectares exceeds the indicators of serial parts by 4 times.

The Design and Mechanical Study of the Pipe Joint Structure in a High-pressure Hydraulic System

Pipe joints are important connecting devices and weak links in high-pressure hydraulic systems, and their rational design is of great significance for ensuring the safety of hydraulic transmission systems. In accordance with the requirements of high-pressure hydraulic oil systems, a 70 MPa high-pressure oil pipe structure was designed, and strength and sealing analyses were conducted by using the finite element module in SolidWorks simulation. The results showed that the stress distribution in various parts of the pipe joint was relatively uniform and achieved an elastic-plastic sealing effect. The radius of curvature on the outer wall of the pipe is a key factor in joint design, and the connectivity performance of the joint can be adjusted by the axial displacement of the connector. The sealing tests demonstrated that the pipe design meets the structural strength and sealing performance requirements for use at 70 MPa. The research findings provide references for optimizing the design, manufacturing, and installation of pipe joints in high-pressure hydraulic systems.

Static behaviour of the selected carpentry joints in the flexural elements

The paper presents the static behaviour of the selected carpentry joints in the bending wooden elements. Experimental research on beams with the carpentry joints created according to the geometry of the historical joints was conducted. It was confirmed that some of the longitudinal joints applied in the historical structures, with the proper strengthening elements, could transfer some bending moments, which is important in the flexural elements. The load-carrying capacity of the joined beams was determined and compared to the load-carrying capacity of the reference continuous beams, which was from 30 % to 40 %, depending on the joint geometry. Moreover, the stiffness level of the joined beams was determined and compared to the stiffness of the reference continuous beams, which was from 35 % to over 60 %, also depending on the joint geometry. The force-deflection plots for the tested beams were presented. The failure patterns for the joints were described and based on them the areas of stress concentrations in the joints were identified. The joints worked asymmetrically and their failure occurred as a result of gradual loosening and then cracking – interruption of the continuity of the wood fibres. The role of the applied fasteners, which to some extent protect against loosening of the joints, and partially transfer the applied load, was confirmed. The obtained results were compared to the results from the literature regarding similar connections. Research results can be helpful in designing and performing repair and conservation work in historic wooden structures with carpentry joints, in the event of, for example, the need to recreate a historical joint or replenish part of the substance in an existing joint.