scholarly journals Identification of Biomechanical Properties of Temporomandibular Discs

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Edward Kijak ◽  
Jerzy Margielewicz ◽  
Małgorzata Pihut
Keyword(s):  
Temporomandibular Joint ◽  
Testing Machine ◽  
Biomechanical Properties ◽  
Measurement Range ◽  
Disc Tissue ◽  
Temporomandibular Joints ◽  
Calculation Results ◽  
Numeric Calculation ◽  
Joint Discs ◽  
Selection Of

Purpose of the Paper. The study was aimed at identifying the biomechanical properties of the temporomandibular disc. Material. Experimental and model tests were conducted on ten fresh porcine temporomandibular joint discs. The average thickness of disc tissue was, accordingly, 2.77 mm for the anterior zone, 3.98 mm for the posterior, and 1.54 mm for the intermediate. The selection of research material in the form of porcine discs was due to the similarity to human discs. Methods. Discs were loaded in cycles, a temporary course with the amplitude 3 N and frequency 0.07 Hz, and growth in the load was 1 N/s. The selection of load frequency was due to real conditions of temporomandibular joint functioning during mastication. The necessary experimental research was conducted on a testing machine with a measurement range of 2.5 kN. Results. The obtained numeric calculation results indicate that the number of load cycles has a decisive impact on the limitation of energy dispersion capacity through disc tissue. This phenomenon was observed in all the studies on the disc areas. Along with the growth in load cycles, discs are stiffened, and the most significant stiffness was observed in the intermediate area. Conclusions. Based on the conducted research, it should be concluded that excessive load affecting temporomandibular joints caused by the act of mastication and occlusal forces generated during parafunction and in people with defined long-term bruxism has crucial importance on biomechanical disc properties and hence the course of temporomandibular joint conditions.

Biomechanical Evaluation of the Medial Stabilizers of the Patella

2018 ◽  
Vol 46 (7) ◽  
pp. 1575-1582 ◽  
Author(s):  
Matthew D. LaPrade ◽  
Samantha L. Kallenbach ◽  
Zachary S. Aman ◽  
Gilbert Moatshe ◽  
Hunter W. Storaci ◽  
...  
Keyword(s):  
Ultimate Load ◽  
Testing Machine ◽  
Biomechanical Properties ◽  
Patellar Ligament ◽  
Anatomic Reconstruction ◽  
Bony Avulsion ◽  
Significant Difference ◽  
The Mean ◽  
Mechanism Of Failure ◽  
Selection Of

Background: Quantification of the biomechanical properties of each individual medial patellar ligament will facilitate an understanding of injury patterns and enhance anatomic reconstruction techniques by improving the selection of grafts possessing appropriate biomechanical properties for each ligament. Purpose: To determine the ultimate failure load, stiffness, and mechanism of failure of the medial patellofemoral ligament (MPFL), medial patellotibial ligament (MPTL), and medial patellomeniscal ligament (MPML) to assist with selection of graft tissue for anatomic reconstructions. Study Design: Descriptive laboratory study. Methods: Twenty-two nonpaired, fresh-frozen cadaveric knees were dissected free of all soft tissue structures except for the MPFL, MPTL, and MPML. Two specimens were ultimately excluded because their medial structure fibers were lacerated during dissection. The patella was obliquely cut to test the MPFL and the MPTL-MPML complex separately. To ensure that the common patellar insertion of the MPTL and MPML was not compromised during testing, only one each of the MPML and MPTL were tested per specimen (n = 10 each). Specimens were secured in a dynamic tensile testing machine, and the ultimate load, stiffness, and mechanism of failure of each ligament (MPFL = 20, MPML = 10, and MPTL = 10) were recorded. Results: The mean ± SD ultimate load of the MPFL (178 ± 46 N) was not significantly greater than that of the MPTL (147 ± 80 N; P = .706) but was significantly greater than that of the MPML (105 ± 62 N; P = .001). The mean ultimate load of the MPTL was not significantly different from that of the MPML ( P = .210). Of the 20 MPFLs tested, 16 failed by midsubstance rupture and 4 by bony avulsion on the femur. Of the 10 MPTLs tested, 9 failed by midsubstance rupture and 1 by bony avulsion on the patella. Finally, of the 10 MPMLs tested, all 10 failed by midsubstance rupture. No significant difference was found in mean stiffness between the MPFL (23 ± 6 N/mm2) and the MPTL (31 ± 21 N/mm2; P = .169), but a significant difference was found between the MPFL and the MPML (14 ± 8 N/mm2; P = .003) and between the MPTL and MPML ( P = .028). Conclusion: The MPFL and MPTL had comparable ultimate loads and stiffness, while the MPML had lower failure loads and stiffness. Midsubstance failure was the most common type of failure; therefore, reconstruction grafts should meet or exceed the values reported herein. Clinical Relevance: For an anatomic medial-sided knee reconstruction, the individual biomechanical contributions of the medial patellar ligamentous structures (MPFL, MPTL, and MPML) need to be characterized to facilitate an optimal reconstruction design.

PREDIKSI PENERIMAAN KARYAWAN BAGIAN DESAIN PADA EVENT ORGANIZER PT. SEIRAH WISATA MENGGUNAKAN ALGORITMA C4.5

2021 ◽  
Vol 5 (1) ◽  
pp. 28-32
Author(s):  
Hendriyanto , Bei harira
Keyword(s):  
Human Resources ◽  
Extensive Experience ◽  
Gain Ratio ◽  
Vital Part ◽  
C4.5 Algorithm ◽  
Calculation Results ◽  
Selection Of

ABSTRACT Human resources design section at an Event Organizer is a vital part considering that the design will be seen by the event participants in addition to the technical events. The selection of employees who understand design and have extensive experience is important. The process of selecting employees in the design field can sometimes be difficult to predict if there are several prospective employees with balanced abilities. From the calculation results of the dataset as many as 14 applicants using the C4.5 algorithm, the highest Gain Ratio value obtained in the design Ability and Experience = 0.7172, Origin of Schools = 0.0511 and Age = 0.0205. Keywords : event organizer, C4.5 algorithm, prospective employees, Gain Ratio

scholarly journals Determination of Nearest Emergency Service Office using Haversine Formula Based on Android Platform

2018 ◽  
Vol 5 (2) ◽  
pp. 270-278 ◽  
Author(s):  
M. Basyir ◽  
M. Nasir ◽  
Suryati Suryati ◽  
Widdha Mellyssa
Keyword(s):  
Emergency Service ◽  
Emergency Services ◽  
Message Delivery ◽  
Test Results ◽  
Average Delay ◽  
Accuracy Test ◽  
Calculation Results ◽  
Testing Accuracy ◽  
Selection Of

Emergency Reporting Application is an android-based application that serves to help the community in reporting the emergency condition. This application allows users to choose and contact the emergency services office, without the need to notice their position and phone number. Selection of emergency services office is also automatically selected by the system by taking into account the distance between the complainant and the emergency services office. The selected emergency services office is the nearest emergency service office from the complainant so that the delay in coming assistance can be minimized. Therefore, this proposed application requires a GPS feature to recording, reporting and SMS positioning for message delivery of reports. The distance between the position of the complainant and the position of the emergency service office, in the form of latitude and longitude data, is requested using the Haversine formula taking into account the degree of curvature of the earth. Emergency service offices include police and hospital offices spread over 25 different districts. Furthermore, the reporter's position calculation results were compared with all selected emergency service offices and obtained 1 nearest emergency service office. Calculating the accuracy and delay value of the system will do system testing. Accuracy test results using the method of 100% Haversine and the average delay of the system is 4.5 seconds.

scholarly journals A Morphometric Analysis of Intra-articular Disc of Temporomandibular Joints in Cadavers

2021 ◽  
Author(s):  
Pratik Ashokkumar Agrawal ◽  
Navin S Shah ◽  
Ramnarayan A Gandotra ◽  
Karan Vasantray Panchal ◽  
Rishabh Navin Shah
Keyword(s):  
Temporomandibular Joint ◽  
Anatomic Variation ◽  
Maxillofacial Surgery ◽  
Temporomandibular Joint Disorders ◽  
Research Centre ◽  
Oral And Maxillofacial Surgery ◽  
Articular Disc ◽  
Chi Square ◽  
Temporomandibular Joints ◽  
Human Cadavers

Introduction: Temporomandibular Joint (TMJ) has been a controversial topic in Oral and Maxillofacial Surgery speciality especially regarding temporomandibular joint disorders and internal derangement of articular disc. The aetiology behind it has been related to the anatomic variations of the disc and its impact on the functioning of the articular disc. To understand such anatomic variation, the study has been conducted that will help future maxillofacial surgeon’s in designing accurate prosthetic articular disc that will improve the overall mechanics of the functioning of the prosthetic disc. Aim: To analyse the morphometric variations of the intra-articular disc in terms of circumference of the disc, perforations and their thickness within the disc in cadavers. Materials and Methods: The present observational study was carried out on cadavers in the Department of Anatomy. SBKS Medical College and Research Centre, Sumandeep Vidyapeeth University, Gujarat, India. The study was done from January 2017 to October 2018. Temporomandibular joints were dissected bilaterally from 10 human cadavers, i.e., 20 articular discs. The disc was removed and was measured with the help of thread, vernier callipers and standardised metallic scale and the circumference and thickness in the disc were evaluated. Descriptive statistical test was used and Chi-square test was applied. Results: Mean thickness of disc, both in males as well as females ranged from 1.4-2.0 mm in the Posterio-Medial (PM) and Posterio- Lateral (PL) region, while in Anterio-Medial (AM) and Anterio- Lateral (AL) region it ranged from 1.6-1.8 mm. Maximum length of disc ranged from 12-13 mm in anterio-posterio dimension while in Medio-Lateral (ML) it was 22-23 mm. Conclusion: The study gives an indepth knowledge about the various morphometric variations of articular disc and also shows its impact on the functioning of the disc. The study also directs maxillofacial surgeons to design prosthetic articular disc with greater accuracy and anatomical knowledge so that the procedures like surgical replacement of the disc can be carried out with greater potency and efficacy for the betterment of the patient.

scholarly journals Tensile biomechanical properties of human temporomandibular joint disc: Effects of direction, region and sex

2016 ◽  
Vol 49 (16) ◽  
pp. 3762-3769 ◽  
Author(s):  
Gregory J. Wright ◽  
Matthew C. Coombs ◽  
R. Glenn Hepfer ◽  
Brooke J. Damon ◽  
Thierry H. Bacro ◽  
...  
Keyword(s):  
Temporomandibular Joint ◽  
Biomechanical Properties ◽  
Temporomandibular Joint Disc

Численные подходы к решению нелинейной системы уравнений Шрёдингера для распространения волн в оптическом волокне

2020 ◽  
Author(s):  
A.J. Sakhabutdinov ◽  
V.I. Anfinogentov ◽  
O.G. Morozov ◽  
R.R. Gubaidullin
Keyword(s):  
Finite Difference ◽  
Nonlinear Term ◽  
Initial Boundary ◽  
Equation System ◽  
Integration Scheme ◽  
Integration Step ◽  
Disturbance Propagation ◽  
Calculation Results ◽  
Definition Of ◽  
Selection Of

The paper discusses approaches to the numerical integration of the second-kind Manakov equation system. Emphasis is placed on the transition from writing equations in dimensional quantities to equations in dimensionless units. A combined explicit/implicit finite-difference integration scheme based on the implicit CrankNicolson finite-difference scheme is proposed and substantiated, which allows integrating a nonlinear system of equations with a choice of nonlinear term at the previous integration step. An algorithm for leveling the disadvantage associated with the definition of the nonlinear term from the previous integration step is proposed. The approach of automatic selection of the integration step, which reduces the total number of integration steps while maintaining the required accuracy of the approximate solution, is substantiated. Examples of the calculation results for some values of the disturbance propagation are given. The limitations imposed by the computing scheme on the length of the integrable fiber section are described, and approaches, that eliminate these limitations without the need to increase arrays dimensions, are proposed. Requirements for initial boundary conditions are discussed. Предложена разработка метода приближенного решения системы уравнения Манакова как одного из частных случаев системы уравнений Шрёдингера, связанного с моделированием оптических линий связи на основе многомодовых волокон. Решение ищется методами численного интегрирования. Показано, что численное интегрирование может быть осуществлено с использованием комбинированной явно-неявной схемы численного интегрирования на основе схемы КранкаНиколсон с записью нелинейного слагаемого в конечно-разностной форме, взятого с предыдущего шага интегрирования. Использован алгоритм автоматического выбора шага интегрирования, реализован итерационный алгоритм уточнения решения на каждом шаге, предложен алгоритм, позволяющий производить расчет параметров на протяженных участках. Нахождение приближенного решения системы уравнения Манакова может быть осуществлено с использованием комбинированной явно-неявной схемы КранкаНиколсон, а запись нелинейного слагаемого в конечно-разностной форме, взятого с предыдущего шага интегрирования, дает неплохой результат. Алгоритм автоматического выбора шага интегрирования обеспечивает лучшую сходимость результатов интегрирования на большом расстоянии и снижение необходимого количества шагов интегрирования. Алгоритм уточнения решения на каждом шаге позволяет нивелировать недостаток метода явной записи неявного слагаемого и интегрировать с большим шагом. Алгоритм расчета параметров распространения возмущения со сдвигом фрейма позволяет сделать вывод о целесообразности развития этого алгоритма.

Аpplication of the mathematical model of human torso for modeling abbreval influence in wound ballistics

2020 ◽  
Vol 22 (3) ◽  
pp. 132-139
Author(s):  
A. V. Denisov ◽  
M. D. Stepanov ◽  
N. A. Haraldin ◽  
A. V. Stepanov ◽  
A. I. Borovkov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Element Model ◽  
Mechanical Action ◽  
Calculation Model ◽  
Calculation Results ◽  
Automated Processing ◽  
Original Calculation ◽  
Using Data ◽  
The Mathematical Model ◽  
Selection Of

Abstract. In the work, a review of scientific articles on the behavior of tissues and organs of the human body under local mechanical effects on it, as well as a description of the physico-mechanical properties of biological materials. The selection of mechanical behavior for each biological material as part of a mathematical model of the human torso was carried out, its finite element model was created, validation experiments were modeled using data presented in the literature. An original calculation model of a human torso with a tuned interaction of organs with each other was developed. Contact interaction parameters are determined. The developed computational model of a human torso was verified based on data from open sources for an experiment with mechanical action by a cylindrical impactor. An algorithm for processing pressure and acceleration graphs has been implemented in order to obtain tolerance curves. A specialized modular program has been created for the automated processing of calculation results and the output of the main results. 42 numerical tests were carried out simulating the entry of a steel ball into each of 21 zones for power engineers of 40 and 80 J. According to the results of the tests for each organ, pressure and acceleration tolerance curves were obtained, animations of the behavior of organs under shock were created, visualization of the pressure field propagation in organs was obtained torso.

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