• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.158-164
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• 2019

The interbody fusion cage used to replace the degenerative intervertebral disc is largely composed of titanium-based biomaterials and biopolymer materials such as PEEK. Titanium is characterized by osseointergration and biocompatibility, but it is posed that the phenomenon such as subsidence can occur due to high elastic modulus versus bone. On the other hand, PEEK can control the elastic modulus in a similar to bone, but there is a problem that the osseointegration is limited. The purpose of this study was to implement titanium material's stiffness similar to that of bone by applying cellular structure, which is able to change the stiffness. For this purpose, the cellular structure A (BD, Body Diagonal Shape) and structure B (QP, Quadral Pod Shape) with porosity of 50%, 60%, 70% were proposed and the reinforcement structure was suggested for efficient strength reinforcement and the stiffness of each model was evaluated. As a result, the stiffness was reduced by 69~93% compared with Ti6Al4V ELI material, and the stiffness most similar to cortical bone is calculated with the deviation of about 12% in the BD model with 60% porosity. In this study, the interbody fusion cage made of Ti6Al4V ELI material with stiffness similar to cortical bone was implementing by applying cellular structure. Through this, it is considered that the limitation of the metal biomaterial by the high elastic modulus may be alleviated.

• Journal of International Academy of Physical Therapy Research
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• v.7 no.2
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• pp.989-993
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• 2016

The purpose of this study was to investigate the effects of occipital bone stimulation by cervical stabilizing exercise on the muscle tone, stiffness, ROM, and cervical lordosis in patient with forward head posture(FHP). This study was a case study of a single patient with forward head posture. This study used a ABA' design, A and A' were the baseline phases and B was the intervention phase. The intervention was occipital bone stimulation by cervical stabilization exercise. It was administered once daily for 7 days. The therapist kept hands together, and placed the two index fingers under the subject's occipital bone. The subject performed the chin-in exercise with a maximum isometric contraction for 20 sec.The exercise was implemented by performing the movements 10 times as a set and repeating the set three times. The muscle tone was not significantly changed after intervention. However, the stiffness was decreased and lasted the effect lasted without intervention. The cervical flexion angle was increased, but the cervical extension angle was not significantly changed after the intervention. The left and right lateral flexion angles were increased and the effect lasted without any intervention. However, the left and right rotation angles were significantly changed after the intervention. Cervical lordosis increased not from $37^{\circ}$ to $41^{\circ}$ after the intervention. These results suggest that occipital bone stimulation by cervical stabilizing exercise had a positive effect on cervical stiffness, flexion and lateral flexion ROM, and lordosis in a patient with forward head posture.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.97-99
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• 2000

Considerable beneficial effects on osteoporosis from soy intake in postmenopausal women are being reported (Murkies et al.1998, Arjmandi et al. 1996). Isoflavones(IF), one of phytoestrogenic substances in the soybean, have been suggested for the effect. Our preliminary study showed that even the young chicks fed IF-rich diet tended to have higher bone ash content than those fed IF-poor diet. IF have been reported to decrease bone ash content than those fed IF-poor diet, IF have been reported to decrease bone loss by reducing bone resorption. Soybean meal has been one of the most important protein sources in poultry diets. We assume that the IF intake through dietary soybean meal could give meaningful influences on the birds. This study was carried out to determine effects of dietary IF from soybean sources on bone development in young chicks. Soy protein concentrate (SPC, IF-poor)and an IF concentrate(Phyto-Nutramin) were formulated together with purified-type ingredients to provide three different levels(25, 240 and 480 mg/kg) of total IF. Control diet(240 mg/kg) was prepared with isolated soyprotein(ISP, IF-rich). The diets were fed to 96, 3-day old, layer-type, male chicks, divided into 4 treatments with 3 replications for 3 weeks. Chicks fed the ISP diet had better gain/feed ratios than fed the SPC diets. Birds fed the diets with higher levels of IF tended to show higher values in serum total and ionized Ca% and tibial bone density, length % ash, stiffness and strain. This trend however, appeared less significant at the end of third week. No noticeable differences in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in sizes of comb and testicle and serum alkaline phosphatase activities were observed among the dietary groups. These results suggest that dietary isoflavones from soybean sources could be associated with chemical composition and physical properties of bone in young chicks.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.296-326
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• 1994

The purpose of this study was to evaluate the mechanical effects when one implant fixture was connected to the natural teeth with reduced alveolar bone height. This study also examined the effects of increasing the number of abutment teeth and the effects of the intramobile connector and the titanium connector as they were inserted between the implant superstructure and the fixture. The distribution and concentration load was applied to the fixed partial denture(FPD) supported by implant and the natural teeth with reduced alveolar bone height. The stress and displacement of each element was observed and compared by the two-dimensional finite element method. The following results were obtained : 1. The greater the loss of alveolar bone in natural teeth area, the greater the displacement of FPD and the stress concentration in alveolar bone around implant, especially at the stress concentration in the mesial alveolar bone crest around implant fixture. 2. The displacement of FPD was increased more and that of implants fixture was decreased more when intramobile connector was used than titanium connector was used. Also the stress concentration in alveolar bone around implant fixture was greater when intramobile connector than titanium connector. One implication of this finding was that the difference in stiffness of implant and the natural teeth with reduced alveolar bone height could be partially compensated in case of the POM intramobile connector. 3. The amount and direction of displacement and the stress distribution of the 4-unit FPD was better than those of the 3-unit FPD. It implied that the difference of stiffness of implant and natural teeth with reduced alveolar bone height could be partially compensated in case of the 4 unit FPD.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.129-150
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• 1993

Since the restoration or masticatory function is the most important aim of implants, it should be substituted for the role of natural teeth and deliver the stress to the bone under the continous load during function. In natural teeth, stress distribution can be obtained through enamel, dentin and cementum and the elasticity of the periodontal ligament play a role of buffering action. In contrast, implant prosthesis has a very unique characteristics that it delvers the load directly to bone through the implant and superstructure. This fact arise the needs to evaluate the stress distribution of the implant in the mechnical aspects, which has a similar role of natural teeth but different pathway of stress. With 3 kinds of implant in prevalent use, 2 types of experimental PEA implant models were made, axisymmetric and 2-dimensional type. In axisymmetric model, the stiffness of the part including the prosthesis and implant which extrude out of bony surface could be calculated with displacement of the superstructure un er 100N vertical load and then damping effects could be determined through this stiffness. In axisymmetric FEA model, load to the bone could be deduced by evaluation the stress distribution of the designed surface under the 100N vertical force and in 2-dimensional model, 100N eccentric vertical load and 20N horizontal loda. The result are as follows. 1. In every implant, stress to the bone tends to be concenturated on the cortical bone. 2. Though the stress of the cancellous bone is larger at the apex of implants, it is less compared with cortical bone. 3. Under 20N horizontal load, stress of the left and right sides of implant shows a symmetrical pattern. But under 100N eccentric vertical load, loaded side shows much larger stress value. 4. In the 1mm interface, stress distribution among implants tend to have a similar pattern. But under 20N horizontal load apposite side of being loaded shows less stress in IMZ. 5. In the case of screw type implant, stress tends to vary along with screw shape. 6. According to the result determined with microstrain, cancellous bone id generally under the condition of overload, while cortical bone is usually within the limitation of physiologic load. 7. In the Branemark implant, maximum stress to the cortical bone is larger than any other implant except for the condition of 20N horizontal force and 0.05mm interface. 8. Damping effects of implants is maximum in IMZ.

• Journal of muscle and joint health
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• v.15 no.1
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• pp.88-95
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• 2008

Purpose: This study was to evaluate and compare the effectiveness of the Resistance Exercise Program on pain, stiffness, ADL and bone mineral density in Arthritis Patients at home. Methods: Forty-two patients participated in this study and they were divided randomly into two groups (exercise and control group). Two subjects dropped during the study period. The exercise group had a structured training which was 50 minutes in duration, five times per week for a period of 16 weeks and the control group without any scheduled treatment. Data were gathered for 16 weeks (May 21, 2007- September 10, 2007) and were analyzed by using SPSS Win 12.0. Results: The pain, stiffness, ADL, balance and bone mineral density in the exercise group were improved significantly after the Resistance Exercise Program. However, a significant improvement on the above mentioned variables was not observed in the control group.

• Transactions of the KSME C: Technology and Education
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• v.2 no.1
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• pp.9-13
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• 2014

Nowadays, among several reasons for customers to choose their own cars, NVH performance plays much important role. The concern for the car interior noise is increasing recently, because electric cars and hybrid cars generate less engine noise which was the main noise of traditional cars. According to oversea references, high Lateral Dynamic Stiffness (LDS) of vehicle wheels is described to reduce Structure Bone Noise (SBN) which is being generated while driving cars. However availablet test standards and test results are not enough, in this study the interior noise has been measured after attaching a same tyre to several wheels which has different Lateral Dynamic Stiffness. The test has verified that the interior noise differs depending on Lateral Dynamic Stiffness of wheels. As to this, the reduction of the interior noise can be possible with the optimal design of the wheel.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.4
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• pp.291-296
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• 2003

The use of resonance frequency analysis (RFA) provides a possibility to clinically measure implant stability and osseointegration. The implant stability quotient (ISQ) value of RFA is well known that influenced by effective abutment length and stiffness of the implant in the surrounding tissues. Among these factors stiffness is not accurately defined histologically yet. And the purpose of this study was to find the histolgical relationship of RFA. 17 implants in 3 beagle dogs were used for this study. Among these implants 10 were survived for 7 months, 4 were survived for 3 months and 3 were immediate status after placement. Resonance frequency analyses were conducted and the dogs were sacrificed. Percentage of the bone to implant contact (BIC) in the interface, percentage of the mineralized bone (bone area) within the threads of the implant, and marginal bone level were measured under light microscopy. The correlation between resonance frequency and histomorphometric measurements were analysed and following results were obtained. 1. There was statistically significant correlation between ISQ value and BIC on healed implants. But ISQ value and BIC of all implants were not significantly correlated. (P<0.01) 2. Significant correlation between ISQ value and bone area was not found in this study. 3. There was statistically significant correlation between ISQ value and marginal bone level on all implants as well as on healed implants. (P<0.01).

• International Journal of CAD/CAM
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• v.9 no.1
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• pp.121-128
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• 2010

The purpose of this study is to clarify the mechanical behavior of human lumbar vertebrae (L3/L4) with and without fusion bone under physiological axial compression. The author has developed the program code to build the patient specific three-dimensional geometric model from the computed tomography (CT) images. The developed three-dimensional model provides the necessary information to the physicians and surgeons to visually interact with the model and if needed, plan the way of surgery in advance. The processed data of the model is versatile and compatible with the commercial computer aided design (CAD), finite element analysis (FEA) software and rapid prototyping technology. The actual physical model is manufactured using rapid prototyping technique to confirm the executable competence of the processed data from the developed program code. The patient specific model of L3/L4 vertebrae is analyzed under compressive loading condition by the FEA approach. By varying the spacer position and fusion bone with and without pedicle instrumentation, simulations were carried out to find the increasing axial stiffness so as to ensure the success of fusion technique. The finding was helpful in positioning the fusion bone graft and to predict the mechanical stress and deformation of body organ indicating the critical section.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.92-95
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• 2008

Purpose: Heterotopic ossification in pressure sore patients is reported to rarely develop, but once it occurs, it frequently causes joint stiffness and mobilization restriction. The aim of this article is to report our experience of atypical bone growing at femur neck fracture site with chronic, extensive pressure sore in patient with paraplegia secondary to spinal injury. Methods: A 28-year-old male patient presented with atypical bone growth at femur neck fracture site with pressure sore. He had undergone atypical growth bone removal and separation of united iliac bone and femur, and then pressure sore was covered by advanced rotation flap. Results: The patient mobilized hip joint and rode in a wheelchair. Complications such as dehiscence, infection, hematoma and flap necrosis did not occur. Conclusion: We experienced successful correction of atypical bone growth removal and recovery of pressure sore. We report our experience of atypical bone growth of fracture site and the related literature was reviewed.