• Applied Microscopy
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• v.30 no.2
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• pp.213-232
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• 2000

The development of the knee joint was studied by electron microscopy in human fetuses ranging from 20 mm to 260 mm crown-rump length ($7\sim30$ weeks of gestational age). The appearance of the primordium of the meniscus and cruciate ligament was conspicuous as the mesenchymal cells , preceeding that of joint space at 30 mm fetus. The primitive joint cavity was first seen in the interzone from the 40 mm fetus and its intermediate layer proceeded developing as a narrow cleft which was closely incorporated with two chondrogenic layers. Poorly differentiated mesenchymal cells of the meniscus at 40 mm fetus containing predominantly free ribosomes differentiated into fibroblasts at 60 mm fetus. By 100 mm fetus, the fibroblast in inner zone of the meniscus presented as oval profiles with a short cell processes, whereas middle and peripheral zones presented as elongated cells. Differentiation of the synovial membrane coincided with clarification of the joint cavity When dilatation of the synovial cavity occurred, the two types of synovial cells were identified at 60 mm fetus. By 100 mm fetus a majority of the intimal cells were B-type. B-type cells were clearly distinguishable from A-type cells by their content of extensive rough endoplasmic reticula and well developed Golgi complexes. In contrast, A-type cells had numerous filopodia, pinocytotic vesicles, lysosomes and large vacuoles. At 260 mm fetus the B-type cells were also a majority of intimal cells. At 260 mm fetus the inner zone of the meniscus was filled with parallel oriented fascicles of collagenous fibers and oval fibroblasts. The middle zone was constituted of parallel and radially arranged fibers and fibroblasts. The outer zone was populated by elongated fibroblasts encircled by crossed collagenous fibers with the blood vessels. At 30 mm fetus the fibroblasts of the cruciate ligament contained rough endoplasmic reticula and mitochondria. Collagen fibrils were noted within narrow cytoplasmic processes which were continued with the extracellular space. Collagen fibrils of ligament were filled in the bulk of extracellular space at 100 mm fetus. By $150\sim260mm$ fetus, the cruciate ligaments were constituted of longitudinally oriented bundle of collagen fibrils with irregular rows of round cells between.

• The korean journal of orthodontics
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• v.40 no.6
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• pp.364-372
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• 2010

Objective: This study was designed to assess the diagnostic validity of digital panoramic radiographs compared to cone beam computed tomography (CBCT) in patients with temporomandibular joint disorders. Methods: Panoramic radiograph and CBCT were taken from a total of 212 joints from 106 subjects. The joints were examined by two dentists and divided into the following six groups: normal, flattening, osteophyte formation, erosion, sclerosis, and unclassified. The sensitivity and specificity of each observer and inter-observer reliability were statistically analyzed. Results: The results showed relatively high intra-observer reliability in the diagnosis of both panoramic and CBCT images and the weighted Kappa indices of panoramic and CBCT images were 0.714 and 0.727, respectively. The sensitivities of panoramic images of observer A and B to CBCT images was 82.35% and 84.30%, respectively, while the specificity of observer A and B was 58.06% and 61.54%, respectively. However, guided diagnosis from panoramic and CBCT images were statistically different (p < 0.05). Conclusions: The present study suggests that the panoramic radiograph could be used as a primary diagnostic device to detect bony changes of temporomandibular joints in clinical orthodontics, because panoramic images showed relatively high sensitivity compared to CBCT images. However, CBCT images may be one of the best choices when a more accurate diagnosis is necessary.

• Journal of the Korean Arthroscopy Society
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• v.2 no.2
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• pp.155-158
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• 1998

The purpose of this study is to evaluate the cause, size, number, nature and locaton of loose bodies in the knee joint and to describe the proper arthroscopic technique to remae the loose bodies according to the location of them. We retrospectively analysed thirty-three operations of arthroscopic removal of loose bodies from the knee. Eleven males and 22 females were included with average age of 38(range 7-71). Total number of removed loose bodies were more than sixty. The loose bodies were found most commonly at anterior intercondylar notch area. The most common associated pathology was degenerative arthritis. The most common size of loose bodies was in the range of 5mm to 10mm in diameter. The most common nature of loose bodies was osteochondral. The loose bodies located in suprapatellar pouch, medial gutter, lateral gutter. anterior intercondylar notch or posterior intercondylar notch were removed using standard portals such as anteromedial, anterolateral, superomedial and posteromedial portals. The removal of loose bodies located in upper portion of posteromedial or posterolateral compartment were greatly enhanced using posterior trans-septal portal. The proper portals for the visualization and removal of loose bodies were identified according to the location of loose bodies in the knee joint. More skill in the use of the arthroscope is required for the removal of loose bodies than for simple diagnostic arthroscopy.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.253-267
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• 2008

The purpose of this study was to evaluate the pattern and the magnitude of stress distribution in the supporting tissues surrounding implant fixture with different diameter of implant fixtures(3i implant, Ø4.0, Ø5.0, Ø6.0mm and UCLA abutments(Ø4.1, Ø5.0, Ø6.0mm using photoelastic stress analysis. Photoelastic model was made with PL-2 resin(Measurements Group, Raleigh, USA) and three implants of each diameter were placed in the mandibular posterior edentulous area distal to the canine. Individual crowns were fabricated using UCLA abutments. Photoelastic stress analysis was carried out to measure the fringe order around the implant supporting structure under simulated loading conditions(15 lb, 30 lb). The results were as follows; 1. The more the diameter of implant fixture was increased, the less the stress concentration on cervical area of fixture was observed under loading. 2. Increasing mesiodistal diameter of implant superstructure had no much influence on stress distribution around implant fixture. 3. The use of smaller abutment had no influence on stress distribution around implant fixture. The use of smaller abutment diameter than that of implant fixture had no favorable effect on implant supporting tissue at biomechanical consideration.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.185-197
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• 2006

The aim of this study was to investigate the beneficial effect of a daily dose of 300 mg of ASU taken for more than 3 months on the subjects diagnosed as osteoarthritis of temporomandibular joint by RDC/TMD. Total 68 outpatients(15-54y) of female except menopause in Orofacial Pain Clinics of the Pusan National University Hospital were randomly assigned to either an ASU group(n=36) or a placebo group(n=32). The pain, noise and limited mouth opening(LOM) were evaluated by numerical analogue scale(NAS, range 0-10) and maximum comfortable opening(MCO) were measured by milimeter scale. The difference of simple uptake rate(SUR) on bone scan, hot spot(HS) on coronal SPECT, condylar bony changes on CT between the ASU and placebo groups were compared to investigate the objective effect. The obtained results were as follows. 1. Comparison of the NAS of pain, noise, LOM and MCO before treatment and 3, 6 and 9 months after treatment showed no significant difference between the ASU and placebo groups. 2. Comparison of the NAS of pain, noise, LOM and MCO before treatment and 3, 6 and 9 months after treatment showed no significant difference between the ASU and placebo groups without splint treatment, but showed more increased MCO in the ASU group than the placebo group with splint treatment at 6, 9 months after treatment. 3. Comparison of the NAS of pain before treatment and 3, 6 and 9 months after treatment that the NAS of pain at first visit divided into two groups(above or below 6) showed more decreased the NAS of pain in the ASU group than the placebo group that the NAS of pain at first visit was above 6. 4. Comparison of the NAS of pain, noise, LOM and MCO during 6 months period showed improvement of clinical symptoms within group, but no significant difference between subjects. 5. The simple uptake ratio(SUR) on bone scan and hot spot(HS) on coronal SPECT showed more increased SUR and HS in affected side than non-affected side of the ASU and placebo groups. 6. Comparing of condylar bony changes, osseous remodeling were observed highest, osteophyte lowest in the affected and non-affected side of the two groups. After treatment, comparison of condylar bony changes were observed more decreased erosive features in the ASU group than the placebo group.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.361-367
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• 2015

This paper presents the design concept of an intrinsic continuum robot for safe man-machine interface and characteristic behaviors of its end-effector based on real experiments. Since pneumatic artificial muscles having similar antagonistic actuation to human muscles are used for main backbones of the proposed robot as well as in the role of the actuating devices, variable stiffness of robotic joints can be available in the actual environment. In order to solve the inherent shortcoming of an intrinsic continuum robot due to bending motion of the backbone materials, a Kalman filter scheme based on a triaxial accelerometer and a triaxial gyroscope was proposed to conduct an attitude estimation of the end-effector of the robot. The experimental results verified that the proposed method was effective in estimating the attitude of the end-effector of the intrinsic continuum robot.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.283-298
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• 2008

The purpose of this study was to evaluate mechanical fit of fixture- abutment-screw interface in the internal connection implant systems. In this study, each two randomly selected internal implant fixture- abutment assemblys from Certain, Xive, Replace, Ankylos, SS II. were used. The implants were perpendicularly mounted in liquid unsaturated polyester by use of dental surveyor. Each abutment was connected to the implant with recommended torque value using a torque controller. All samples were cross-sectioned with grinder-polisher unit after embeded in liquid unsaturated polyester, and then fixture-abutment-screw interfaces of all samples by using optical microscope and scanning electron microscope were analyzed. Conclusively, although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal fixture-abutment connections which provides intimate contact with the implant walls to resist micromovement, resulting in a strong stable interface.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.1
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• pp.32-36
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• 2012

A 56 year-old female presented with dysphagia 8 weeks ago and newly developed dysphonia 2 weeks ago. The radiology study and swallowing difficulty evaluation study revealed the esophagus and the posterior wall of the laryngopharynx to be severely compressed by the mass of the anterior $4^{th}$ and $5^{th}$ vertebral body of cervical spine. En bloc excisional biopsy of the bony mass was performed, which completely resolved the clinical symptoms. We report a rare case of osteochondroma occurring at the anterior portion of cervical spine leading to dysphasia and dysphonia with a review of relevant literature.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.259-271
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• 2013

The purpose of this study was to make the stress distribution produced by simulated different load under two types of internal connection implant system (stepped and tapered type) by means of 3D finite element analysis, The finite element model was designed with the parallel placement of the one fixtures ($4.0mm{\times}11.5mm$) with reverse buttress thread on the mandibular 1st molar. Two models were loaded with 200 N magnitude in the vertical direction on the central position of the crown, the 1.5 mm and 3 mm buccal offset point from the central position of the fixture. The oblique load was applied at the angle of $30^{\circ}$ on the crown surface. Von Mises stress value was recorded and compared in the fixture-bone interface in the bucco-lingual dimension. The results were as follows; 1. The loading conditions of two internal connection implant systems (stepped and tapered type) were the main factor affecting the equivalent bone strain, followed by the type of internal connections. 2. The stepped model had more mechanical stability with the reduced max. stress compared to $11^{\circ}$ tapered models under the distributed oblique loading. 3. The more the contact of implant-abutment interface to the inner wall of implant fixture, the less stress concentration was reduced.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.615-618
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• 1998

Systemic arteriovenous(AV) fistulas are a rare but well-recognized cause of hyperkinetic circulation that, if undetected, may lead to congestive heart failure. We experienced a very rare case of acquired arteriovenous fistula. A 61-year-old female patient presented with congestive heart failure symptoms after percutaneous pinning for right sternoclavicular joint dislocation. We surgically obliterated the fistula between aorta and innominate vein and performed tricuspid annuloplasty for severe tricupid insufficiency simultaneously. She was discharged with complete relief of her symptoms and has been well during 2 years and 6 months follow up.