1.Three-dimensional finite element analysis of stress distribution and preload of different connection types implant with initial clamping.
Bum Hyun LEE ; Heoung Jae CHUN ; Soo Hong LEE ; Chong Hyun HAN
The Journal of Korean Academy of Prosthodontics 2006;44(2):197-206
STATEMENT OF PROBLEM: One of common problems associated with single teeth dental implant prosthetic is the loosening of screws that retain the implants. PURPOSE: The maintenance of screw joint stability is considered a function of the preload achieved in the screw when the suggested initial tightening torque is applied. The purpose of this study was to investigate acquired preload after initial clamping torque for estimating screw joint stability. MATERIAL AND METHODS: A comparative study on the effect of initial clamping of two types of implant systems with different connections was conducted. Three dimensional non-linear finite element analysis is adopted to compare the characteristics of screw preloads and stress distributions between two different types of implant systems composed with abutment, screw, and fixture under the same loading and boundary conditions. RESULTS: 1. When the initial clamping torque of 32Ncm was applied to the implant systems, all types of implants generated the maximum effective stress at the first helix region of screw. 2. Morse taper connection types of implants generate lower stress distributions compared to those by butt joint connection types of implants due to large contact surface between abutment and fixture. 3. The internal types of implant systems with friction grip type implant systems have higher resistance to screw loosening than that of the external types of implant systems since the internal types of implant systems generated larger preload than that generated by the external types for the same tightening moments.
Constriction*
;
Dental Implants
;
Finite Element Analysis*
;
Friction
;
Hand Strength
;
Joints
;
Tooth
;
Torque
2.Atlantoaxial Subluxation Caused by Spinal Manipulation: A case report.
Choong Hyun PARK ; Dong Jin CHUN ; Sung Jae LEE ; Bum Sun KWON ; Seung Cheol KIM
Journal of the Korean Academy of Rehabilitation Medicine 2001;25(4):720-723
A 29 years old woman had suffered from posterior neck and right shoulder pain for one year. She was given a spinal manipulation that was by a non-licentiate at a non-hospital. Posterior neck and shoulder pains were worsened and headache was developed after the spinal manipulation. She was recommended to be kept on the manipulation. Although physical finding was non-specific, radiologic findings of CT and MRI revealed atlantoaxial subluxation. After cervical immobilization and anti-inflammatory drug medication for three months, she recovered and did return to her work. We expect that atlantoaxial subluxation after spinal manipulation is not rare even in healthy young person without underlying pathology and can progress to serious complications unless detailed examination and management are undertaken.
Adult
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Female
;
Headache
;
Humans
;
Immobilization
;
Magnetic Resonance Imaging
;
Manipulation, Spinal*
;
Neck
;
Pathology
;
Shoulder Pain
3.Relation between Symptom Duration and Abnormal Spontaneous Activity in S1 Radiculopathy.
Bum Sun KWON ; Seong Jae LEE ; Chung Hyun PARK ; Dong Jin CHUN
Journal of the Korean Academy of Rehabilitation Medicine 2001;25(4):609-614
OBJECTIVE: It is a widely accepted belief that paraspinal muscles tend to show spontaneous activity on needle electromyography early on in a radiculopathy and distal muscles become abnormal later on. But most studies have shown the limitations of using symptom duration when interpreting electrodiagnostic findings in radiculopathy. The purpose of this study was to determine the relationship between symptom duration and abnormal spontaneous activity in S1 radiculopathy confined to abnormal H-reflex. METHOD: A retrospective study that collected the informations on symptom duration and spontaneous activity in paraspinal muscle and gastrocnemius for 112 patients with S1 radiculopathy diagnosed by unilateral H-reflex abnormality was undertaken. RESULTS: Abnormal spontaneous activity in paraspinal muscle had shown a significant negative correlation with symptom duration, that is a tendency to decrease its expression over symptom duration. On the contrary abnormal spontaneous activity in gastrocnemius muscle was rare at first a few weeks and became to show after 7 weeks. Patients with symptom duration over 1 year had higher incidence of having no abnormal spontaneous activities both in paraspinal and gastrocnemius muscle. CONCLUSION: These results suggested that symptom duration had a potential role in the diagnosis of S1 radiculopathy when H-reflex were abnormal unilaterally.
Diagnosis
;
Electromyography
;
H-Reflex
;
Humans
;
Incidence
;
Muscle, Skeletal
;
Muscles
;
Needles
;
Paraspinal Muscles
;
Radiculopathy*
;
Retrospective Studies
4.Protective Effect of Heat Shock Protein 70 Against Oxidative Stresses in Human Corneal Fibroblasts.
Yun Sang KIM ; Jung Ah HAN ; Tae Bum CHEONG ; Jae Chun RYU ; Jae Chan KIM
Journal of Korean Medical Science 2004;19(4):591-597
We evaluated DNA protection effect of heat shock protein (HSP) against cytotoxic effects of exogenous nitric oxide (NO) and reactive oxygen intermediate (ROI). Cultured human corneal fibroblasts were divided into 4 groups. Control (Group I) was not exposed to a sub-lethal heat treatment. Other 3 groups were exposed to 43 degrees C for 1 hr, then incubated at 37 degrees C during different duration (1, 6, 24 hr, Group II, III, IV, respectively). Expression pattern of HSP 70 was analyzed by Western blot. Cell viability was measured by MTT assay and the relationship between HSP 70 expression and DNA damage was examined by terminal deoxyribonucleotidyl transferase mediated dUTP-digoxigenin nick and labeling (TUNEL) stain and single cell gel electrophoresis. Expression pattern of HSP 70 was dependent on recovery times. Cell viability following heat treatment was significantly increased and the TUNEL positive cell number was decreased at 6 hr. In single cell gel electrophoresis, tail moments were increased in a dose-dependent manner by SNAP and X/XO. Following heat treatment, tail moments showed decreased significantly at 6 hr. These results suggest that induction of HSP 70 by sub-lethal heat treatment is closely related with cytoprotective effects against oxidative stresses in human corneal fibroblasts.
Cell Survival
;
Cells, Cultured
;
Cornea/*cytology
;
DNA Damage
;
Dose-Response Relationship, Drug
;
Fibroblasts/cytology/drug effects/*metabolism
;
Heat
;
Heat-Shock Proteins 70/genetics/*metabolism
;
Humans
;
In Situ Nick-End Labeling
;
Nitric Oxide/metabolism
;
Nitric Oxide Donors/pharmacology
;
*Oxidative Stress
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Reactive Oxygen Species/metabolism
;
Research Support, Non-U.S. Gov't
;
S-Nitroso-N-Acetylpenicillamine/pharmacology
;
Xanthine/pharmacology
;
Xanthine Oxidase/pharmacology
5.Apoptotic Cells and the Histopathologic Findings in Rotator Cuff Tears.
Ji Hoon SUH ; Soo Heon HONG ; Jae Bum PARK ; Jong Min KIM ; Jae Myeung CHUN
The Journal of the Korean Orthopaedic Association 2009;44(4):401-407
PURPOSE: We analyzed the relationship between the size of the torn rotator cuff and the frequency of finding apoptotic cells (apoptotic index) or pathological degeneration in the rotator cuff. MATERIALS AND METHODS: The edges of torn supraspinatus tendons were obtained from patients with rotator cuff tear (n=63). The study group consisted of 2 small, 22 medium, 22 large and 17 massive tears. For the histopathologic evaluation, the H&E stained sections of the torn supraspinatus tendons were examined. Apoptosis was detected with TUNEL assay. We analyzed the relationships between the tear size and the pathologic findings or the apoptotic index. RESULTS: Significant differences could not be found for the fibroblast cellularity, thickening of the synovial lining and proliferation of blood vessels according to the size of the rotator cuff tear. All the specimens had apoptotic cells that were concentrated around the margin of the tear site. The apoptotic indexes according to the tear size were 58.50 for the small tears, 27.25 for the medium tears, 33.29 for the large tears and 31.96 for the massive tears. No significant correlation was found between the tear size and the apoptotic index. CONCLUSION: There were no significant differences in the apoptotic indices, the fibroblast cellularity, the thickening of the synovial lining and the proliferation of blood vessels according to the size of the rotator cuff tear, and there were no correlations between the apoptotic index and the histopathologic findings.
Apoptosis
;
Blood Vessels
;
Fibroblasts
;
Humans
;
In Situ Nick-End Labeling
;
Rotator Cuff
;
Tendons
6.Follow-up Results in Patient with the Progressive Fatty Degeneration of the Rotator Cuff.
Jae Bum PARK ; Hong Jun JUNG ; Tae Soo AHN ; Jae Myeung CHUN
The Journal of the Korean Orthopaedic Association 2011;46(1):28-34
PURPOSE: To evaluate the influence of progressive fatty degeneration of the rotator cuff (shown on MRI after rotator cuff repair) on the clinical outcome. MATERIALS AND METHODS: At one-year postoperatively, 25 patients with progressive fatty degeneration on MRI were evaluated using the American Shoulder and Elbow Surgeon Standardized Assessment Form (ASES) score and the Constant score. RESULTS: Average ASES scores were 57.76+/-17.0 preoperatively, and had significantly increased to 84.8+/-11.9 at 1-year postoperatively, and to 92.7+/-7.7 at final follow up. Average Constant scores were 56.2+/-2 preoperatively, and had increased significantly to 78.2+/-11.7 at 1-year after surgery, and to 83.1+/-7.9 at final follow-up. All cases except 1 showed satisfactory results. Groups that showed re-tears, large tears or fatty degeneration on infraspinatus showed inferior results to those without these developments. CONCLUSION: On average 37.4 months of follow-up, clinical outcomes had improved in 96% of patients with progressive fatty degeneration of the rotator cuff. Therefore, progressive fatty degeneration on MRI at 1 year after rotator cuff repair does not influence final clinical results.
Elbow
;
Follow-Up Studies
;
Humans
;
Rotator Cuff
;
Shoulder
7.A Case of Benign Fibrous Histiocytoma of Nasal Dorsum.
In Ji CHO ; Bum Soo CHUN ; Sung Jae HEO ; Jung Soo KIM
Journal of Rhinology 2010;17(2):141-143
Fibrous histiocytoma usually develops indiscriminately in skin and any soft tissues of the body. To date, tumors occurring in soft tissues of the head and neck, especially around the nose, have been rarely reported. In most cases, benign fibrous histiocytoma develops as a painless mass lesion and most commonly originates in sun-exposed skin, extremities, and orbital tissue. Recently, we experienced a case of benign fibrous histiocytoma in the nasal dorsum in a 36-year-old woman who complained of a mass in the nasal dorsum. To the best of our knowledge, this is the first reported case of benign fibrous histiocytoma originating in the nasal dorsum in a Korean.
Adult
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Extremities
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Female
;
Head
;
Histiocytoma, Benign Fibrous
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Humans
;
Neck
;
Nose
;
Orbit
;
Skin
8.MR Imaging of Gestational Trophoblastic Tumors.
Hak Hee KIM ; Jae Hee LEE ; Ha Hun SONG ; Eun Ja LEE ; Taek Geun KIM ; Jin Bum PARK ; Hyun Kwon HA ; Sang Chun RO ; Mi Kyung JEE ; Jae Geun CHUNG
Journal of the Korean Radiological Society 1994;31(3):529-534
PURPOSE: To evaluate the MR findings of gestational trophoblastic tumor(GTT) in correlation with pathological results. MATERIALS AND METHODS: Nine patients who confirmed the diagnosis (four choriocarcinomas and five invasive moles) constituted the basis of our study. Pathologic specimens were taken from the tumors corresponding to the regions of interest on MR images. The MR images were analyzed in respect of the morphology and signal intensity of the tumors, uterine and adnexal vascularity, and the adnexal lesion. RESULTS: The MR findings of four choriocarcinomas were well-defined, hemorrhagic masses with central necrosis;the masses were hyperintense on Tl-weighted images. In contrast, the five invasive moles showed irregular and permeative masses with densely enhanced solid components and tiny cystic lesions. The trophoblastic proliferation, coagulation necrosis, and molar villi had variable signal intensities on Tl-and T2-weighted images. CONCLUSION: Our results suggest that MR imaging is a promising tool for noninvasive morphologic analysis of GTTS.
Choriocarcinoma
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Diagnosis
;
Female
;
Humans
;
Hydatidiform Mole, Invasive
;
Magnetic Resonance Imaging*
;
Molar
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Necrosis
;
Pregnancy
;
Trophoblastic Neoplasms*
;
Trophoblasts*
9.A case of myxedema coma treated with a large oral dose of levothyroxine.
Jung Min AHN ; Jae Hyon CHUN ; Ji Won KWON ; Sam Gyu PARK ; Hyung Bum KOH ; Jae Gwon KIM
Korean Journal of Medicine 2009;76(Suppl 1):S127-S130
Myxedema coma is the most extreme form of hypothyroidism and manifests as central nervous system dysfunction, defective thermoregulation, and cardiopulmonary decompensation. The curative treatment is based on the administration of thyroid hormones, but the dose and route of administration remain controversial. Here, we report a case of myxedema coma that was treated successfully with a large oral dose of levothyroxine
Body Temperature Regulation
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Central Nervous System
;
Coma
;
Hypothyroidism
;
Myxedema
;
Thyroid Hormones
;
Thyroxine
10.Hemiarthroplasty for Distal Humerus Fracture: A Systematic Review and Meta-analysis for Functional Outcome
Jae Man KWAK ; Erica KHOLINNE ; Yucheng SUN ; Gwan Bum LEE ; Kyoung Hwan KOH ; Jae Myeung CHUN ; In Ho JEON
Clinics in Shoulder and Elbow 2018;21(3):120-126
BACKGROUND: Treatment of distal humerus fractures in osteoporotic elderly patients is often challenging. For non-reconstructible fractures with open reduction and internal fixation, total elbow arthroplasty (TEA) is an acceptable alternative. However, the relatively high complication rates and lifelong activity restrictions make TEA less ideal for elderly or low-demand patients. Efforts to identify or develop alternate procedures that benefit relatively young, high-demand patients have resulted in increased interest in hemiarthroplasty. This systematic review reports the clinical outcomes of hemiarthroplasty for distal humeral fractures. METHODS: We systematically reviewed the databases of PubMed, Ovid MEDLINE, and Cochrane Library. All English-language studies published before June 2017 were considered for possible inclusion. Search terms included ‘distal humerus fracture’ and ‘hemiarthroplasty’. Studies reporting outcomes (and a minimum of 1 year clinical follow-up) in human subjects after hemiarthroplasty (Latitude system) for distal humeral fractures were assessed for inclusion. Patient demographics, clinical and radiographic outcomes, and complications were recorded, and homogenous outcome measures were analyzed. RESULTS: Nine studies with a total of 115 patients met the inclusion criteria. Among the included studies, the weighted mean follow-up time was 35.4 months. Furthermore, the weighted mean of the postoperative range of motion (107.6° flexion-extension, 157.5° for pronation-supination) and functional outcomes (Mayo elbow performance scores: 85.8, Disabilities of the Arm, Shoulder and Hand score: 19.6) were within the acceptable range. CONCLUSIONS: Our study indicates that hemiarthroplasty is a viable option for comminuted distal humerus fracture. Satisfactory functional outcomes were observed in most patients.
Aged
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Arm
;
Arthroplasty
;
Demography
;
Elbow
;
Follow-Up Studies
;
Hand
;
Hemiarthroplasty
;
Humans
;
Humeral Fractures
;
Humerus
;
Outcome Assessment (Health Care)
;
Range of Motion, Articular
;
Shoulder
;
Tea