1.ANALYSIS OF THE FIT IN THE IMPLANT PROSTHESIS USING LASER DISPLACEMENT METER AND THREE-DIMENSIONAL FINITE ELEMENT METHOD.
Ho Beom KWON ; Yung Soo KIM ; Chang Whe KIM
The Journal of Korean Academy of Prosthodontics 2001;39(6):611-624
A precise fit of the implant prosthesis is one of the most important factors in preventing mechanical complications. To analyze the degree of the misfit of implant prosthesis, a modal testing experiment was accomplished. And to interpret the modal testing analysis mathematically, three-dimensional finite element models were established. In the experimental modal testing analysis, with a laser displacement meter, FFT analyzer, impact hammer, etc., natural frequencies of the models with various degree of prosthesis fit were determined after the frequency response function were calculated. In the finite element analysis, the natural frequencies and mode shapes of the models which simulated those of experimental modal testing were computed. The results were as follows : 1. Natural frequencies of the prosthesis-abutment were related to the contact state between components. 2. In the modal testing experiment, the natural frequencies increased from 50micrometer to 200micrometer gap and reached a plateau. 3. In the finite element analysis, the natural frequencies decreased gradually according to the increase of the gap size. 4. In the finite element analysis, the mode shapes of model 1 with misfitting prosthesis showed different patterns from those without misfitting prosthesis. 5. The devices including a laser displacement meter used in this study were useful for measuring the natural frequencies of an implant prosthesis which had various degrees of fit.
Finite Element Analysis
;
Prostheses and Implants*
2.Morphological studies on recombinant virus(recB-8) selected by coinfection of the baculoviruses bombyx mori and autographa californica nuclear palyhedrosis viruses.
Ji Hyun] PARK ; Soo Dong WOO ; Beom Seok PKR ; Kang Sun PYU ; Jai Myung YANG ; In Shik CHUNG ; Seok Kwon KANG
Journal of the Korean Society of Virology 1993;23(1):95-104
No abstract available.
Baculoviridae*
;
Bombyx*
;
Coinfection*
3.Comparative Study between Standard and Totally Tubeless Percutaneous Nephrolithotomy.
Sung Il YUN ; Yoon Hyung LEE ; Jae Soo KIM ; Sung Ryong CHO ; Bum Soo KIM ; Joon Beom KWON
Korean Journal of Urology 2012;53(11):785-789
PURPOSE: Several recent studies have reported the benefits of tubeless percutaneous nephrolithotomy (PNL). Postoperatively, tubeless PNL patients have an indwelling ureteral stent placed, which is often associated with stent-related morbidity. We have performed totally tubeless (tubeless and stentless) PNL in which no nephrostomy tube or ureteral stent is placed postoperatively. We evaluated the safety, effectiveness, and feasibility of totally tubeless PNL. MATERIALS AND METHODS: From March 2008 to February 2012, 57 selected patients underwent standard or totally tubeless PNL. Neither a nephrostomy tube nor a ureteral stent was placed in the totally tubeless PNL group. We compared patient and stone characteristics, operation time, length of hospitalization, analgesia requirements, stone-free rate, blood loss, change in creatinine, and perioperative complications between the standard and totally tubeless PNL groups. RESULTS: There were no significant differences in preoperative patient characteristics, postoperative complications, or the stone-free rate between the two groups, but the totally tubeless PNL group showed a shorter hospitalization and a lesser analgesic requirement compared with the standard PNL group. Blood loss and change in creatinine were not significantly different between the two groups. CONCLUSIONS: Totally tubeless PNL appears to be a safe and effective alternative for the management of renal stone patients and is associated with a decrease in length of hospital stay.
Analgesia
;
Creatinine
;
Hospitalization
;
Humans
;
Kidney Calculi
;
Length of Stay
;
Nephrostomy, Percutaneous
;
Postoperative Complications
;
Stents
;
Ureter
4.Comparative Study between Standard and Totally Tubeless Percutaneous Nephrolithotomy.
Sung Il YUN ; Yoon Hyung LEE ; Jae Soo KIM ; Sung Ryong CHO ; Bum Soo KIM ; Joon Beom KWON
Korean Journal of Urology 2012;53(11):785-789
PURPOSE: Several recent studies have reported the benefits of tubeless percutaneous nephrolithotomy (PNL). Postoperatively, tubeless PNL patients have an indwelling ureteral stent placed, which is often associated with stent-related morbidity. We have performed totally tubeless (tubeless and stentless) PNL in which no nephrostomy tube or ureteral stent is placed postoperatively. We evaluated the safety, effectiveness, and feasibility of totally tubeless PNL. MATERIALS AND METHODS: From March 2008 to February 2012, 57 selected patients underwent standard or totally tubeless PNL. Neither a nephrostomy tube nor a ureteral stent was placed in the totally tubeless PNL group. We compared patient and stone characteristics, operation time, length of hospitalization, analgesia requirements, stone-free rate, blood loss, change in creatinine, and perioperative complications between the standard and totally tubeless PNL groups. RESULTS: There were no significant differences in preoperative patient characteristics, postoperative complications, or the stone-free rate between the two groups, but the totally tubeless PNL group showed a shorter hospitalization and a lesser analgesic requirement compared with the standard PNL group. Blood loss and change in creatinine were not significantly different between the two groups. CONCLUSIONS: Totally tubeless PNL appears to be a safe and effective alternative for the management of renal stone patients and is associated with a decrease in length of hospital stay.
Analgesia
;
Creatinine
;
Hospitalization
;
Humans
;
Kidney Calculi
;
Length of Stay
;
Nephrostomy, Percutaneous
;
Postoperative Complications
;
Stents
;
Ureter
5.Simultaneous chylothorax and chylous ascites.
Tae Soo JANG ; In Beom JEONG ; Do Yeun CHO ; Sung Ju KANG ; Oh Jung KWON
Yeungnam University Journal of Medicine 2017;34(2):265-269
Chylothorax or chylous ascites are rare manifestations of liver cirrhosis. We report a rare case of simultaneous chylothorax and chylous ascites in a patient with hepatitis B virus-related liver cirrhosis. A 76-year-old woman was referred to our hospital with a pleural effusion on her right side. She had no history of recent medical procedures, trauma or tumor. There was no evidence of mass or thoracic duct obstruction in a computed tomography scan. Pleural fluid and ascites were confirmed as chylothorax and chylous ascites by chemistry analysis. Despite thorough conservative care, there was no improvement. Pleurodesis was planned, but hepatic encephalopathy developed suddenly and she did not recover.
Aged
;
Ascites
;
Chemistry
;
Chylothorax*
;
Chylous Ascites*
;
Female
;
Hepatic Encephalopathy
;
Hepatitis B
;
Humans
;
Liver Cirrhosis
;
Pleural Effusion
;
Pleurodesis
;
Thoracic Duct
6.Current status of dental caries diagnosis using cone beam computed tomography.
Young Seok PARK ; Jin Soo AHN ; Ho Beom KWON ; Seung Pyo LEE
Imaging Science in Dentistry 2011;41(2):43-51
PURPOSE: The purpose of this article is to review the current status of dental caries diagnosis using cone beam computed tomography (CBCT). MATERIALS AND METHODS: An online PubMed search was performed to identify studies on caries research using CBCT. RESULTS: Despite its usefulness, there were inherent limitations in the detection of caries lesions through conventional radiograph mainly due to the two-dimensional (2D) representation of caries lesions. Several efforts were made to investigate the three-dimensional (3D) image of lesion, only to gain little popularity. Recently, CBCT was introduced and has been used for diagnosis of caries in several reports. Some of them maintained the superiority of CBCT systems, however it is still under controversies. CONCLUSION: The CBCT systems are promising, however they should not be considered as a primary choice of caries diagnosis in everyday practice yet. Further studies under more standardized condition should be performed in the near future.
Cone-Beam Computed Tomography
;
Dental Caries
7.Morphological analysis of maxillary sinus septum using computed tomography.
Jong Beom CHAE ; Sang Han LEE ; Chin Soo KIM ; Jong Bae KIM ; Tae Geon KWON
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2011;37(1):36-42
INTRODUCTION: The current study examined the morphological characteristics of maxillary sinus septum by computed tomography (CT). MATERIALS AND METHODS: Two hundred and four patients (408 maxillary sinuses) who visited dental clinic were evaluated. CT were examined. The height of the septum measured from the sinus floor to the apex of the septum more than 3 mm was defined as "sinus septum". RESULTS: The prevalence of sinus septa was 21.3% (87/408), and 31.4% (64/204) of patients had more than 1 sinus septum. Females showed higher and thinner sinus septa than males. The anatomic location of the septa were distributed in the 2nd molar region (43.7%), 1st molar region (31.0%), 2nd premolar region (21.8%) and 1st premolar region (3.5%). In 57 patients with chronic disease, there was no significant difference between sinus disease and the presence of sinus septa. The loss of remaining teeth and teeth adjacent to the sinus septum area was not related to the presence of sinus septa. Older subjects showed a reduced height and length of the septum, and a thicker septum. CONCLUSION: These results show that the maxillary sinus septum undergoes atrophy with age.
Atrophy
;
Bicuspid
;
Chronic Disease
;
Dental Clinics
;
Female
;
Floors and Floorcoverings
;
Humans
;
Male
;
Maxillary Sinus
;
Molar
;
Prevalence
;
Tooth
8.Open Reduction Through the Modified Volar Approach in Complex Dorsal Dislocations of the Metacarpophalangeal Joint.
Soo Joong CHOI ; Bong Cheol KWON ; Yong Beom LEE ; Won Hyoung SHIN
Journal of the Korean Society for Surgery of the Hand 2011;16(3):149-153
PURPOSE: To describe the surgical treatment of the complex dorsal metacarpophalangeal dislocations and its results, emphasizing on the modified volar approach with A1 pulley release. MATERIALS AND METHODS: We experienced 6 cases of dorsal dislocation of the metacarpophalangeal joint. We performed open reduction with the modified volar approach described by Eaton and Dray. Postoperatively posteroanterior and lateral radiographs of the index finger metacarpophalangeal joint and metacarpophalangeal joint range of motion was followed. RESULTS: One case with a large osteochondral fracture was operated with volar and doral approach both. Overall end results were good without any significant restriction of motion and stability of the fingers. CONCLUSION: Modified volar approach with A1 pulley release is an excellent method for complex dorsal metacarpophalangeal dislocations without osteochondral fracture.
Benzodiazepines
;
Dislocations
;
Fingers
;
Metacarpophalangeal Joint
;
Range of Motion, Articular
9.A Case of Incomplete Congenital Duodenal Diaphragm Presented as Hematemesis.
Hee Hyun YEOM ; Ki Beom KWON ; Kyung Bae PARK ; Joon Soo PARK ; Jae Ock PARK ; Young Tong KIM
Korean Journal of Pediatric Gastroenterology and Nutrition 2005;8(1):64-69
We have experienced a case of incomplete congenital duodenal diaphragm with a foreign body (a button), which was found by endoscopy in a 13 month-old girl. She had symptoms of hematemesis, vomiting and bloody stool for a day probably due to foreign body impaction.
Diaphragm*
;
Endoscopy
;
Female
;
Foreign Bodies
;
Hematemesis*
;
Humans
;
Infant
;
Vomiting
10.Early Experience with Laparoscopic Retropubic Simple Prostatectomy in Patients with Voluminous Benign Prostatic Hyperplasia (BPH).
Han Ki YUN ; Joon Beom KWON ; Sung Ryong CHO ; Jae Soo KIM
Korean Journal of Urology 2010;51(5):323-329
PURPOSE: Laparoscopic simple prostatectomy was recently developed to treat voluminous benign prostatic hyperplasia (BPH). We describe the surgical technique and assess the feasibility of laparoscopic simple prostatectomy through our early experience. MATERIALS AND METHODS: The medical records of 11 patients who underwent laparoscopic simple prostatectomy between March 2008 and January 2010 were retrospectively analyzed. The subjects were limited to the patients who satisfied the following conditions: prostate volume was at least 75 g, acute urinary retention repeatedly occurred or maximal flow rate (Qmax) was at most 10 ml/s, and International Prostate Symptom Score (IPSS) was at least 12. The surgery was performed by the laparoscopic extraperitoneal approach with a transcapsular route. Feasibility was assessed by objective operative parameters (reconversion, operating time, and blood loss) and perioperative complications. Data on short-term follow-up were also available. RESULTS: The mean age of the patients was 70.6 years. Mean preoperative prostate-specific antigen and prostate volume were 6.1 ng/ml and 109.3 cc, respectively. Mean operation time was 191.9 minutes and estimated blood loss was 390.9 cc. The resected adenoma weighed on average 72.4 g. No conversion to open surgery was required. Mean preoperative IPSS and quality of life (QoL) scores were 26.86 and 4.86. Mean Qmax, measured before the surgery, was 4.5 ml/s and residual urine was 106 ml. Mean postoperative IPSS and QoL scores were 4.2 and 1.5. After the surgery, mean Qmax was 15.5 ml/s and residual urine was 24.1 ml. CONCLUSIONS: In the case of voluminous BPH, laparoscopic retropubic simple prostatectomy is expected to be a useful treatment on the condition that the learning curve can be overcome with clinical experience.
Adenoma
;
Conversion to Open Surgery
;
Follow-Up Studies
;
Humans
;
Laparoscopy
;
Learning Curve
;
Medical Records
;
Prostate
;
Prostate-Specific Antigen
;
Prostatectomy
;
Prostatic Hyperplasia
;
Quality of Life
;
Retrospective Studies
;
Urinary Retention

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