1.Biomechanical evaluation of dental implants with different surfaces: Removal torque and resonance frequency analysis in rabbits.
Jung Woo KOH ; Jae Ho YANG ; Jung Suk HAN ; Jai Bong LEE ; Sung Hun KIM
The Journal of Advanced Prosthodontics 2009;1(2):107-112
STATEMENT OF PROBLEM: Macroscopic and especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Dental implants with modified surfaces have shown stronger osseointegration than implants which are only turned (machined). Advanced surface modification techniques such as anodic oxidation and Ca-P application have been developed to achieve faster and stronger bonding between the host bone and the implant. PURPOSE: The purpose of this study was to investigate the effect of surface treatment of titanium dental implant on implant stability after insertion using the rabbit tibia model. MATERIAL AND METHODS: Three test groups were prepared: sandblasted, large-grit and acid-etched (SLA) implants, anodic oxidized implants, and anodized implants with Ca-P immersion. The turned implants served as control. Twenty rabbits received 80 implants in the tibia. Resonance frequencies were measured at the time of implant insertion, 2 weeks and 4 weeks of healing. Removal torque values (RTV) were measured 2 and 4 weeks after insertion. RESULTS: The implant stability quotient (ISQ) values of implants for resonance frequency analysis (RFA) increased significantly (P < .05) during 2 weeks of healing period although there were no significant differences among the test and control groups (P > .05). The test and control implants also showed significantly higher ISQ values during 4 weeks of healing period (P < .05). No significant differences, however, were found among all the groups. All the groups showed no significant differences in ISQ values between 2 and 4 weeks after implant insertion (P > .05). The SLA, anodized and Ca-P immersed implants showed higher RTVs at 2 and 4 weeks of healing than the machined one (P < .05). However, there was no significant difference among the experimental groups. CONCLUSION: The surface-modified implants appear to provide superior implant stability to the turned one. Under the limitation of this study, however, we suggest that neither anodic oxidation nor Ca-P immersion techniques have any advantage over the conventional SLA technique with respect to implant stability.
Dental Implants
;
Imidazoles
;
Immersion
;
Nitro Compounds
;
Osseointegration
;
Rabbits
;
Tibia
;
Titanium
;
Torque
2.Pathologic Finding of Thymic Carcinoma Accompanied by Myasthenia Gravis.
Se Hoon KIM ; Im Suk KOH ; Yang Ki MINN
Journal of Clinical Neurology 2015;11(4):372-375
BACKGROUND AND PURPOSE: The World Health Organization (WHO) has classified thymic carcinoma and other thymomas (types A, AB, and B) as different neoplasms. Myasthenia gravis (MG) is an early sign of thymoma and theoretically does not accompany thymic carcinoma; however, cases of thymic carcinoma with MG have been reported. Whether thymic carcinoma can accompany MG has yet to be established. METHODS: The medical records of patients who underwent thymectomy for MG between 1990 and 2011 in a single hospital were reviewed. All cases with the diagnostic code of "thymic carcinoma" or "thymoma type C" (old terminology) were selected. A pathologist re-reviewed the pathologic specimens using the new WHO criteria. The rate of thymic carcinoma among these MG patients was then calculated. RESULTS: A total of 81 patients with MG had thymic tumors, 10 of whom had thymic carcinomas or thymoma type C. Seven cases of well-differentiated thymic carcinomas (type B3) were excluded, leaving three (3.7%) cases of thymic carcinoma with MG. All three of these cases were type B3 thymoma with a focal squamous cell carcinoma component that was very small and well demarcated. In addition, two out of the three tumors were found to be at an early clinical stage. All of the cases survived without recurrence over follow-up periods of at least 5 years. CONCLUSIONS: Thymic carcinoma transformation from thymoma can occur during the early stages of thymoma. The association of this condition with MG is not as rare as was previously thought. Thymic carcinomas accompanying MG had a predominant B3 thymoma component with a focal thymic carcinoma area (squamous cell carcinoma).
Carcinoma, Squamous Cell
;
Follow-Up Studies
;
Humans
;
Medical Records
;
Myasthenia Gravis*
;
Recurrence
;
Thymectomy
;
Thymoma*
;
Thymus Neoplasms
;
World Health Organization
3.THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS OF STRESS DISTRIBUTION IN ALL-CERAMIC CROWNS WITH VARIOUS FINISH LINE DESIGNS AND INCISAL REDUCTIONS UNDER DIFFERENT LOADING CONDITIONS.
Eun Suk KOH ; Sun Hyang LEE ; Jae Ho YANG ; Hun Young CHUNG
The Journal of Korean Academy of Prosthodontics 1997;35(4):742-766
The purpose of this study was to determine the effect of finish line design, amount of incisal reduction, and loading condition on the stress distribution in anterior all-ceramic crowns. Three-dimensional finite element models of an incisor all-ceramic crown with 3 different finish line designs : 1) shoulder with sharp line angle 2) shoulder with rounder line angle 3) chamfer : and 2 different incisal reductions : 2mm and 4mm were developed. 300 N force with the direction of 45 degree to the long axis of the tooth was applied at 3 different positions : A) incisal 1/3, B) incisal edge, C) cervical 1/5. Stresses developed in ceramic and cement were analyzed using three-dimensional finite element method. The results were as follows : 1. Stresses were concentrated in the margin region, which were primarily compressive in the labil and tensile in the lingual. 2. Stresses were larger in the area near line angle than on the crown surface of the margin region. In case of shoulder with sharp line angle, stresses were highly concentrated in the porcelain near line angle. 3. At the interface between porcelain and cement and at the porcelain above the margin on crown surface, stresses were the highest in chamfer, and decreased in shoulder with sharp line angle and shoulder with rounded line angle, respectively. 4. At the interface between cement and abutment on crown surface, stresses were the highest in shoulder with sharp line angle, and decreased in shoulder with rounded line angle and chamfer, respectively. 5. The amount of incisal reduction had little influence on the stress distribution in all-ceramic crowns. 6. When load was applied at the incisal edge, higher stresses were developed in the margin region and the incisal edge than under the other loading conditions. 7. When load was applied at the cervical 1/5, stresses were very low as a whole.
Axis, Cervical Vertebra
;
Ceramics
;
Crowns*
;
Dental Porcelain
;
Finite Element Analysis*
;
Incisor
;
Shoulder
;
Tooth
4.A case report of cerebral sparganosis associated with seizure.
Kyung Sik KOH ; Tae Yul CHOI ; Ik YANG ; Woo Suk CHOI ; Sun Yung SHIN ; Hwan Jo SUH
Korean Journal of Infectious Diseases 1993;25(4):393-398
No abstract available.
Seizures*
;
Sparganosis*
5.A case of small intestinal obstruction due to phytobezoar, revealed after operation in elderly.
Jong Dae BONG ; Sang Hyuk KWAK ; Tae Woong LEE ; Hyun Seung YANG ; Hong Suk RHU ; Kang Suk KOH
Korean Journal of Medicine 2005;69(5):536-540
The major causes of small bowel obstruction are postoperative adhesion, hernia, intussusception and malignancies. However, in cases of uncommon causes of small bowel obstruction, surgeons are in a dilemma because the preoperative diagnosis and making a decision to operate are frequently difficult and delayed. Phytobezoars are unusual cause of small bowel obstruction. They are mostly due to ingestion of stringent immature fruits following gastric surgery. They are usually formed in stomach and do not migrate to the other intestinal tract, but can lead to the serious complication of acute small bowel obstruction. We are reporting a case of acute small bowel obstruction due to phytobezoar about 2x2x3 cm3 size in a 90 year old female.
Aged*
;
Aged, 80 and over
;
Bezoars
;
Diagnosis
;
Eating
;
Female
;
Fruit
;
Hernia
;
Humans
;
Intestinal Obstruction*
;
Intussusception
;
Stomach
6.Herpes simplex virus and varicella zoster virus infection in renal transplant recipients.
Sun Ae YOON ; Soo Hun PARK ; Chul Woo YANG ; Suk Ju AHN ; Young Suk YOON ; Byung Kee BANG ; Young Bok KOH
The Journal of the Korean Society for Transplantation 1991;5(1):83-89
No abstract available.
Chickenpox*
;
Herpes Simplex*
;
Herpesvirus 3, Human*
;
Simplexvirus*
;
Transplantation*
7.Herpes simplex virus and varicella zoster virus infection in renal transplant recipients.
Sun Ae YOON ; Soo Hun PARK ; Chul Woo YANG ; Suk Ju AHN ; Young Suk YOON ; Byung Kee BANG ; Young Bok KOH
The Journal of the Korean Society for Transplantation 1991;5(1):83-89
No abstract available.
Chickenpox*
;
Herpes Simplex*
;
Herpesvirus 3, Human*
;
Simplexvirus*
;
Transplantation*
8.A Choroidal Schwannoma Confirmed by Surgical Excision.
Young Jae CHO ; Jung Bin WON ; Suk Ho BYEON ; Woo Ik YANG ; Hyoung Jun KOH ; Oh Woong KWON ; Sung Chul LEE
Korean Journal of Ophthalmology 2009;23(1):49-52
Schwannomas rarely present as intraocular tumors and are often misdiagnosed as malignant melanoma. We describe a choroidal schwannoma confirmed by sclerouvectomy. A 30-year-old woman presented with a large nonpigmented intraocular mass of the choroid in the right eye and underwent surgical excision by sclerouvectomy. Histologically, the tumor was composed of a mixture of cellular solid components (Antoni A) and loose myxoid components (Antoni B). The tumor was eventually diagnosed as a schwannoma. Currently available ancillary studies are still of little value in definitively differentiating schwannomas from other choroidal tumors. In the case of atypical findings for a malignant melanoma, a benign neoplasm should be included in the differential diagnosis. This patient avoided enucleation by first having the mass excised. We are unaware of previous reports in which a choroidal schwannoma was diagnosed by surgical excision.
Adult
;
Choroid/*pathology
;
Choroid Neoplasms/*diagnosis/surgery
;
Diagnosis, Differential
;
Eye Enucleation/*methods
;
Female
;
Humans
;
Magnetic Resonance Imaging
;
Neurilemmoma/*diagnosis/surgery
9.Early diagnosis of pneumocystis carinii pneumonia by calcofluor white stain in bronchoalveolar lavage fluid.
Jae Hoon SONG ; Jung Eun CHOI ; Yong Sun JOO ; Yoon Suk KOH ; Yang Soo KIM ; Bin YOO ; Yung Joo CHO ; Won Dong KIM ; Yoo Kyum KIM
Korean Journal of Infectious Diseases 1993;25(2):125-130
No abstract available.
Bronchoalveolar Lavage Fluid*
;
Bronchoalveolar Lavage*
;
Early Diagnosis*
;
Pneumocystis carinii*
;
Pneumocystis*
;
Pneumonia, Pneumocystis*
10.Reference Range of Values of Peritoneal Equilibration Test and Changes in Peritoneal Kinetics in Korean Long-Term CAPD Patients.
Joo Hyun PARK ; Seung Hyun KOH ; Byung Soo KIM ; Chul Woo YANG ; Yong Soo KIM ; Suk Young KIM ; Euy Jin CHOI ; Yoon Sik CHANG ; Byung Kee BANG
Korean Journal of Nephrology 1998;17(6):945-951
PURPOSE: The aim of this study was to define the reference range of the peritoneal solute transfer in Korean CAPD patients and to investigate the change in peritoneal kinetics in long-term patients. METHODS: Routine PET was done 14 days after catheter break-in in 102 new CAPD patients and using our reference range of PET, the patients were categorized into 4 groups as described by Twardow- ski. In 35 long-term (>3 yrs) CAPD patients, D/Pcr, D/D0 glucose and drain volume in last follow- up (mean duration, 60+/-23 months) PET were compared with those in initial PET. RESULTS: Dialysate to Plasma creatinine ratio (D/ Pcr) at 0 hour, 2 hours and 4 hours was 0.045+/-0.062, 0.408+/-0.151 and 0.612+/-0.154, respectively. D/D0 glucose at 2 hours and 4 hours was 0.594+/-0.129 and 0.398+/-0.121, respectively. Peritoneal solute transfer rate in Korean patients was slightly lower than previously reported results in North American patients (P=0.08). Mean drain volume was 2360+/-270ml and mean residual volume was 436+/-178ml. Drain volume was well correlated with D/D0 glucose (positively, r=0.375, P<0.01) and D/Pcr (negatively, r=-0.345, P<0.01). There were no difference in peritoneal solute transfer, drain volume and residual volume according to sex, age, body surface area and diabetes. In initially high and high average trans- porters, solute transfer rate decreased significantly in followup PET. Out of 7 initially high transporters, 3 remained in high and 4 became high average transporters. Out of 12 initially high average transporters, 3 became low average transporters. Out of 8 initially low average transporters, 2 became high average transporters. And out of 8 initially low transporters, 2 became high average and 1 became high transporters. The number of episodes of perito- nitis do not significantly correlated with the changes of peritoneal solute transport rate. CONCLUSION: These data suggest that peritoneal solute transfer rate in Korean patients is slighthly lower compared with that in North American patients and in long-term CAPD patients the peri- toneal solute transport rate changed to centropetal directions (towards to mean) according to initial PET result.
Body Surface Area
;
Catheters
;
Creatinine
;
Follow-Up Studies
;
Glucose
;
Humans
;
Kinetics*
;
Peritoneal Dialysis, Continuous Ambulatory*
;
Peritonitis
;
Plasma
;
Reference Values*
;
Residual Volume