Optic nerve gliomas manifest either as a solitary form or a component of von Recklinghausen's neurofibromatosis. The reported incidence of coexistence with neurofibromatosis varies from 12% to 70%. Usually there are no significant cytological differences between the gliomas that accomapny the disease and those that are deemed to be solitary manifestations. The only possible difference between them is the apparently more common association, with the former, of extensive arachnoid hyperplasia and of a more florid local gliomatous infiltration into the leptomeninges, altogether resulting in perineural thickening. Our cases were 8 and 6 years old girls, respectively, presented with slowly progressive proptosis for 4 years and visual disturbance for 2.5 months. There were multiple cafe au lait spots on their trunks, and case 2 showed Lisch nodules in the iris. MRI of brain revealed unilateral optic nerve thickening with involvement of chiasm or multiple intracranial lesions. Resection of optic nerve tumor was performed. Microscopically, variable degree of tumorous change was seen. Most typically enlarged area was composed of intraneural and perineural portions surrounded by a layer of intact dura. Intraneural tumor revealed proliferation of elongated, spindle-shaped pilocytic astrocytes in intertrabecular spaces and distention of the pial septa with fibrovascular thickening. Another segment had areas with reactive gliosis. Perineural tissue was considerably thickened and, associated with proliferation of meningothelial cells and fibroblasts intermingled with astrocytes and Rosenthal fibers. There were increase of the optic nerve diameter and distention of the overlying dura. Foci of arachnoid cell hyperplasia were noted in both cases, although differed in degree. Immunohistochemically, the tumor cells expressed glial fibrillary acidic protein in intraneural and perineural portions particularly in case 2.
Incidence

Malignant hyperthermia is a dramatic syndrome that rarely arises during anesthesia and which is still fatal in the majority of cases. It is a hypermetabolic muscle condition characterized by hyperpyrexia and skeletal muscle rigidity. Any potent inhalation anesthetic agent or any skeletal muscle relaxant can trigger this acute catast rophic reaction. A case is presented of a 28 year old femal with a family history of malignant hyperthermia in herrelatives. She sunderwent repair of a retinal detachment under N2O-O2-halothane withcinduction by thiopenthal and succinylcholine. One and half hours after induction, arrhythmia developed and was followed by unstable blood pressure, hyperpyrexia, muscular rigidity. Anesthesia was ended and vigorous emergency treatment was attempted. But she died postoperatively on the 4th day after anesthesia. The etiologic factors, incidence, clinical feature, prevention, treatment and prognosis of malignant hyperthermia are discussed.
Incidence

Cervical plexus block has been evaluated clinically for surgery of the anterior neck in 13 patients during the 10 months(from July 1981 to April 1982) at the Department of Anesthesiology in Capital Armed Forces General Hospital. We have assessed CPB for technique, onset, anesthetized area, duration, complication and supplimentary agents, and reviewed the anatomical aspects of cervical plexus. The distribution of injected local anesthetics was demonstrated under radiography using Urographin. We experienced incomplete block in 9 cases which needed substitution with Thalamonal. The incidence of complications was few and most significant complication seen in this study was respiratory difficulty. However, There was no evidence for phrenic nerve paralysis. Cervical plexus block was performed safely and effectively for surgery of the anterior neck.
Incidence

History, incidence and associated anormalies of the anorectal malformations were reviewed.
Incidence

Though basal cell carcinoma is the most frequent and increasing malignant tumor of the skin in Korea, its pathological analysis has been done only on the small numbers. So, we did a comprehensive pathologic study on the 283 patients with basal cell carcinoma diagnosed in the Department of Pathology, Seoul National(233cases) and Chung-Ang(50cases) University Hospital during 1975-1992. The age distribution was ranged from 15 to 84 years with highest incidence rate in the age group of 5th-8th decades and 83.7% of all patients were over 40 years of age. Sex difference was not noted. The most common site was face occuring in 235 out of 283cases(83.0%) especially in the eyelid(25.5%), nose(17.9%) and cheek(16.6%). The most frequent histopathologic type was solid type(54.0%) followed by mixed(23.9%), adenoid(7.5%), and metatypical(4.7%). Among 51 mixed type, all showed solid components with adenoid(51.0%) followed by morphea(25.5%) and metatypical type(13.7%). And among 14 recurrent cases, solid type is found in 50% of cases. The characteristic clinicopathological findings are solid arrangement of tumor cells with various histological pattern and predominant occurence on the face.
Incidence

Multiple symmetric lipomatosis is a rare disease and affects almost exclusively middle aged man, usually with a background of excessive a alcohol intake. The disease is characterized by progressive growth of subcutaneous fat masses which are located symmetrically at neck, shoulders, chest, abdomen and groin, and which subsequently penetrate deeply into the surrounding spaces and structures with symptomatic compression of deep organs, such as trachea. A recent survey revealed a high incidence of sometic and autonomic neuropathy. The exact cause of the disease is not known, but a hyperplastic mechanism has been postulated, with in vitro studies demonstrating a defect in adrenergic-stimulated lipolysis of lipomatous tissue. We have experienced two cases of multiple symmetric lipomatosis. Case 1 was a 59-year-old male, complaining of slowly enlarging doughunt ring-shaped mass at his neck. He had a habit of excessive alcohol intake for many years. The subcutaneous mass at the neck was excised. The pathology report described the specimen as "normal adipose tissue". Case 2 was a 49-year-old male, complanining of slowly enlarging multiple symmetric masses at the neck, shoulders, chest, abdomen, flank and groin over a period of 6 years. He also complained of mild muscular weakness. He had a habit of excessive alcohol intake for many years. The subcutaneous mass in the neck was excised. The specimen had a tendency to form globular masses and microscopically indistinguishable from mature adipose tissue.
Incidence

STATEMENT OF PROBLEM: Higher incidence of prosthetic complications such as screw loosening, screw fracture has been reported for posterior single tooth implant. So, there is ongoing research regarding stability of implant-abutment interface. One of those research is increasing the implant diameter and prosthetic table width to improve joint stability. In another part of this research, internal conical type implant-abutment interface was developed and reported joint strength is higher than traditional external hex interface. Purpose. The purpose of this study is to compare stress distribution in single molar implant between external hex butt joint implant and internal conical joint implant when increasing the implant diameter and prosthetic table width : 4mm diameter, 5mm diameter, 5mm diameter/6mm prosthetic table width. MATERIAL AND METHOD: Non-linear finite element models were created and the 3-dimensional finite element analysis was performed to see the distribution of stress when 300N static loading was applied to model at 0., 15., 30.off-axis angle. RESULTS: The following results were obtained: 1. Internal conical joint showed lower tensile stress value than that of external hex butt joint. 2. When off-axis loading was applied, internal conical joint showed more effective stress distribution than external hex butt joint. 3. External hex butt joint showed lower tensile stress value when the implant diameter was increased. 4. Internal conical joint showed lower tensile stress value than external hex butt joint when the implant diameter was increased. 5. Both of these joint mechanism showed lower tensile stress value when the prosthetic table width was increased. CONCLUSION: Internal conical joint showed more effective stress distribution than external hex joint. Increasing implant diameter showed more effective stress distribution than increasing prosthetic table width.
Incidence

The incidence of glomerulonephritis associated with malignancy is not common. Membranous glomerulonephritis associated with carcinomas and minimal change nephrotic syndrome with Hodgkin's disease has been occasionally reported. The pathogenesis of glomerular injury associated with malignancy is not well known. The IgA nephropathy associated with malignancy, though rare, has been reported. IgA nephropathy associated with acute myeloid leukemia, however, is yet to be reported. We hereby report a case of IgA nephropathy associated with acute myeloid leukemia (AML M2).
Incidence

The incidence of glomerulonephritis associated with malignancy is not common. Membranous glomerulonephritis associated with carcinomas and minimal change nephrotic syndrome with Hodgkin's disease has been occasionally reported. The pathogenesis of glomerular injury associated with malignancy is not well known. The IgA nephropathy associated with malignancy, though rare, has been reported. IgA nephropathy associated with acute myeloid leukemia, however, is yet to be reported. We hereby report a case of IgA nephropathy associated with acute myeloid leukemia (AML M2).
Incidence

Author investigated safety accidents occurred in 26 companies during one year to study on the relationship between safety accident and shift systems.Safety accident incidence rate in 2-shifting system was 12.4 spells per 100 workers, was 1.7 times higher than 3-shifting system (7.3 spells) and 4 times than nonshift system (3.1 spells). The proportion of safety accident occurred by workers' mistake was 77.0 % at 3-shifting system, 68.8 % at 2-shifting system and 40.7 % at nonshift system. Safety accident incidence rate by workers' mistake in 2-shifting system was 8.5 spells per 100 workers, was 3.5 times higher than 3-shifting system (5.6 spells) and 5.3 times than nonshift system (1.6 spells). There was no fluctuation of safety accident incidence in nonshift system by time. But in 2- and 3-shifting system, spells of safety accident at the daytime were more higher than nighttime, vise versa spells of safety accident by workers' mistake. In nonshift system, a weekday of the most safety accident incidence was Thursday. But in 3-shifting system the most safety accident incidence was happened at weekend , vice versa in 2-shifting system. The proportion of admission by safety accidents was 44.6 % at 3-shifting system (33 spells) that was more higher than 2-shifting system (33.2 %) and nonshift system (22.4 %). Author concluded that safety accident incidences at shifting system were more higher than nonshift system and also more serious injuries were occurred. So the various comprehensive methods for the safety system, were needed to decrease the safety accident incidence and to increase worker's well-being.
Incidence