The purpose of this study is to find the optimal reconditioning method for a debonded bracket base. In this study, metal brackets and ceramic brackets are used. There are devided into five groups by reconditioning methods (A : control(new bracket), B : heat treated, C : grinded with green stone, D : sandblasting for four seconds, E : sandblasting for eight seconds). Each reconditioned brackets were bonded and shear bond strength was measured by universal testing machine. After debonding, enamel surfaces were examined under stereoscopic microscope to determine the adhesive remnant index. The Microstructure of reconditioned bracket were examined by SEM (JSM 5200, Japan) and stereoscopic microscope (SZ-ST, Japan). 1. In metal bracket groups, sandblasting for eight seconds revealed the greatest shear bonding strength and its strength was above that of control group. 2. In ceramic bracket groups, sandblasting for eight seconds revealed the greatest shear bonding strength but its strength was below that of control group. 3. As sandblasting time was increased, shear bonding strengh of metal bracket was increased very much, but in ceramic brackets, shear bonding strength exhibited limited increase. This difference was caused by macro-mechanical retentive areas of ceramic brackets were broken for their brittle characteristics of material.
Adhesives ; Ceramics ; Dental Enamel ; Hot Temperature ; Orthodontic Brackets*

Cancer may be a disease of genes, arising from genetic damage of diverse sorts-recessive and dominant mutations, large rearrangement of DNA and gene translocation on chromosomes, all leading to distorisions of either the expression or biochemical function of genes. The search for these genetic damage in neoplastic cells now is the most important in cancer research. It has been found that the cancer relevant genes were located on the specific regions of chromosomes. To determine whether epidermal growth factor receptor(EGFR), P53 and bcr genes located in chromosomes 7, 17 and 22 are altered, we examined 12 neuroepithelial tumor with Southern blot analysis(five low grade astrocytoma, two high grade astrocytoma, two medulloblastoma, on oligodendroglioma, one ependymoma, one choroid plexus papilloma). The loss of heterozygosity(LOH) of EGFR gene was detected in two cases of medulloblastoma. The rearrangement of EGFR gene was detected in a case of ependymoma. The LOH of P53 gene was found in a case of choroid plexus papilloma and low grade astrocytoma. The rearrangement of P53 gene was founs id a case of oligodendroglioma. The LOH of bcr gene was observed in two cases of medulloblastoma and low grade astrocytoma. The rearrangement of bcr gene was observed in two cases of high grade astrocytoma. These results suggested that tumorigenesis and tumor development in the neuroepithelial tumor may invlove specific gene changes in chromosomes 7, 17 and 22.
Astrocytoma ; Blotting, Southern ; Carcinogenesis ; Choroid Plexus ; DNA ; Ependymoma ; Epidermal Growth Factor ; Genes, erbB-1 ; Genes, p53 ; Loss of Heterozygosity ; Medulloblastoma ; Neoplasms, Neuroepithelial* ; Oligodendroglioma ; Papilloma, Choroid Plexus

Five cases of chronic encapsulated intracerebral hematomas(so called "chocolate cysts") presented slowly progressive neurological deficits and hence mimicked brain tumors. The median duration of symptoms was 21 days. The first symptoms were severe headache and vomiting. At one case generalized seizure was noted. Computed tomography almost consistently demonstrated ring shaped lesions with central high density and minimal perifocal edema. Cerebral angiographic studies showed avascular mass lesions. All cases had superficial white matter lesions. Soft, well-encapsulated, organized, large intracerebral hematomas were removed surgically. Arteriovenous malformations were detected in two cases. All cases recovered completely but at one case postoperative brain swelling was noted transiently. Increasing awareness of "chocolate cyst" as a clinical and pathological entiry was necessary.
Arteriovenous Malformations ; Brain Edema ; Brain Neoplasms ; Cacao* ; Edema ; Headache ; Hematoma* ; Seizures ; Vomiting

It is well known that stereotaxic urokinase(UK) irrigation through a catheter is one of surgical methods in the management of hypertensive intracerebral hematoma(ICH) patients. Several authors recommended irrigation with 6000 IU UK, 4 times per a day. Based on authors' experience some patients who were managed with above protocol suffered from complications such as meningitis and/or pneumonia. It might be partially caused by prolonged duration of irrigation and immobilization of the patients. In order to reduce complications and to improve the final outcome of hypertensive ICH patients, we tried high dose UK irrigation(group II:irrigation with 50ml of normal saline mixed with 200,000 IU UK at immediate postoperative period, followed by two times of 20,000 IU UK irrigation per a day) to remove the ICH rapidly in those patients since Oct. 1991. We compared the rate of decreasing volume of hematoma, Glasgow coma scale(GCS) score change according to postoperative period, final outcome, and the rate of complications between this group(group II) and group I(4 times irrigation with 6,000 IU UK per a day). The results shows that the rate of decreasing volume of hematoma is slightly more rapid in group II than group I. The rate of poor outcome(vegetative and death) is lower in group II than I(group I vs. II:34% vs. 20% respectively). The rate of complication is lower in group II than I(group I vs. II:38.5% vs. 0.0%, respectively). One case(5%) of postoperative rebleeding was noted in group II. From this study, we concluded that, even if the beneficial effects are small, the high dose UK irrigation is one of protocols in the management of hypertensive ICH patients.
Catheters ; Coma ; Hematoma* ; Humans ; Immobilization ; Meningitis ; Pneumonia ; Postoperative Period ; Urokinase-Type Plasminogen Activator*

A case of an anterior communicating(Acom) artery aneurysm in a 36-year-old woman with polycystic kidney, and a case of multiple aneurysms(Acom. And anterior choroidal artery aneurysm) in a 49-year-old man with Marfan's syndrome are reported. Polycystic kidney was confirmed by abdominal ultrasonography and computed tomography. Marfan's syndrome was diagnosed with skeletal abnormalities(dolichocephaly, highly arched palate, cleft palate, arachnodactyly and tall slender height with excessive length of limbs) and marked elongation and tortuosity of the vertebral artery on cerebral angiography. Those patients were treated with the clipping of aneurysms. We will discuss the pathogenesis of cerebral aneurysm in those diseases with stress on the important points of management.
Adult ; Aneurysm ; Arachnodactyly ; Arteries ; Cerebral Angiography ; Choroid ; Cleft Palate ; Female ; Humans ; Intracranial Aneurysm* ; Marfan Syndrome* ; Middle Aged ; Palate ; Polycystic Kidney Diseases* ; Ultrasonography ; Vertebral Artery

In order to find out possible causes and measures for prevention of intracerebral hemorrhage remote from the site of cerebral aneurysm surgery, the authors analyzed five patients who developed such a complication following aneurysm surgery among 720 surgical cases of cerebral aneurysm. The aneurysm sites were posterior communicating artery(Pcom) in two cases, anterior communicating artery(Acom) in two, and Acom and middle cerebral artery(MMCA) in one. The hemorrhages in three cases occurred in the cerebellum. One in the contralateral hemisphere and one in the ipsilateral hemisphere to the operation site. All hemorrhages except one occurred vasospasm preoperatively. Fluctuation of blood pressure with sudden elevation to high level was noticed in three cases preoperatively and in all cases postoperatively. We conclude that sudden elevation of blood pressure during the remission stage of vasospasm seems to be possible cause for remote hemorrhage. To prevent this complication, we recommend meticulous control of blood pressure during surgery and in the postoperative period, especially in cases that showed fluctuation of blood pressure preoperatively.
Aneurysm* ; Blood Pressure ; Cerebellum ; Cerebral Hemorrhage ; Hemorrhage* ; Humans ; Intracranial Aneurysm ; Postoperative Hemorrhage ; Postoperative Period

The anterior interbody fusion for cervical spine disease may not provide adequate immediate stabilization, but anterior cervical spine plating has overcome this main disadvantage. Between August 1991 and August 1992, twenty patients with a variety of cervical spine abnormalities were treated by anterior cervical spine fusion with the Caspar plate system. Fourteen patients had traumatic fracture and/or dislocation, three had infection(including two tuberculous spondylitis), two had degenerative spondylosis, and on had metastatic tumor. Single level fusion was accomplished in six patients, two-level fusion in eleven patients, and three-level fusion in three patients. Among seventeen patients with an incomplete transverse lesion or neck pain, all patients showed some recovery at discharge except two patients with Frankel grade D. Complications included screw loosening(one patient), dysphagia(one patient, which subsided after removal of the plate), and transient neurological worsening(one patient). All patients had good bony fusion except one which had screw loosening. Careful attention to surgical technique is needed to assure good results.
Dislocations ; Humans ; Neck Pain ; Spine* ; Spondylosis

To evaluate the effectiveness and to find out which grade(clinical and computed tomography) of subarachnoid hemorrhage(SAH) patients are most effected with the medication of the calcium antagonist, we did this study. We selected 339 cases(study cases) among a total of 603 cases of SAH who were admitted to our hospital from Sept. 1982 to Aprial 1991. The criteria of study cases are patients who were admitted and who had a brain computed tomography(CT) taken within 3 days after the SAH and who had a clinical grade(Hung & Hess) on admission between I-IV. We divided study cases into 3 groups. Group I:surgery was done more than 7 days after the SAH and together with non-surgical patients, no medication was used(N=126). Group II:surgery was done more than 7 days after teh SAH and together with non-surgical patients medication of the calcium antagonist was given orally(N=120). Group III:surgery was done more than 7 days after the SAH and together with non-surgical patients, medication of nimodipine intravenously was given, and also patients, medication of nimodipine intravenously was given, and also patients who received surgery did within 3 days after the SAH were given intravenous injection and cisternal irrigation of nimodipine(N=93). We compared the overall management outcome and the incidence of delayed ischemic dificit(DID) and unfavorable outcome due to DID in each group. We also analyzed the causes of unfavorable outcome according to the clinical grade on admission and the amount of blood in the cistern seen on the brain CT in each group. The results of this study showed that overall management outcome was improved by using the calcium antagonist. The calcium antagonist reduced the incidence of DID as well as the unfavorable outcome related to DID. In clinical grade III patients on admission, the unfavorable outcome due to DID was significantly lower in group II and III than in I(group I vs. II:p<0.05, group I vs. III:P<0.01). In cases with a large amount of blood in the cistern seen on the brain CT, the unfavorable outcome was significantly lower in groups II and III than in I(group I vs. II:p<0.01, group I vs. III:p<0.05). We conclude that the overall management outcome of aneurismal SAH patients may be improved by using a calcium antagonist and the effect of the calcium antagonist is prominent in clinical grade III patients on admission and patients with a large amounts of blood in the cistern seen on the brain CT.
Aneurysm* ; Brain ; Calcium* ; Humans ; Incidence ; Injections, Intravenous ; Nimodipine ; Subarachnoid Hemorrhage*

In order to determine the predisposing factors to cerebral aneurysm rupture and to examine the relationship between circadian periodicity of blood pressure change and the rupture of an aneurysm, the authors investigated activities of the patients of events as well as diurnal and seasonal variations in the onset of subarachnoid hemorrhage (SAH) in 766 consecutive patients. The authors also compared the difference of these data between patients with a history of hypertension and patients without a history of hypertension. The results showed that the onset of SAH was associated with defecation and/or urination in 12.3%, working on the jab in 11.8%, housework including washing clothes in 10.3%, sleeping in 7.4% and bathing and/or washing up in 7.2%. The incidence of the onset of SAH associated with defecation an/or urination was higher in patients with a history of hypertension than in patients without a history of hypertension(p<0.05). The diurnal variation of the onset of SAH showed two broad peak times from 6 to 10 a.m.(21.8%) and from 5 to 8 p.m.(18.3%). The seasonal variation of the onset of SAH showed the incidence to be slightly higher in winter than in any other seasons autumn and winter, the leading activities of the patients or events in the onset of SAH was defecation and/or urination and, in summer, it was job performing. We concluded that the onset of the SAH is related not only to the physiological circadian periodicity of blood pressure change but also to the activities or events which induced a sharp rising blood pressure and changing the venous and cerebrospinal fluid pressure.
Aneurysm ; Baths ; Blood Pressure ; Causality* ; Cerebrospinal Fluid Pressure ; Defecation ; Housekeeping ; Humans ; Hypertension ; Incidence ; Intracranial Aneurysm* ; Periodicity ; Rupture* ; Seasons* ; Subarachnoid Hemorrhage ; Urination

Symptomatic vasospasm is still one of the major causes of death and disability in patients who suffer an aneurysmal subarachnoid hemorrhage(SAH). To identify risk factors related to symptomatic vasospasm, to determine the outcome in patients with SAH, and to determine the differences identified risk factors between patients with good and bad outcomes, we performed this retrospective study. From a total of 279 SAH patients who were admitted to our hospital between January 1993 and December 1995, 212 were chosen for study. These were patients who had been admitted within 7 days of SAH, had undergone brain computed tomography(CT) within 3 days of SAH and had survived more than 6 days after SAH. Nine variables were examined as to their relationship to symptomatic vasospasm: age, sex, admission day after SAH, hypertension history, frequency of SAH, clinical grade, CT grade, operation day after SAH, and outcome. Data were analyzed by the univariate and multivariate logistic regression method using the Statistical Analysis System(SAS). Symptomatic vasospasm was demonstrated in 30 cases(14.2%). Univariate analysis showed that admission more than 4 days after SAH(p=0.07), clinical grades III-V(p=0.001), and CT grade III(p=0.00001) were associated with a higher risk of symptomatic vasospasm. When study cases were grouped into either good or bad outcome groups, and multivariate logistic regression analysis was performed, these factors were associated with a higher risk of symptomatic vasospasm only in the good outcome group. This suggests that there is a group of patients with a predisposition to symptomatic vasospasm that is independent of these risk factors, and that in these patients, the outcome may be worse.
Aneurysm* ; Brain ; Cause of Death ; Humans ; Hypertension ; Intracranial Aneurysm ; Logistic Models ; Retrospective Studies ; Risk Factors ; Subarachnoid Hemorrhage*