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

The authors report two cases of intracranial aneurysm associated with aplasia of internal carotid artery. The one case showed complete occlusion of left internal carotid artery just above the origin of ophthalmic artery and aneurysm which located at the junction of basilar-superior cerebellar artery. The blood supply of the left side of anterior cerebral came from the right carotid artery through the anterior communicating artery and the left middle cerebral artery came from basilar artery through the enlarged posterior communicating artery. The another case showed marked narrow cervical portion of right internal carotid artery which terminated as a posterior communicating artery just above the origin of ophthalmic artery and large aneurysm which located at the anterior communicating artery. The blood supply of the right side of anterior cerebral and middle cerebral artery came from the left internal carotid artery through the anterior communicating artery. We tried to surgical management of these two aneurysms. We reviewed the literature and discussed the related collateral circulation of this anomaly.
Aneurysm ; Arteries* ; Basilar Artery ; Carotid Arteries ; Carotid Artery, Internal ; Collateral Circulation ; Intracranial Aneurysm* ; Middle Cerebral Artery ; Ophthalmic Artery

The author studied the relationship of age, Glasgow coma scale, Glasgow outcome scale and appearance of basal cisterns as seen on intial computerized tomography on 95 patients with severe diffuse head injury. The results were as follows : 1) The poor outcome rates were 76.8%, 41.2% and 16.6% among those absent, compressed, and normal basal cisterns, respectively. 2) The correlation with the initial GCS score and the status of basal cistern indicated significant difference of poor outcome rate in the patients with absent or compressed basal cisterns between GCS score 3-5 group and GCS 6-8 group while the patients with normal basal cisterns indicated significantly reduced poor outcome rate regardless of GCS score. 3) When outcome was observed in connection with the patient's age and the status of the basal cisterns, a good recovery was significantly increased in the children with normal basal cisterns while the poor outcome rate was very high in the elderly patients even if the basal cisterns were normal. Therefore, the status of the basal cisterns on CT Scan should be used as non-invasive method for predicting the outcome of severe diffuse head injured patients.
Aged ; Child ; Craniocerebral Trauma* ; Glasgow Coma Scale ; Glasgow Outcome Scale ; Head* ; Humans ; Tomography, X-Ray Computed*

A retrospective study of 100 cervical spinal cord injury patients admitted consequtively to the Department of Neurosurgery, Dongsan Medical Center, Keimyung University between March, 1985 and June, 1989 was conducted. The average age was 42 and 84(84%) were male. The majority sustained their spinal cord injury in a motor vehicle accident(50%) or in a diving accident(36%). Thirty-three percent(33/100) of these patients had surgical intervention by anterior approach(14/33), posterior approach(17/33) and total laminectomy(2/33). The others were only immobilized by traction or neck brace. Not only neurological recovery in operated and nonoperated patients but also complete and incomplete injury was compared. The degree of the neurological injury was classified by the Frankel classification. 12 cases turned out to be more aggravated than the condition at admission, among them 9 cases were middle and low cervical incomplete injuries. At final follow-up no appreciable differences in achievement in activities of daily living and mobility were noted between patients treated with surgical stabilization of the cervical spinal column and those treated nonsurgically.
Activities of Daily Living ; Braces ; Classification ; Diving ; Follow-Up Studies ; Humans ; Immobilization ; Male ; Motor Vehicles ; Neck ; Neurosurgery ; Retrospective Studies ; Spinal Cord Injuries ; Spinal Injuries* ; Spine ; Traction

We undertook a retrospective analysis of 30 patients admitted to the Department of Neurosurgery Dongsan Medical Center Keimyung University utilizing Magnetic Resonanace Imaging(MRI) to make diagnosis and surgical indication of degenerative cervical spine lesions. All patients were taken T1 Weighted Image(T1W1) T2 Weighted Image(T2WI) and gradient echo image on 2.0 Tesla unit. Pre- and postoperative MRI were obtained seven of 15 cases with myelopathy. All patients could be evaluated the extent and degree of disc herniation, osteophytes and cord compression. A focal area of High-Signal-Intensity(HIS) was observed on T2WI in 15 patients with mydlopathy predominantly. HIS diminished postoperatively in the patients who improved clinically and remained the same in one case whose condition remained unchanged after decompression. We think MRI with high resolution images in the initial procedure of choice in decision-making of patients with degenerative cervical spine lesion. Furthermore HIS of the spinal cord produced by compressive lesions appears to be an important indicator for predicting prognosis of patients with myelopathy.
Decompression ; Diagnosis ; Humans ; Magnetic Resonance Imaging ; Neurosurgery ; Osteophyte ; Prognosis ; Retrospective Studies ; Spinal Cord ; Spinal Cord Diseases ; Spine*

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*

Among 875 patients with intracranial aneurysm operated on during the past 14 years, the authors encountered eleven who had experienced recurrent hemorrhage caused by the rupture of aneurysms which had not been noticed at the time of the initial operation and the interval between initial and recurrent hemorrhage varied between 4 and 16 years. Age at the time of initial hemorrhage was relatively young(average 43.7 years). Multiple aneurysms occurred in four cases and hypertension in four others. Clinical grades at the time of the second admission were relatively poor, and in eight patients there were complications with intracerebral hematomas, intraventricular hemorrhages or acute subdural hematoma. Retrospective evaluation of the first angiograms disclosed suspicious tiny aneurysms in five cases, and these grew and ruptured at recurrent hemorrhage. In eight patients, the outcome was good; One remained moderately disabled, and two died. We conclude that the possibility of recurrent hemorrhage, after the clipping of a ruptured aneurysm, should be considered in all aneurysmal patients, especially in those who are young or have multiple aneurysms. To defermine whether or not suspicious tiny aneurysms are present in these patients, their angiograms should be subjected to detailed examination. Late postoperative follow-up angiography to determine the growth or development of another aneurysm might also be needed.
Aneurysm* ; Aneurysm, Ruptured ; Angiography ; Follow-Up Studies ; Hematoma ; Hematoma, Subdural, Acute ; Hemorrhage* ; Humans ; Hypertension ; Intracranial Aneurysm* ; Retrospective Studies ; Rupture

Clinical evaluation and imaging studies such as magnetic resonance imaging, computed tomography, and/or myelography can localize the pathologic process in most patients with lumbar radiculopathy. However, these studies occasionally fail to demonstrate exactly the cause and site for ongoing radicular symptom. So we evaluated 54 patients for the efficacy of selective nerve root blocks to identify a symptomatic nerve. The lumbar nerve root injections were performed at L3 root in 1 patients, at L4 root in 4 patients, at L5 root in 46 patients, and at S1 root in 3 patients. Among them, forty two patients were done before operation(HNP 32, stenosis 5, spondylolisthesis 5), 9 patients were done after operation due to poor results (root injury 2, infection 2, adhesion 1, incorrect diagnosis 4), and 3 patients had improved radiculopathies following nerve root injection(HNP 2, stenosis 1). The results of the nerve root injections and of the operations were not affected by age and sex. There was a good correlation between the response of the nerve root injection and the result of the operation(p<0.05). The concentration of bupivacaine 0.5% has no additional effect comparing to 0.25%(70%/73.5%) solution in spite of its adverse effect causing transient motor weakness. Additional use of depomedrol(50mg) proved to be no more beneficial. Three patients had Improved symptoms for a long period after nerve root injection which consequently made operation unnecessary. Five patients with previous history of operations had moderate pain relief. In summary, lumbar nerve root injection can be used as a functional diagnostic tool to predict operative result and as a treatment modality following failure of a previous surgery.
Bupivacaine ; Constriction, Pathologic ; Diagnosis* ; Humans ; Magnetic Resonance Imaging ; Myelography ; Radiculopathy ; Sciatica* ; Spondylolisthesis

OBJECTIVE: Until recently anterior cervical discectomy with or without bone fusion has been widely used for the treatment of cervical disc herniation. After introduction of the microsurgical anterior cervical foraminotomy(MACF), there has been a tendency to preserve the functioning motion segment. But some worried about technical difficulties and complications such as injury to the vertebral artery. This study is to compare the short-term results of anterior cervical interbody fusion(ACIF) with that of MACF. METHODS: We reviewed medical records of 40 patients, 20 patients of ACIF performed during 30 months and 20 patients of MACF performed during 8 months. RESULTS: The average length of stay in the hospital was longer in cases of ACIF(12.9 days) than in those of MACF(7.1 days). The rate of the symptom relief within 1 day was higher in MACF(90%) than in ACIF(70%). The overall satisfaction experienced by the patients after surgery was higher in MACF(85%) than in ACIF(70%). The rate of the recommendation for surgical treatment to other people was higher in MACF(85%) than in ACIF(65%). But the differences were not significant statistically. The major complication was bone donor site pain in ACIF cases and neck and shoulder pain in MACF cases. CONCLUSION: This data demonstrate that MACF is of value in the treatment of cervical disc herniation, which can be performed with safety and good outcome like conventional ACIF.
Diskectomy ; Humans ; Length of Stay ; Medical Records ; Neck ; Shoulder Pain ; Tissue Donors ; Vertebral Artery