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

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

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*

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 surgery of large cerebral arteriovenous malformation(AVM) may be complicated by the potential for serious brain swelling and hemorrhage during operation and/or postoperative period due to "normal perfusion pressure breadthrough(NPPB)". The authors present two cases of successful management of large AVM which anticipated the development of 'NPPB' using hypotension and preoperative embolization. The one case admitted with intraventricular hemorrhage and intracerebral hematoma due to rupture of large occipital AVM. We managed him with one-stage resection, followed by postoperative hypotension successfully. The another case was interesting. He had the history of intracranial hemorrhage about 13 years ago. We treated him conservatively at that time. He also had the another attack of intracranial hemorrhage in 1979. We performed angiography which revealed large AVM around trigon of left lateral ventricle. He also had another one time of intracranial hemorrhage in 1985. In 1986, We decided to treat him surgically and repeated angiography which showed enlarged AVM compare to size of AVM in previous angiogram of 1979 definitely. We embolized this lesion with Ivalon(R)(polyvinyl alcohol) and confirmed decreased size of AVM. During waiting the surgical resection, another intracranial hemorrhage occurred and recovered without surgical management. In May 1987, we decided to do operation and performed preoperative angiography, which showed reenlarged of previous embolic obliterated AVM. We resected that AVM successfully and discharged him without any aggravation of previous neurological signs. The pathologic findings of resected embolized AVM revealed infiltration of neurtrophils within vessel walls and foreign body material, surrounded by multinucleated foreign body giant cells, epitheloid cells in the vessel lumen. We reviewed the literature and discussed the enlargement of AVM, the treatment of large AVM, especially in point of view about 'NPPB' and pathologic findings of embolized AVM with Ivalon(R)(polyvinyl alcohol).
Angiography ; Brain Edema ; Foreign Bodies ; Giant Cells, Foreign-Body ; Hematoma ; Hemorrhage ; Hypotension ; Intracranial Arteriovenous Malformations* ; Intracranial Hemorrhages ; Lateral Ventricles ; Perfusion ; Postoperative Period ; Rupture

In the last decade Computed Tomography(CT) has played a critical role in the diagnostic evaluation of the patients with focal brain injury. But it is apparent from pathologic studies that CT underestimates the severity of the many forms of cerebral injury such as primary brain stem injury, non-hemorrhagic cortical contusion and diffuse axonal injury(DAI). Magnetic Resonance Imaging(MRI), however, has been shown to be highly sensitive in detecting diffuse brain injury(DBI). Among the consecutive 13 cases of DBI patients in this series for 10 months, twelve patients were verified as MR evidence of injury in prospective studies. The anatomical distribution of the injuries were 11 cases of corpus callosal lesion, 6 cases of lobar white matter lesion, 1 case of primary brain stem lesion. The sensitivities of MR imaging in detecting the primary lesion were 76.9%(10/13) in T1WI and 92.3%(12/13) in T2WI. In DBI, patients with callosal injuries had higher incidence(8/12) than lobar white matter and primary brain stem lesion, the corpus callosal atrophy by midsaggital MR imaging and behavioral seguellae in survivous of severe head injury implicate the corpus callosal injury and degeneration. More accurate detection and delineation of traumatic lesions with MR should permit more accurate prediction of neurologic and cognitive recovery and assist in optimizing form of treatment.
Atrophy ; Axons ; Brain ; Brain Injuries* ; Brain Stem ; Craniocerebral Trauma ; Humans ; Magnetic Resonance Imaging* ; Prospective Studies

Choroid plexus papilloma(CPP) is a rare intraventricular neoplasm occurring primarily in the lateral ventricle of children and the 4th ventricle of adults. The 3rd ventricle is an extremely rare site for CPP to occur. The authors report two cases of CPP of the 3rd ventricle in a 2-month-old girl and a 4-month-old boy, and one case of CPP of the 4th ventricle in a 17-year-old male. Two CPP of third ventricle were totally removed by transcortical-transventricular approach and transcallosal subchoroidal approach, respectively. The CPP in the fourth ventricle was totally removed by suboccipital approach. The subdural hygroma and hydrocephalus due to CSF overproduction was managed with subduroperitoneal shunt and ventriculoperitoneal shunt.
Adolescent ; Adult ; Cerebral Ventricle Neoplasms ; Child ; Choroid Plexus* ; Choroid* ; Female ; Fourth Ventricle* ; Humans ; Hydrocephalus ; Infant ; Lateral Ventricles ; Male ; Papilloma, Choroid Plexus* ; Subdural Effusion ; Third Ventricle ; Ventriculoperitoneal Shunt