No abstract available.
Humans* ; Ligamentum Flavum*

The radiation-induced apoptosis was studied for two human cancer cell lines (KB cells, RPMI 2650 cells) and the human gingival fibroblast cell line (HGF-1 cells). The single irradiation of 2, 10, 20Gy was done with 241.5 cGy/min dose rate using the 137Cs MK cell irradiator. The cell were stained with propidium iodide and examined under the fluoro-microscope and assayed with the flow cytometry a day after irradiation. Also, the LDH assay was done to determine the amount of necrotic cells. The obtained results were as follows : 1. On the fluoro-microscope, many fragmented nuclei were detected in the KB, RPMI 2650, and HGF-1 cells after irradiation. 2. On the DNA content histogram obtained from the flow cytometry, the percentages of the pre-G1 peak of the control and 2, 10 and 20Gy irradiation group were 4.5, 55.0, 52.3, and 66.6% on KB cells, 2.7, 3.3, 31.8, and 32.6% on RPMI 2650 cells and 2.8, 21.8, 30.4, and 40.2% on HGF-1 cells respectively. 3. The number of G1-stage cells was abruptly decreased after 2Gy irradiation on KB cells and 10Gy irradiation on RPMI 2650 cells, But there was a slight decrease without regard to irradiation dose on HGF-1 cells. 4. There was no significantly different absorbance in extracellular LDH assay along the experimental cell lines.
Apoptosis* ; Cell Line* ; DNA ; Fibroblasts* ; Flow Cytometry ; Humans* ; KB Cells ; Propidium

The purpose of this study was to investigate an influence of the change of central panoramic curves on the image reconstruction in the dental implant CT. The author designed three experimental groups according to the location of central panoramic curve. In group A, central panoramic curve was determined as the curve connecting the center of roots from the first premolar to the first molar. In group B, central panoramic curve was determined as the line connecting the lingual cortical plate at the level of the mesial aspect of the first premolar with the buccal cortical plate at the level of the mesial aspect of the first molar. In group C, central panoramic curve was determined as the line connecting the buccal cortical plate at the level of the mesial aspect of the first molar. Twenty four reformatted CT images was acquired from four mandibles embedded in the resin block and twenty four contact radiographs of dog specimens were acquired. Each image was processed under Adobe Photoshop program analysed by MSPA(mandible/maxilla shape pattern analysis) variables such as MXVD, MXHD, UHD, MHD, and LHD. The obtained results were as follows ; 1. The mean of MXVD variable was 19.9, 20.2, and 20.0 in group A, B, and C, respectively, which were smaller than actual value 20.5. But, there was no significant difference among 3 groups(p>0.05). 2. The mean of MXHD, UHD, MHD, and LHD variables in group A, B, and C was 11.9, 12.2, and 12.3; 9.3, 9.5, and 9.6; 10.0, 10.3, and 10.3; 9.2, 9.3, and 9.4 respectively which were equal to or greater than the actual value 11.8, 9.3, 10.0. But, there was no significant difference among 3 groups(p>0.05). 3. The number of noneffective observations with difference over or under 1mm with comparison to the actual value was 24(20%), 58(48.3%), and 52(43.3%), respectively, in group A, B, and C. 4. In group A, the number of observations over 1mm and under 1mm was 9 and 15, respectively, but in group B and C, the number of observations over 1mm was more than under 1mm.
Animals ; Bicuspid ; Dental Implants ; Dogs ; Image Processing, Computer-Assisted* ; Mandible ; Molar

PURPOSE: The purpose of this study was to calculate the size and CT number of both normal parotid and submandibular gland, and evaluate its relation to sex, age and obesity using computed tomography. MATERIALS AND METHODS: The computed tomography was performed parallel to the Frankfurt plane in 46 subjects with healthy salivary gland. The subjects were divided into the three groups(young, middle, old) according to their ages. The size of salivary gland was determined as maximum cross-sectional area and the CT number of salivary gland was determined as the mean CT number of three ROI's. The body mass index was calculated from weight and height. RESULTS: The mean maximum cross-sectional area was 7.79(+/-1.26) cm2 on parotid gland and 4.12(+/-0.83) cm2 on submandibular gland. The mean CT number was -4.43(+/-23.87) HU on parotid gland and 50.01(+/-15.63) HU on submandibular gland. There were decreasing pattern of the maximum cross-sectional area of submandibular gland and the CT number of both parotid and submandibular gland according to age(p<0.05). As the body mass index increased, the maximum cross-sectional area of parotid gland increased and CT number of both parotid and submandibular gland decreased(p<0.05). The maximum cross-sectional area of submandibular gland in male was larger than that in female(p<0.05). As the maximum cross-sectional area and CT number of left salivary gland increased, those of right gland increased(p<0.05). CONCLUSION: Intra-individual differences in salivary gland size and CT number is considered in the age and individual obesity.
Aging ; Body Mass Index ; Humans ; Male ; Obesity ; Parotid Gland ; Salivary Glands* ; Submandibular Gland

The purpose of this study was to evaluate cervical lymph node metastasis of oral squamous cell carcinoma patients by MRI film and neural network system. MATERIALS AND METHODS: The oral squamous cell carcinoma patients(21 patients, 59 lymph nodes) who have visited SNU hospital and been taken by MRI, were included in this study. Neck dissection operations were done and all of the cervical lymph nodes were confirmed with biopsy. In MR images, each lymph node were evaluated by using 6 MR imaging criteria(size, roundness, heterogeneity, rim enhancement, central necrosis, grouping) respectively. Positive predictive value, negative predictive value, and accuracy of each single MR imaging criteria were calculated. At neural network system, the layers of neural network system consisted of 10 input layer units, 10 hidden layer units and 1 output layer unit. 6 MR imaging criteria previously described and 4 MR imaging criteria (site I-node level 2, site II-other node level, shape I-oval, shape II-bean) were included for input layer units. The training files were made of 39 lymph nodes(24 metastatic lymph nodes, 10 non-metastatic lymph nodes) and the testing files were made of other 20 lymph nodes(10 metastatic lymph nodes, 10 non-metastatic lymph nodes). The neural network system was trained with training files and the output level (metastatic index) of testing files were acquired. Diagnosis from neural network was decided according to 4 different standard metastatic index-68, 78, 88, 98 respectively and positive predictive values, negative predictive values and accuracy of each standard metastatic index were calculated. RESULTS: In the diagnosis of using single MR imaging criteria, the rim enhancement criteria had the highest positive predictive value, 0.95 and the size criteria showed the highest at negative predictive value, 0.77. The highest accurate criteria was heterogeneity with the accuracy of 0.81 and the lowest one was central necrosis with accuracy of 0.59. In the diagnosis of using neural network systems, the highest accurate standard metastatic index was 78, and that time, the accuracy was 0.90. Neural network system was more accurate than any other single MR imaging criteria in evaluating cervical lymph node metastasis. CONCLUSION: Neural network system has been shown to be more useful than any other single MR imaging criteria. In future, Neural network system will be powerful aiding tool in evaluating cervical node metastasis.
Biopsy ; Carcinoma, Squamous Cell* ; Diagnosis ; Humans ; Lymph Nodes* ; Magnetic Resonance Imaging ; Neck Dissection ; Necrosis ; Neoplasm Metastasis* ; Population Characteristics

PURPOSE: Ionizing radiations have been reported as an apoptosis initiating stimulus in various cells and it has established that sustained elevations in [Ca2+] can lead to DNA fragmentation by Ca2+-dependent endonucleases, ultimately resulting in apoptotic cell death. The previous experiments have been reported by using primarily thymocytes and lymphocytes and the change of [Ca2+] was measured only by minutes or hours respectively. We need to evaluate [Ca2+] in both several minutes and hours after irradiation of radiation of radiation therapy and verify the apoptotic cells. MATERIALS AND METHODS: We have measured [Ca2+] in human gingival epitheloid cancer cell with 10 Gy irradiation, at minutely intervals and hourly intervals using digitized video-intensified fluorescence microscopy and the fluorescent Ca2+ indicator dye, fura-2. In order to find out that the transient rise in [Ca2+] could induced apoptosis, cells were incubated for 1 hour at 37 degrees C with TdT enzyme, rinsed and resuspended containing fluorescence and observed under a confocal fluorescence microscope. MTT assay was done to determine cell activity and LDH assay was done to determine the amount of necrotic cells. RESULTS: After irradiation, the transient and temporal increasing of [Ca2+] in the KB cells was founded. Though, there was no change in the intracellular [Ca2+] at 30 minutes and 2 hours after irradiation. We could detect of DNA fragmented cells at 4 hours after 10 Gy irradiated cells. There were no significant differences between 4 hour, 1 day, 3 day cells. There were no significant differences in MTT and LDH assay between the irradiated group and the control group after 4 hours and 1 day. Though after 3 days there were differences in MTT and LDH assay between the irradiated group was significantly decreased than the control group, in LDH assay the number of necrotic cell death of the irradiated was higher than the control group. CONCLUSION: In KB cells there were incipient and temporal increasing of the [Ca2+] with 10 Gy irradiation and the apoptosis was founded from 4 hours later which was earlier than seeing of the change of the amount of the cellular ability and necrosis.
Apoptosis* ; Cell Death ; DNA ; DNA Fragmentation ; Endonucleases ; Fluorescence ; Fura-2 ; Humans ; KB Cells* ; Lymphocytes ; Microscopy, Fluorescence ; Necrosis ; Radiation, Ionizing ; Thymocytes

The aneurysmal bone cyst is a nonmalignat reactive bone lesion. Developing rarely in the craniofacial region, and more commonly affecting the long bones and the spine, the lesion has variable etiopathogenic characteristics. The author s diagnosed a 33-year-old female as aneurysmal bone cyst after undergoning clinical, radiological and histological exami nations. The characteristics were as followed: 1. The patient complained of pain and swelling of the right preauricular area. 2. The conventional radiograms showed a relatively well difined radiolucent lesion with partially scallping margin. The cortical bone of the right condyle was thinned and expanded by the lesion. 3. Bone scintigraphy with (99m)Tc demonstrated ring-like or doughnut-pattern accumulation of radioactivity. 4. On T1-weighted imaging of MRI, the lesion on the right condyle had middle signal intensity. T2-weighted MRI demonstr ated multiple high signal intensities seperated by septa which had low signal intensity. Finger in balloon appearance wa s seen. 5. Histologically, the lesion was composed of large sinusoidal blood spaces lined by fibroblasts and histiocytes. Its fibrous stroma consisted of fibroblastic element, multinucleated giant cells, extravasated erythrocytes and focal hemosid erin pigmentation. New bone formation was also observed aroud larger sinusoidal spaces.
Adult ; Aneurysm* ; Bone Cysts* ; Erythrocytes ; Female ; Fibroblasts ; Fingers ; Giant Cells ; Histiocytes ; Humans ; Magnetic Resonance Imaging ; Mandibular Condyle* ; Osteogenesis ; Pigmentation ; Radioactivity ; Radionuclide Imaging ; Spine

The aneurysmal bone cyst is a nonmalignat reactive bone lesion. Developing rarely in the craniofacial region, and more commonly affecting the long bones and the spine, the lesion has variable etiopathogenic characteristics. The author s diagnosed a 33-year-old female as aneurysmal bone cyst after undergoning clinical, radiological and histological exami nations. The characteristics were as followed: 1. The patient complained of pain and swelling of the right preauricular area. 2. The conventional radiograms showed a relatively well difined radiolucent lesion with partially scallping margin. The cortical bone of the right condyle was thinned and expanded by the lesion. 3. Bone scintigraphy with (99m)Tc demonstrated ring-like or doughnut-pattern accumulation of radioactivity. 4. On T1-weighted imaging of MRI, the lesion on the right condyle had middle signal intensity. T2-weighted MRI demonstr ated multiple high signal intensities seperated by septa which had low signal intensity. Finger in balloon appearance wa s seen. 5. Histologically, the lesion was composed of large sinusoidal blood spaces lined by fibroblasts and histiocytes. Its fibrous stroma consisted of fibroblastic element, multinucleated giant cells, extravasated erythrocytes and focal hemosid erin pigmentation. New bone formation was also observed aroud larger sinusoidal spaces.
Adult ; Aneurysm* ; Bone Cysts* ; Erythrocytes ; Female ; Fibroblasts ; Fingers ; Giant Cells ; Histiocytes ; Humans ; Magnetic Resonance Imaging ; Mandibular Condyle* ; Osteogenesis ; Pigmentation ; Radioactivity ; Radionuclide Imaging ; Spine

The aim of this study were to measure and compare the stress level on three type brackets and each other material (stainless steel, ceramic) with tipping and torquing forces by using the finite element analysis and to design bioniechanically favorable brackets. For this study, three kinds of brackets were selected(A:Transcend-RMO, B:Signature-Unitek, C:PAW plain archwire appliance-applied for a patent in Yonsei University). The slot size of bracket was 0.022inch and the size of archwire was 0.0175x0.025inch and taper shaped archwire was used in PAW. Loading force in tipping was 4.27N and torquing force was 32.858N applied by archwire torsion with 19.7degree and 113 degree in C type bracket. The conclusions were that (1) The finite element method proved to be a useful tool in the stress analysis of orthodontic bracket subjected to various forces. (2) With tipping, the stresses were concentrated at the gingival wall of the wire slot where it meets the mesial bracket surface and the incisal wall of the wire slot where it meets the distal bracket surface and with torquing, the stresses were concentrated at the junction of the gingival or incisal wall and base of the slot. (3) The maximum stress value was higher in torquing force than tipping force and therefore it is desirable to design on the basis of torquing force. (4) It was considered that the change in material might be affect on the diminish of stress value in the place of stess concentration. (5) The maximum stress value was highest on PAW bracket when the tipping and torquing force was applied and therefore it would be desirable to use mechanically favorable material on PAW bracket.
Finite Element Analysis ; Orthodontic Brackets* ; Steel

Sinochoanal polyp is an inflammatory polyp that originates in the paranasal sinus, passes through a sinus ostium, and extends into the choana. While antrochoanal polyp is the most common type of sinochoanal polyp, sphenochoanal polyp is rare and ethmochoanal polyp is extremely more rare to find. To minimize postsurgical recurrence, it is essential to completely remove the polyp together with the base of its origin. We have recently experienced and successfully managed three cases of ethmochoanal polyp by endoscopic sinus surgery. It was difficult to histologically differentiate ethmochoanal polyp from sinonasal polyps associated with chronic rhinosinusitis. For this reason, ethmochoanal polyp should be suspected and completely removed together with the base of its origin when a large polyp originates from the ethmoid sinus and extends into the choana. Now we report three cases of ethmochoanal polyp with a brief review of the related literatures.
Ethmoid Sinus* ; Polyps* ; Recurrence