• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.3
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• pp.152-159
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• 2012

Objectives: This study evaluated bisphosphonate-related osteonecrosis of the jaws (BRONJ) in patients diagnosed with malignant bone tumors. Demographic findings, laboratory, and radiographic analyses were performed to characterize disease severity and progression. Materials and Methods: Patients who had been diagnosed with BRONJ (2005-2010) at the authors' hospital according to the American Association of Oral and Maxillofacial Surgeons were investigated. Twenty-one patients (12 with multiple myelomas, 7 with breast cancer, and 2 with prostate cancer) who had been treated with bisphosphonates (BPs) for malignant bone tumors were included. Radiographic evaluations with a panorama, computed tomography, whole body bone scan, and laboratory findings were evaluated for erythrocyte sedimentation rate (ESR), c-reactive proteins (CRPs), and c-terminal cross-linked telopeptides (CTXs). Results: The average age of the patients was 64.3 (range 51-80), and they were treated with BPs for an average of $35{\pm}19$ months before BRONJ was diagnosed. Types of BPs were zolendronic acid (81%, intravenous [IV]), pamidronate (4.8%, IV), zoledronic acid+pamidronate (4.8%, IV), alendronate (4.8%, per os [PO]), and ibadronate (4.75%, PO). Extraction (67%) and persistent irritation of dentures (20%) were the most common triggering factors. BRONJ in the mandible was reported in 62% of the cases, in the maxilla 24%, and both 14%. BRONJ occurred more frequently in patients with multiple myelomas (n=12, 57.1%). Most of the patients revealed an advanced BRONJ stage; Stage I (n=2, 9%), Stage II (n=13, 62%), and Stage III (n=6, 29%). Conclusion: The differences of the ESR, CRP, and CTX values between the BRONJ-recurring and non-recurring patients after the treatment were not evident. Later stage BRONJ patients showed lower CTX levels. A drug holiday after the diagnosis of BRONJ did not remarkably influence the surgical outcomes. However, the limited number of patients in the study should be considered.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.79-83
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• 2012

Burkitt's lymphoma is a malignant tumor originated from B lymphocyte and a type of non-hodgkin lymphoma. It is clinically classified by endemic, sporadic and immune deficient forms. In the past, it had poor prognosis but in recent years survival rate is 50~80% treated by intensive chemotherapeutic regimens. Mostly it is a lesion of the jaws. Clinical symptoms are severe tooth mobility, displacement, gingival redness and swelling. This case is about a patient with aggressively progressing Burkitt's lymphoma of the jaws. Initial diagnosis was done in dental hospital and it has shown satisfactory outcome by prompt and appropriate treatment.

• Imaging Science in Dentistry
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• v.35 no.2
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• pp.111-114
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• 2005

A 15-year-old patient, who had been diagnosed and treated as Burkitt cell type acute lymphoblastic leukemia (ALL-L3) already, visited our department. He complained of gingival enlargement and loosening teeth 1 month ago. The clinical examination revealed anterior open bite, gingival enlargement, and nontender swelling particularly in molar regions of both jaws. Deep periodontal pockets and severe mobility was shown on most of the teeth. The panoramic radiographs showed severe bone destruction and extrusion of the molars. The contrast enhanced CT showed multiple enhanced mass and bone marrow obliteration in both jaws. Chemotherapy was done and the swelling was subsided at 1 month later. In conclusion, radiologic findings of leukemia with soft tissue mass, known as chloroma or granulocytic sarcoma, mimic those of lymphoma, so blood test may be needed for the final diagnosis.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.311-316
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• 2006

A scissors bite in the posterior teeth occurs when the upper teeth are positioned totally or unilaterally buccal to the lower teeth in centric occlusion. This malocclusion can result from either excessive width of maxilla, deficient width mandible, or combination of both. The malocclusion can lead to hindered growth of jaws or to asymmetry between the jaws, Besides, the severe lingual inclination of the mandibular posterior teeth prevents adequate mastication. Thus, the scissors bite is in need of immediate interceptive orthodontic intervention. The common treatments of the scissors bite is to expand the mandibular arch: fixed or removable appliances. In our clinic, we made a success in treatment of the scissors bite using the Schwarz appliance. We treated the scissors bite using the lower Schwarz appliance for a mean observation period of 21 months. The subjects were 2 boys, aged 4 years.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.533-538
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• 1998

[ $Garr{\grave{e}}'s$ ] osteomyelitis is a chronic form of osteomyelitis in which periosteum is thickened with peripheral reactive bone formation. Carl $Garr{\grave{e}}$ first reported localized periosteal thickening as a response to mild stimuli. In dental literatures, Pell et al. first reported $Garr{\grave{e}}'s$ osteomyelitis in jaws. This disease frequent occurs in youngsters and usually in mandible. It usually results in hard swelling over the jaws with little or no pain. Palpation reveals a localized bony swelling lesion. In radiographic findings, it usually reveals laminated periosteal thickening on lesion. The treatment of $Garr{\grave{e}}'s$ osteomyelitis usually consists of elimination of the sources of infection, i.e., either extraction of an infected teeth or root canal therapy. Two children were admitted with the chief complaint of intraoral swelling on lower deciduous molar areas which was diagnosed as $Garr{\grave{e}}'s$ osteomyelitis. The root canal therapy and antibiotic therapy were performed and prognosis was checked. From these case studies, some results were obtained as follows : With the aid of root canal therapy and antibiotic administration, the size of periapical lesions was reduced, the mandible with bony swelling recovered its normal shapes radiographically, and the permanent tooth germs resumed sound development.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.61-68
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• 1996

In Fibrous dysplasia(FD) of the jaws, the majority of cases can await the cessation of growth before surgical intervention, and it seems prudent to delay surgery whenever possible until growth has ceased. In craniofacial FD, however, the dangers of dystopia, dystopia and loss of vision may require early surgery to prevent or control cranio-orbital complications. Delaying surgery in those circumstances may be significantly detrimental to such patients. Conservative surgical management of FD is widely practised and we advocate an extension to this conservative treatment by combining surgical recontouring with appropriate osteotomies if indicated, to achieve an optimal esthetic and functional results in craniofacial FD. One case will be presented to illustrate the feasiblility of such combined treatment, to report the uneventful healing of osteotomies in the FD of the jaws, and to demonstrate the use of titanium miniplate fixation in dysplastic bone. The other case had expansile disease of the left facial and fronto-temporal bones and osteolytic change left mandible. This patient complained of severe spontaneous bleeding of left mandibular premolar area and it was suspected as central hemangioma of the left mandible and craniofacial FD. Angiogram disclosed generalized dilation of the external carotid artery and its branches, especially terminal branches of the left facial and inferior alveolar arteries. But no specific abnormalities, such as A-V shunt, venous lake, or early venous drainage, was seen. So it was diagnosed craniofacial FD with hypercellularity and generalized bony recontouring was performed via coronal and transoral approaches.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.19-32
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• 1996

The purpose of this study was to know the proper diagnosis and to establish the treatment plan of the osteosarcoma in the jaws through the clinical, radiological, and histopathologic considerations. The authors compared and analyzed the clinicoradiologic features of the six cases of osteosarcoma, diagnosed at the Dental college hospital in Yonsei University, Seoul, Korea, during the period from 1975 to 1995. The obtained results were as follows; 1. Osteosarcoma occurred in the mean age, 26.2 years, ranged from 14 to 35 years, and equally in men and women. 2. The swelling was the most common frequent presenting complaints. Other reported symtoms included pain, parasthesia of the lower lip or the lesion. 3. The average interval was seen 3.5 months before the patient had been seen by a doctor. 4. The frequency of the lesions was equally in the maxilla, 3 cases and mandible, 3 cases. 5. Radiologically, osteolytic lesions were 2 cases, mixed lesion 1 case, and sclerotic lesion were 3 cases. Periosteal reaction features were shown in 4 cases. A widening of the periodotnal lignament space, one of the earliest signs were shown in 2 cases. 6. Histopathologically, osteoblastic osteosarcoma which is seen in the 3 cases was the most frequent histologic type. Chondroblastic osteosarcoma were seen in the 2 cases. There was no correlation between the radiologic appearance and hitopathologic type.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2223-2228
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• 2014

Available shafts with gears at each end of the cylinder-shaped steel are widely used as power train components for automobiles. In order to automate the production of a geared shaft, there are problems to be solved. After one side of the cylinder is cut in gears, one of the problems is to determine the position of the cylinder which has been already cut. The shaft is then to be fed ahead with geared position to the chuck with jaws in geared shape. The other problem is to acquire information on an angular position of the shaft to fit to the jaws of the chuck. This paper deals with the magnetic detection sensor of gear position. Coils are installed in two places. Self-inductances of coils are detected by the changes of reluctance and are then compared. The magnetic analysis also has been carried out by the finite element analysis (FEM).

• The Journal of Advanced Prosthodontics
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• v.11 no.3
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• pp.179-186
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• 2019

PURPOSE. The purpose of this study was to compare two novel impression methods and a conventional impression method for edentulous jaws using 3-dimensional (3D) analysis software. MATERIALS AND METHODS. Five edentulous patients (four men and one woman; mean age: 62.7 years) were included. Three impression techniques were used: conventional impression method (CI; control), simple modified closed-mouth impression method with a novel tray (SI), and digital impression method using an intraoral scanner (DI). Subsequently, a gypsum model was made, scanned, and superimposed using 3D analysis software. Mean area displacement was measured using CI method to evaluate differences in the impression surfaces as compared to those values obtained using SI and DI methods. The values were confirmed at two to five areas to determine the differences. CI and SI were compared at all areas, while CI and DI were compared at the supporting areas. Kruskal-Wallis test was performed for all data. Statistical significance was considered at P value <.05. RESULTS. In the comparison of the CI and SI methods, the greatest difference was observed in the mandibular vestibule without statistical significance (P>.05); the difference was < 0.14 mm in the maxilla. The difference in the edentulous supporting areas between the CI and DI methods was not significant (P>.05). CONCLUSION. The CI, SI, and DI methods were effective in making impressions of the supporting areas in edentulous patients. The SI method showed clinically applicability.

• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.15-19
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• 2023

Background: Cone beam computed tomography (CBCT) is a specialized medical equipment and plays a significant role in the diagnosis of oral and maxillofacial diseases and abnormalities; however, it is attributed to risk of exposure of ionizing radiation. The aim of the study was to estimate and determine the amount of scattered radiation dose to the thyroid gland in dental CBCT during maxilla and mandible scan. Materials and Methods: The average scattered radiation dose for i-CAT 17-19 Platinum CBCT (Imaging Sciences International) was measured using a Multi-O-Meter (Unfors Instruments), placed at the patient's neck on the skin surface of the thyroid cartilage, with an exposure parameter of 120 kVp and 37.07 mAs. The surface entrance dose was noted using the Multi-O-Meter, which was placed at the time of the scan at the level of the thyroid gland on the anterior surface of the neck. Results and Discussion: The surface entrance dose to the thyroid from both jaws scans was 191.491±78.486 µGy for 0.25 mm voxel and 26.9 seconds, and 153.670±74.041 µGy from the mandible scan, whereas from the maxilla scan the surface entrance dose was 5.259±10.691 µGy. Conclusion: The surface entrance doses to the thyroid gland from imaging of both the jaws, and also from imaging of the maxilla and mandible alone were within the threshold limit. The surface entrance dose and effective dose in CBCT were dependent on the exposure parameters (kVp and mAs), scan length, and field of view. To further reduce the radiation dose, care should be taken in selecting an appropriate protocol as well as the provision of providing shielding to the thyroid gland.