• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.477-491
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• 1999

Objectives : To evaluate the anatomic variations of the paranasal sinuses on computed tomographs. Materials and Methods : The author examined the CT images of the paranasal sinuses retrospectively in 500 patients who visited Chonbuk National University Hospital between January 1996 and December 1997. Results : The highest incidence of anatomic variation of the paranasal sinuses in bilateral structures was agger nasi cel1(73.2％), followed by concha bullosa(31.1％), Onodi cell(24.0％), Haller ce1109.8％), maxillary sinus septum(3.0％), paradoxical middle turbinate(2.5％), pneumatized uncinate process(2.0％), and bent uncinate process. The highest incidence of anatomic variation in midline structures was nasal septum deviation(53.2％), followed by nasal septum aerated(29.4％), bulla galli(24.7％) asymmetric intersphenoid septum(22.3％), and nasal septum spur(13.8％). The correlation between anatomic variation and paranasal sinusitis was not found. Conclusions : The results of this study will aid in the diagnosis and treatment of paranasal sinus diseases, especially in the treatment planning before functional endoscopic surgery.

• Korean Journal of Cleft Lip And Palate
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• v.5 no.2
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• pp.109-112
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• 2002

구순 구개열 환자의 악교정 성형수술로 구강내 Le Fort II 골절단술이나 비중격 성형술이 많이 이용되는데, 이때 비골의 외측골절단술을 요하며, 이에 대한 술 후 합병증으로 비루관의 폐쇄나 비골의 분쇄골절 등이 발생할 수 있어, 악안면기형 환자를 다루는 구강악안면외과의사에게 비루관의 웅용해부학적 연구는 중요하다. 본 연구의 목적은 교합면을 기준으로 촬영된 컴퓨터 단충 촬영에서 비루관의 위치와 크기를 조사하는데 있다. 2000년 7월부터 2003년 2월까지 서울대학교병원 구강악안면방사선과에서 컴퓨터 단층촬영을 시행한 환자 62명을 대상으로 비상악봉합선에서 비루관까지의 최단거리와 비루관의 최대반경과 최소반경을 측정하였다. 우측비상악 봉합선에서 비루관까지의 거리는 5.68mm이고, 좌측은 5.67mm였다. 좌우 및 성별간의 차이는 없었다. 이의 해부학적 지견은 악기형 수술시의 비루관 폐쇄라는 합병증의 예방책으로 기여하리라 생각된다.

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.107-119
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• 2005

Temporomandibular joint arthritides is divided into osteoarthritis, osteoarthrosis and polyarthritis. Because the signs, symptoms and radiographical features of osteoarthritis and osteoarthrosis are similar without arthralgia, diffenential diagnosis is difficult. Also non-radiographically change in early Osteoarthritis leads to misdiagnose. Planar bone scan and SPECT are useful to detect bone change early. This study was carried out in order to make diagnostic criteria of planar bone scan and SPECT. Three hundred and four temporomandibular joints were examined with clinical examination, computerized tomograph, planar bone scan, and SPECT. The obtained results were as follows. 1. If temporomandibular joint simple uptake ratio of patient in twenties is over 1.397%, it's condition may be osteoarthritis. And simple uptake ratio over in thirties-fourties may mean osteoarthritis. 2. It may mean osteoarthritis of temporomandibular joint that the number of coronal and transverse SPECT frame with hot spot is over four. 3. Destructive stage may goes on, if simple uptake ratio is over 1.370% in tweenties and over 1.104% in thirties-fourties. 4. If the number of coronal SPECT frame with hot spot is over four, temporomandibular joint may be on destructive stage in tweenties, thirties-fourties. And if the number of transverse SPECT frame with hot spot is over three, it may be on destructive stage in all ages. 5. When patient complains subjective arthralgia and palpation arthralgia, bone change may be more active than each arthralgia. 6. Osteoarthritis may progress gradually worse in 4.5 anamnesis. And then it may be stable gradually and turn to osteoarthrosis.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3275-3284
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• 1998

In this paper, we deseribe a Medical Image Information System. Our system stores and manages 5 dimensional medical image data and provides the 3 dimensional medical data via the Internet. The Internet standard VR format. VRML(Virtual Reality Modeling Language) is used to represent the 3I) medical image data. The 3D images are reconstructed from medical image data which are enerated by medical imaging systems such ans CT(Computerized Tomography). MRI(Magnetic Resonance Imaging). PET(Positron Emission Tomograph), SPECT(Single Photon Emission Compated Tomography). We implemented the medical image information system shich rses a surface-based rendering method for the econstruction of 3D images from 2D medical image data. In order to reduce the size of image files to be transfered via the Internet. The system can reduce more than 50% for the triangles which represent the surfaces of the generated 3D medical images. When we compress the 3D image file, the size of the file can be redued more than 80%. The users can promptly retrieve 3D medical image data through the Internet and view the 3D medical images without a graphical acceleration card, because the images are represented in VRML. The image data are generated by various types of medical imaging systems such as CT, MRI, PET, and SPECT. Our system can display those different types of medical images in the 2D and the 3D formats. The patient information and the diagnostic information are also provided by the system. The system can be used to implement the "Tele medicaine" systems.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.459-475
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• 1999

Objectives : The purpose of this study is to evaluate the computed tomographic (CT) images of the paranasal sinusitis(PNS). Materials and Methods : The author examined the extent and recurring patterns of the paranasal sinusitis and some important anatomic landmarks. The author analyzed PNS images retrospectively in 500 patients who visited Chonbuk National University Hospital between January 1996 and December 1997. Results : The most frequently affected sinus was maxillary sinus (82.9％), followed by anterior ethmoid sinus(67.9％), posterior ethmoid sinus(48.9％), frontal sinus(42.0％) and sphenoid sinus(41.4％). The characteristic features of CT images of the sinusitis were sinus opacification(22.4％), mucoperiosteal thickening(34.3％), and polyposis(2.0％). Sinonasal inflammatory diseases were categorized into 5 patterns according to Babber s classification. They were 1) infundibular(13.0％), 2) ostiomeatal unit(67.4％), 3) sphenoethmoidal recess (13.0％), 4) sinonasal polyposis (9.6％) and 5) unclassifiable patterns(18.0％). The incidences of contact between sinus and optic nerve were as follows ; the incidences of contact with posterior ethmoid sinus, sphenoid sinus. both posterior sinuses were 11.4％. 66.8％, 6.3％. respectively. The incidences of contact between sphenoid sinus and maxillary nerve, vidian nerve, internal carotid artery were 74.5％. 79.2％. 45.1％. respectively. The incidences of pneumatization of the posterior ethmoid sinus were as follows ; normal 70.6％ and overriding type 29.4％. The incidences of sphenoid sinus pneumatization were as follows; normal 56.9％ , rudimentary 12.5％, pterygoid recess 22.7％, anterior clinoid recess 2.7％, and both pterygoid and anterior clinoid recess type 5.2％. Conclusions : The inflammatory sinonasal diseases were classified into five patterns using the CT of PNS, which was proven to be an excellent imaging modality providing detailed information about mucosal abnormality, pathologic patterns, and the proximity of the important structures to the posterior paranasal sinuses. This result will aid in the interpretation of CT of PNS functionally and systemically.

• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.311-323
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• 2001

One of the various mechanics used to treat unilateral Class II malocclusion is head gear with asymmetric face bow. We made the finite element models of unilateral Class II maxillary dental arch and power arm asymmetric face bow. We designed this experiment to observe stress distribution of periodontal ligament, reaction force, and displacement and to understand force system, so to predict the therapeutic effect. On the basis of computerized tomograph of maxillary dental arch of 25 years old male with normal occlusion without extraction and orthodontic treatment history, we made finite element models of maxillary dental arch and periodontal ligament. Then we modified that model to unilateral maxillary Class II malocclusion model of which maxillary left molar displaced mesially. Also, We made finite element model of asymmetric face bow of which right outer bow shorter than left by 25mm(RMO, Penta-FormTM/Medium size, 0.045 inch iner bow, 0.072 inch outer bow). After that, retraction force of 250g, 300b, 350g were applied to maxillary first molar. We concluded as follow. 1. The Net force that both maxillary first molars were received increased as the retraction force increased. Mesially positioned tooth received more force than normally positioned tooth. But, both tooth were received distal force, so distal movement occured. 2. Both tooth received buccal lateral force. In analysis of force element, as the retraction force were increased, force of X-axis at mesially positioned tooth decreased, and force of X-axis at normally positioned tooth increased. so lateral force component moved to the side received less force from more force. 3. There were rotation, tipping with distal movement in maxillary first molar. As retraction force were increased, rotation and tipping also increased. More tipping and rotation occured at the side received more force, that is, mesially positioned tooth. Though it Is small change, displacement of same pattern occur in normally positioned tooth

• Journal of Oral Medicine and Pain
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• v.30 no.1
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• pp.57-67
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• 2005

The aim of this study was to evaluate bone scan(SUR) and SPECT(hot spot) in patients with TMJ osteoarthritis. 99mTc-MDP bone scan and SPECT were done in 27 patients, total 54 temporomandibular joints were examined with clinical examination, plain radiography. 42 TMJs were osteoarthritis and 12 TMJs were normal case, clinically diagnosed. We compared osteoarthritis group and control group of bone scan(SUR) and SPECT(hot spot). thus we compared before and after treatment of bone scan(SUR) and bone SPECT(hot spot) according to history, contributing factor, symptom degree, treatment, treatment period. The obtained results were as follows. 1. Bone scan(SUR) and SPECT(hot spot) activity of osteoarthritis group were higher than control group(P<0.05, P<0.01). 2. Bone scan(SUR) and SPECT(hot spot) activity were decreased after treatment at TMJ with osteoarthritis(P<0.01). 3. Bone scan(SUR) and SPECT(hot spot) activity were decreased at treatment group with splint(P<0.01, P<0.05). 4. Bone scan(SUR) and SPECT(hot spot) activity were decreased at Chronic group(P<0.01, P<0.05). 5. Bone scan(SUR) and SPECT(hot spot) activity were decreased at low noise NAS(<6) group(P<0.01,P<0.05). 6. Bone scan(SUR) and SPECT(hot spot) activity were decreased at TMD patient with parafunctional habit and without trauma history, psychosocial factor. 7. Bone scan(SUR) and SPECT(hot spot) activity were higher at before treatment required more treatment period.