• Imaging Science in Dentistry
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• 제32권1호
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• pp.19-25
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• 2002

Purpose: To evaluate the degree of accuracy of DentaScan reformatted images of the maxillary sinus and periapical, periodontal lesions and to clarify the usefulness of the reconstructed 3-dimensional images to the dental clinical aspects. Materials and Methods: 33 sides of maxillae of the hemi-sectioned Korean heads were used in this study. Periapical radiographs, computed tomography and DentaScan reformatted cross-sectional images were taken for the radiographic evaluation of the peiapical and peiodontal lesions of the maxillary teeth and inferior wall of maxillary sinus. Results : Compared the degree of accuracy and findings of dental and periapical pathoses on the intraoral radiographs and DentaScan reformatted images with the cross-sectioned specimens, the DentaScan reformatted cross-sectional images were more accurate and more effective than the intraoral radiography with a viewpoint of the detection of dental and periapical pathoses. Conclusion: Comparing the lesions of specimens with intraoral radiographies and DentaScan reformatted images, the dental and periodontal pathoses and topographical structures were more clearly observed in the DentaScan reformatted images, providing the possibility of more applications of reformatted images to clinical dentistry.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.504-510
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• 2007

Purpose: The purpose of this study was to determine the incidence of antral septa and the accuracy of panoramic radiograph in identifying maxillary sinus septa. In addition, when panoramic radiograph led to a false diagnosis of more than majority, we analyzed findings of the panoramic radiograph. Patients and methods: This study included 180 patients who were radiographically examined before the surgery was done using both panoramic and computerized tomographic radiographs(CT scan), Samsung Medical Center from April 2003 to March 2006, and examined the incidence of antral septa, the false diagnosis rate of panoramic radiograph, and radiographic characters in case of false diagnosis. Only those bone lamellae were considered as septa that showed a height of at least 3.0mm. It was thus possible to exclude the alveolar recess. One oral and maxillofacial surgeon(OMFS) determined the presence or absence of sinus septa in CT scan, and five OMFS determined the presence or absence of sinus septa in panoramic radiograph. Results: The septa were observed in 81 of 360 sinuses(22.5%). All septa were oriented in a buccopalatal plane. More or less greater prevalence was observed in the second molar region(38.2%) but no predominant location was found. Panoramic radiograph led to false diagnosed septa in 361 of 1800 cases(20.1%). In case of false diagnosis of more than majority, superimposed image on zygomatic process was 44.1%, faint image in the region not related to sinus lifting 26.5%, faint image in the region related to sinus lifting 17.6%, and misconception for superimposed image 11.8% Conclusion: In this study we could get clinico-anatomical information of septum in the maxillary sinus. Compared to CT scan, panoramic radiograph can not clearly differentiate the sinus septa, but we consider that panoramic radiograph may improve its usefulness if we take additional modified panoramic radiograph and clinical exam.

• 치과방사선
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• 제29권1호
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• pp.241-254
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• 1999

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile. sensitivity. specificity and accuracy were considerably high(0.83. 0.86. 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권1호
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• pp.110-116
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• 2000

A 61-years old man with diabetes mellitus(DM) was admitted to our hospital, complaining of progressive right periorbital swelling, headache and toothache on the right lower second molar. On the first visit, moderate swelling was noticed from the right periorbital region with exophthalmos and subconjunctival effusion. Intraorally, right lower second molar had a severe periodontal disease and fistular formation on its distal area. From 3 days after hospitalization, the visual acuity of his right eye was gradually worsen and we performed CT scan. CT scan demonstrated an inflammatory change at the right orbit with subperiosteal abscess at the inferior orbital wall, which was extended from the right infratemporal, parapharyngeal and internal pterygoid space. Patient was treated by mean of intraoral(right upper vestibular and retromolar) and extraoral(infraorbital) incision and drainage, massive anti-therapy and DM control. The patient improved gradually and finally was discharged from the hospital, but his visual loss of right side was not recovered.

• 대한한방내과학회지
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• 제22권2호
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• pp.257-262
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• 2001

Cheiro-oral syndrome is characterized by a partial sensory disturbance in one hand and the ipsilateral oral comer. Its lesion is on the sensory track, and it is comparatively small. Most studies are case studies. These studies reported less than 10 cases. We studied two cases. In one, we observed intracranial hemorrhage involving left thalamus, posterior limb of internal capsule about 5cc in brain computed tomographic scan. The case was shown paresthesia of the right hand and ipsilateral comer of the mouth. The patient also complained about disturbing dysstereognosis and disorder of graphaesthesia. In the other case, we observed nodular calcification at the left basal ganglia external capsule in brain computed tomographic scan. The patient also complained about dysesthesia of the right thumb and index finger, fatigue and verbal disturbance. These cases appeared to be typical strokes in the acute phase, but after acute phase, they had dysethesia in the hand and periord for three months.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.100-107
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• 2010

Introduction: A cyst is a closed pathologic sac containing fluid or semi-solid material in central region. The most common conventional treatment for a cyst is enucleation. It was reported that spontaneous bone healing could be accomplished without bone grafting. We are trying to evaluate bone reconstruction ability by analyzing panorama radiograph and computed tomography (CT) scan with retrograde studying after cyst enucleation. In this way we are estimating critical size defect for spontaneous healing without bone graft. Materials and Methods: The study comprised of 45 patients who were diagnosed as cysts and implemented enucleation treatment without bone graft. After radiograph photo taking ante and post surgery for 6, 12, 18, 24 months, the healing surface and volumetric changes were calculated. Results: 1. Spontaneous bone healing was accomplished clinically satisfying 12 months later after surgery. But analyzing CT scan, defect volume changes indicate 79.24% which imply incomplete bone healing of defect area. 2. Comparing volume changes of defect area of CT scan, there are statistical significance between under $5,000mm^{3}$ and over $5,000mm^{3}$. The defect volume of $5,000mm^{3}$ shows $2.79{\times}1.91$cm in panoramic view. Conclusion: Bone defects, which are determined by a healed section using a panoramic view, compared to CT scans which do not show up. Also we can estimate the critical size of defects for complete healing.

• 산업경영시스템학회지
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• 제46권3호
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• pp.1-6
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• 2023

In the realm of dental prosthesis fabrication, obtaining accurate impressions has historically been a challenging and inefficient process, often hindered by hygiene concerns and patient discomfort. Addressing these limitations, Company D recently introduced a cutting-edge solution by harnessing the potential of intraoral scan images to create 3D dental models. However, the complexity of these scan images, encompassing not only teeth and gums but also the palate, tongue, and other structures, posed a new set of challenges. In response, we propose a sophisticated real-time image segmentation algorithm that selectively extracts pertinent data, specifically focusing on teeth and gums, from oral scan images obtained through Company D's oral scanner for 3D model generation. A key challenge we tackled was the detection of the intricate molar regions, common in dental imaging, which we effectively addressed through intelligent data augmentation for enhanced training. By placing significant emphasis on both accuracy and speed, critical factors for real-time intraoral scanning, our proposed algorithm demonstrated exceptional performance, boasting an impressive accuracy rate of 0.91 and an unrivaled FPS of 92.4. Compared to existing algorithms, our solution exhibited superior outcomes when integrated into Company D's oral scanner. This algorithm is scheduled for deployment and commercialization within Company D's intraoral scanner.

• 대한소아치과학회지
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• 제46권3호
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• pp.301-309
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• 2019

이 연구에서는 휴대용 정량광형광기인 Q-scan을 이용한 구강관리교육이 어린이가 구강관리를 하는데 있어서 얼마나 효과적인 지를 평가하였다. 6 - 12세의 어린이 중 치아우식위험도 검사결과 중위험 또는 고위험도로 분류된 58명을 대상으로 하였다. 대상자들을 Q-scan 사용군(I군)과 대조군(II군)의 두 군으로 나누고, Qray-cam을 이용하여 simple plaque score (SPS)를 평가한 뒤, 동일한 구강관리교육을 시행하였다. I군에게는 추가적으로 Q-scan을 매일 사용하게 하였다. 한 달 뒤 두 군 모두 SPS와 Cariview score를 재평가하였다. 두 군 모두 구강관리교육 후 Cariview score 및 SPS의 유의한 감소가 있었다(p < 0.001). 두 군 간의 변화된 Cariview score 차이는 유의하였고(p = 0.022), I군에서 II군 대비 감소폭이 더 컸으며, SPS 차이는 유의하지 않았다(p = 0.937). 어린이의 구강위생상태를 개선시키는 것은 기존의 구강관리교육만으로도 효과적이었다고 볼 수 있으나, 가정에서 휴대용 정량광형광기를 추가로 사용하는 것은 구강관리에 대한 어린이들의 행동변화를 유도하는 데에 도움을 주므로 더 효과적인 방법으로 볼 수 있다.

• 구강회복응용과학지
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• 제25권4호
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• pp.431-436
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• 2009

심한 치조골 흡수를 동반한 III급 악골 관계 환자의 총의치 제작의 경우 안정적이고 지속적인 교합을 제공하는 치료계획을 세워야 한다. 불리한 치관 대 치근 비와 임상적 동요도가 관찰되는 하악 잔존치를 고정하여 사용함으로써 환자의 불편감을 줄이고 시간적, 경제적으로 효율적인 치료를 제공할 수 있다. 본 증례에서는 상악 편악 무치악 환자의 기능적인 하악 운동과 조화로운 총의치 균형 교합을 이루기 위해 T-Scan System을 이용하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권3호
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• pp.139-144
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• 2012

This study was performed in order to evaluate the occurrence of temporomandibular joint disorder after surgical correction of skeletal class II malocclusion. Materials and Methods: This study included 21 patients who underwent orthognathic surgery for the correction of dentofacial deformities by a single surgeon at Mokdong Hospital, Ewha Womans University from 2000 to 2010. They underwent bilateral sagittal split ramus osteotomy for the treatment of undesirable mandibular advancement. The temporomandibular disorder (TMD) symptoms prior to surgery were recorded and the radiographic evaluation (panorama, bone scan, and magnetic resonance imaging [MRI]) of the post-surgery temporomandibular joint (TMJ) were assessed in order to evaluate condylar resorption, remodeling and disc displacement. The minimum follow-up period, including orthodontic treatment, was 12 months. Orthognathic procedures included 1-jaw surgery (n=8 patients) and 2-jaw surgery (n=13 patients). The monocortical plate was used for bilateral sagittal split ramus osteotomy fixation. Results: Among class II malocclusion patients with TMD symptom, clicking improved in 29.1%, and maximum mouth opening increased from $34.5{\pm}2.1$ mm to $37.2{\pm}3.5$ mm. The differences were not statistically significant, however. Radiographic changes in bone scan improved slightly based on the report by radiologist but not in TMJ dynamic MRI. Conclusion: No particular improvements were found in patients with joint sound only. Patients with limitation of mouth opening showed an increase in the degree of opening, but the difference was not statistically significant (P>0.05).