• 치과방사선
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• 제23권2호
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• pp.265-275
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• 1993

The purpose of this study was to compare the interpretation results of the panoramic radiographs with those of intraoral radiographs in evaluation of alveolar bone loss. All radiographs were obtained from 100 patients who had visited the Dental Infirmary of Kyungpook National University Hospital for periodontal state evaluation. The results were as follows: The percentages of interpretable sites were 95.9%(94.6% in maxilla, 97.4% in mandible) on the intraoral radiographs, and 90.7%(84.0% in maxilla, 97.3% in mandible) on the panoramic radiographs. The concordance of interpretation scores of marginal bone loss between intraoral and panoramic radiographs was 66.3%(65.6% in maxilla, 66.8% in mandible). And according to the site, the highest concordance was in the distal surface of the mandibular 2nd premolar at 82.0%, and the distal surface of the mandibular 1st premolar(76.8%), the distal surface of the maxillary central incisor(75.8%), the mesial surface of the 2nd premolar (75.0%) in descending order of frequency. According to the interpretation scores of the marginal bone loss, the percentages of concordance between intraoral and panoramic radiographs were the highest on the score 10 at 76.4%, and the lowest on the score 8, 9. And the percentages of concordance were inverse proportional rate from the score 5 to the score 9. Number of the observed sites of the furcation involvement in bitewing and panoramic radiographs were 268 sites, and the percentage of interpretable sites was 92.9% in bitewing radiographs and 86.6% in panoramic radiographs. And the concordance rate of interpretation was 79.5%.

• 치과방사선
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• 제23권2호
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• pp.277-285
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• 1993

This study was performed to evaluate the role of Waters' view and panoramic view for the interpretation of mucosal cyst of the maxillary sinus and to determine the radiographic features of that according to the sites and sizes. For this study, clinically 25 cases of mucosal cyst of the maxillary sinus were used, and experimentally with two dry skulls, rubber ball of 15mm in diameter for marked radiopacity, and two jelly balls of 8 and 20㎜ in diameter for the similar radiopacity to cyst were used. The 25 cases with 25 panoramic views and 15 Waters' views were first analyzed, and secondly, the radiographic features of artificial lesions attached to the each wall of the antrum on Waters' view and panoramic view were analyzed. The obtained results were as follows: At clinical analysis, 1. 4 cases of 13-14㎜, 4 cases of 15-19mm, 14 cases of 20-25㎜, 3 cases of over 30㎜ in dia- meter were found on panoramic views. And 24 cases of 25 cases showed no relationship with teeth, and only 1 case was associated with advanced periodontal disease 2. The majority of mucosal cysts appeared to arise the posterior portion of the floor of the sinus and were superimposed with the inominate line of zygoma and the horizontally linear image of hard palate on panoramic view. 3. Only 2 cases of 15 cases were identified on both films. At experimental analysis, 4. On Waters' view, the images of the artificial lesion of the anterior portion and midportion of the floor of the sinus were lessend in diameter compared with the real size. On panoramic views, the images of the lesion were more radiolucent with lessened diameter than images on Water' view. 5. The images of the lesion of the posterior wall and the posterior portion of the floor of sinus on panoramic view were well detected by the preeducated group but not or poorly detected by the non-preeducated observer group. 6. On Waters' view, both observer groups recognized that the cystic images of the posterior portion of the floor of the maxillary sinus were superimposed with the petrous portion of the skull.

• Imaging Science in Dentistry
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• 제42권4호
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• pp.231-235
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• 2012

Purpose: This study was performed to evaluate the trabecular pattern on panoramic radiographs to predict age-related osteoporosis in postmenopausal women. Materials and Methods: Thirty-one postmenopausal osteoporotic women and 25 postmenopausal healthy women between the ages of 50 and 88 were enrolled in this study. The bone mineral density (BMD) of the lumbar vertebrae and femur were calculated using dual-energy X-ray absorptiometry (DXA), and panoramic radiographs were obtained. Fractal dimension (FD) was measured using the box counting method from 560 regions of interest ($51{\times}51$ pixels) in 6 sites on the panoramic radiographs. The relationships between age and BMD and between FD and BMD were assessed, and the intraobserver agreement was determined. Results: There was a significant difference in the FD values between the osteoporotic and normal groups (p<0.05). There was a significant difference in the FD values at three sites in the jaws (p<0.05). Age was significantly correlated with the BMD measurements, with an odds ratio of 1.25. However, the FD values were not significantly correlated with the BMD measurements, with an odds ratio of 0.000. The intraobserver agreement showed relatively higher correlation coefficients at the upper premolar, lower premolar, and lower anterior regions than the other sites. Conclusion: Age was an important risk factor for predicting the presence of osteoporosis in postmenopausal women. The lower premolar region was the most appropriate site for evaluating the FD value on panoramic radiographs. However, further investigation might be needed to predict osteoporosis using an FD value on panoramic radiographs.

• Imaging Science in Dentistry
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• 제39권3호
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• pp.157-161
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• 2009

Purpose : This study aimed to investigate the luminal stenosis of the internal carotid artery with calcification detected on panoramic radiographs. Materials and Methods : This study used fifty carotid arteries of 36 dental patients whose panoramic radiograph and computed tomography angiography (CTA) revealed the presence of carotid artery calcification. A neuroradiologist interpreted CTA to determine the degree of stenosis of the internal carotid arteries. The degree of stenosis was stratified in four stages; normal (no stenosis), mild stenosis (1-49%), moderate stenosis (50-69%) and severe stenosis (70-99%). Results : Among the fifty carotid arteries with calcification detected on both panoramic radiography and CTA, 20 carotid arteries (40%) were normal, 29 carotid arteries (18%) had mild stenosis, 1 carotid artery (2%) had moderate stenosis, and there was none with severe stenosis. Conclusion : Sixty percent of the carotid arteries with calcification detected on both panoramic radiography and CTA had internal luminal stenosis, and two percent had moderate stenosis. When carotid atheroma is detected on panoramic radiograph, it is possible that the dental patient has luminal stenosis of the internal carotid artery.

• 치과방사선
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• 제28권1호
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• pp.7-16
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• 1998

The Scanora/sup (R)/ X-ray unit uses the principles of narrow beam radiography and spiral tomography. Starting with a panoramic overview as a scout image. multiple tomographic projections could be selected. This study evaluated the accuracy of spiral tomography in comparison to routine panoramic radiography for dental implant treatment planning. An experimental study was performed on a cadaver mandible to assess the accuracy of panoramic radiography and spiral tomography film images for measurement of metallic spheres. After radiographic images of the metallic spheres on the surgical stent were measured and corrected for a fixed magnification of radiographic images. following results were obtained. 1. In the optimal position of the mandible. the minimal horizontal and vertical distortion was evident in the panoramic radiography images. The mean horizontal and vertical magnification error in anterior sites was 5.25％ and 0.75％. respectively. The mean horizontal and vertical magnification error in posterior sites was 0.50％ and 1.50％. respectively. 2. In the displaced forward or in an eccentric position of the mandible. the magnification error of the panoramic radiography images increased significantly over the optimal position. Overall, the mean horizontal magnification error of the anterior site in the different positions changed dramatically within a range of -17.25％ to 39.00％, compared to the posterior range of -5.25％ to 8.50％. However, the mean vertical magnification error stayed with the range of 0.5％ to 3.75％ for all the mandibular positions. 3. The magnification effects in the tomographic scans were nearly identical for the anterior and posterior with a range of 2.00％ to 5.75％ in the horizontal and 4.50％ to 5.50％ in the vertical dimension, respectively. 4. A statistically significant difference between the anterior and posterior measurements was found in the horizontal measurements of the panoramic radiography images of the displaced forward and backward position of the mandible(P<0.05). Also a significant difference between the optimal panoramic and tomographic projections was found only in the vertical measurement(P<0.05).

• 한국통신학회논문지
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• 제39B권9호
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• pp.590-597
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• 2014

본 논문은 고품질 파노라마 영상 획득을 위하여 대상 공간을 여러 대의 카메라로 촬영 시, 촬영 정보를 제공하는 모니터링 시스템과 클라우드 컴퓨팅을 이용한 생성 과정 분산 처리에 관한 것이다. 파노라믹 비디오의 특성상 이웃 카메라 간 일정한 중복영역을 가져야 하지만 이로 인하여 동일한 촬영 대상에 대해 촬영 화각이 다르고, 카메라의 물리적인 크기로 인하여 촬영 중심점을 동일하게 맞추기 어려운 상황에서 2D 입력 영상기반으로 모니터링 하여 카메라를 보정하는 경우 시차원인으로 오보정이 발생하는 문제가 있다. 이를 해결하기 위하여 카메라별 촬영 화각에 따라 3차원으로 투영하여 모니터링 함으로써 카메라 오보정 문제를 최소화하고 획득 영상의 품질을 높이는 3차원 기반 모니터링 시스템을 제안한다. 또한 여러 영상을 하나의 영상으로 합성하는 파노라믹 비디오 생성알고리즘은 합성 정보추출과 합성, 두 부분으로 나눌 수 있는데 이를 클라우드와 클라이언트에 적절히 분산하여 고화질의 파노라믹 비디오를 효율적으로 서비스 하는 방법에 대해 제안한다.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.271-278
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• 2021

Purpose: This study aimed to investigate the panoramic imaging features of cleidocranial dysplasia (CCD) with a relatively large sample. Materials and Methods: The panoramic radiographs of 40 CCD patients who visited Seoul National University Dental Hospital between 2004 and 2018 were analyzed. Imaging features were recorded based on the consensus of 2 radiologists according to the following criteria: the number of supernumerary teeth and impacted teeth; the shape of the ascending ramus, condyle, coronoid process, sigmoid notch, antegonial notch, and hard palate; the mandibular midline suture; and the gonial angle. Results: The mean number of supernumerary teeth and impacted teeth were 6.1 and 8.3, respectively, and the supernumerary teeth and impacted teeth were concentrated in the anterior and premolar regions. Ramus parallelism was dominant (32 patients, 80.0%) and 5 patients (12.5%) showed a mandibular midline suture. The majority of mandibular condyles showed a rounded shape (61.2%), and most coronoid processes were triangular (43.8%) or round (37.5%). The mean gonial angle measured on panoramic radiographs was 122.6°. Conclusion: Panoramic radiographs were valuable for identifying the features of CCD and confirming the diagnosis. The presence of numerous supernumerary teeth and impacted teeth, especially in the anterior and premolar regions, and the characteristic shapes of the ramus, condyle, and coronoid process on panoramic radiographs may help to diagnose CCD.

• Imaging Science in Dentistry
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• 제49권2호
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• pp.115-122
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• 2019

Purpose: The aims of this study were first, to compare panoramic radiography with cone-beam computed tomography (CBCT) for evaluating topographic relationships, such as the classification of maxillary posterior teeth and their distance to the maxillary sinus floor; and second, to determine the relationship between maxillary sinus pathology and the presence of apical lesions. Materials and Methods: In total, 285 paired CBCT and panoramic radiography records of patients (570 maxillary sinuses) were retrospectively analyzed. Both imaging modalities were used to determine the topographic relationship of the maxillary posterior teeth to the sinus floor. Mucosal thickening >2 mm was considered a pathological state. Data were analyzed using the chi-square, Wilcoxon, and Mann-Whitney U tests. Odds ratios (ORs) and confidence intervals(CIs) were calculated. Results: The closest vertical distance measurements made between posterior maxillary teeth roots and the maxillary sinus on panoramic radiography and CBCT scans showed statistically significant differences from each other(P<0.05). Compared to panoramic radiography, CBCT showed higher mean values for the distance between the maxillary sinus floor and maxillary posterior teeth roots. The CBCT images showed that at least 1 apical lesion adjacent to the right maxillary sinus increased the risk of maxillary sinus pathology by 2.37 times(OR, 2.37; 95% CI, 1.58-3.55, P<0.05). Conclusion: Panoramic radiography might lead to unreliable diagnoses when evaluating the distance between the sinus floor and posterior roots of the maxillary teeth. Periapical lesions anatomically associated with maxillary sinuses were a risk factor for sinus mucosal thickening.

• Imaging Science in Dentistry
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• 제34권1호
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• pp.25-30
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• 2004

Purpose: Several panoramic indices have been suggested to assess bone quality from the morphology and width of mandibular cortex on panoramic radiography. The purpose of this study was to compare dental implant failure group with control group in panoramic mandibular index (PMI), mandibular cortical index (MCI), and gonion index (GI) and to determine the effect of these panoramic indices on dental implant failure. Materials and Methods: A case-control study was designed. Test group (n=42) consisted of the patients who had their implants extracted because of peri-implantitis. Control group (n=139) consisted of the patients who retained their implants over one year without any pathologic changes and had been followed up periodically. They had dental implants installed in their mandibles without bone augmentation surgery from 1991 to 2001. The following measures were collected for each patients: 1) PMI, MCI, and GI were measured twice at one-week interval on preoperative panoramic views; and 2) age, sex, implant length, implant type, installed location, occluding dentition state, and complication were investigated from the chart record. Results: The PMI showed moderate level of repeatability. The intra-observer agreement of MCI and GI were good. There was statistically significant difference in PMI between two groups. There were significant different patterns of distribution of MCI and GI between two groups. Among the panoramic indices, PMI and MCI showed significant correlation with dental implant failure. Conclusion: Panoramic indices can be used as reference data in estimating bone quality of edentulous patients who are to have implants installed in their mandibles.

• 대한소아치과학회지
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• 제44권2호
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• pp.129-137
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• 2017

본 연구의 목적은 파노라마 영상과 측모두부 영상에서 유의미한 상관관계를 가지는 계측치를 확인하고, 그 관계를 수식화하는 것이다. 99명의 3급 부정교합 환자의 파노라마 영상과 측모두부 영상에서 gonial angle, 하악지 높이, 하악중절치에서 하악하연까지의 길이를 측정하여 평가하였다. 측정된 수치는 각각 대응 표본 T검증, Pearson's 상관관계 검정, 회귀 분석을 통해 평가하였다. 측모두부 영상에서의 gonial angle 평균값은 $127.50^{\circ}$, 파노라마 영상에서의 값은 $125.49^{\circ}$, 상관계수는 0.945(p < 0.001)로 나타났으며, 상관관계는 '측모두부 영상의 gonial angle = 0.920 ${\times}$ 파노라마 영상의 gonial angle + 12.072'로 나타낼 수 있다. 다른 계측치들 간의 상관관계는 gonial angle에 비해 낮게 나타났다. Gonial angle은 파노라마 영상과 측모두부 영상에서 모두 재현성 있게 측정 가능하며, 강한 양의 상관관계를 나타낸다. 파노라마 영상 또한 측모두부 영상과 같이 환자의 수직성장패턴을 평가하는데 도움을 주는 방법이다.