• Imaging Science in Dentistry
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• v.33 no.3
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• pp.131-135
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• 2003

Purpose: To determine whether the mandibular radiomorphometric indices in panoramic radiography are correlated with the bone mineral density of Cu-equivalent images in intraoral film. Materials and Methods: The bone mineral density (BMD) of the mandibular premolar area was measured in the Cu-equivalent image of intraoral film. The Panoramic Mandibular Index (PMI) and Mandibular Cortical Width (MCW) were measured in panoramic radiographs of six dry mandibles, and the Pearson correlation between PMI, MCW, and BMD were tested. Results: There were no significant correlations between PMI and BMD (r = 0.280), nor between MCW and BMD (r =0.237). Conclusion: The results show that PMI and MCW were poor diagnostic indicators of mandibular BMD in the six dry mandibles used in this study. The correlationship between the mandibular radiomorphometric indices (PMI and MCW) and mandibular BMD needs to be researched further using large in vivo patient samples.

• Imaging Science in Dentistry
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• v.33 no.4
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• pp.211-215
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• 2003

Purpose: To assess the radiographic findings of odontogenic cysts showing displacement of the mandibular canal using computed tomographic (CT) and panoramic images. Materials and Methods : CT and panoramic images of 63 odontogenic cysts (27 dentigerous, 16 odontogenic keratocysts, and 20 radicular cysts) were analyzed to evaluate the following parameters: the dimension and shape of the cysts, and the effect of the cysts on the mandibular canal and cortical plates. Results: Of the 63 cysts examined in the study, 35 (55.6%) showed inferior displacement of the mandibular canal and 46 (73.0%) showed perforation of the canal. There were statistically significant differences between CT and panoramic images in depicting displacement and perforation of the mandibular canal. Cortical expansion was seen in 46 cases (73.0%) and cortical perforation in 23 cases (36.5%). The radicular cysts showed cortical expansion and perforation less frequently than the other cyst groups. Conclusion: Large cysts of mandible should be evaluated by multiplanar CT images inorder to detect the mandibular canal and cortical bone involvement.

• Journal of Korea Multimedia Society
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• v.6 no.6
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• pp.977-984
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• 2003

In this paper, we propose an image enhancement algorithm for panoramic infrared image. This method divides a panoramic infrared image into disjoint subimages and performs the contrast stretch for subimages using statistical characteristics of each subimage. But these cause blocking artifact in boundary regions of neighboring subimages which different to the statistical characteristic. To remove blocking artifact, we perform the contrast stretch for subimage's boundary regions using statistical characteristics of horizontally neighboring subimages. Experimental results show that the proposed method effectively improves their appearance to human viewers.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.400-403
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• 2003

This paper presents the signal processing of the panoramic thermal warning system that detects the small target such as aircraft and helicopter from afar. We develope the all round looking thermal imaging system which can scan all the way. This system acquires the panoramic images to reconstruct the IR images by revolving head of sensor typed line sensor at high speed. For detection, where the object of interest may be small, it is sometimes difficult to specify from object and background by conventional contrast enhancement methods. Therefore we use the adaptive plateau equalization algorithm each region to improve the contrast and make the hardware system which consists of the signal processing board for real-time display. We can verify the proposed method by the computer simulation and the hardware implementation.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2012.05a
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• pp.7-8
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• 2012

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.287-296
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• 1991

The purpose of this experiments is to compare the vertical and horizontal magnification, and the distortion of the radiographic image according to the types of panoramic machines. Total 70 radiographs, 10 radiographs out of 7 panoramic machines respectively, were taken from the dry skull with metal balls in the periapical areas of the central incisor, the canine, the second premolar, and the second molar in the maxilla and the mandible. And the author evaluated the vertical and horizontal magnification degrees, and the distortion degrees of radiographic images obtained from each panoramic machine. The results were as follows: There were no significant differences in the vertical and horizontal magnification degrees on the various portions of the jaws (p> 0.05). But there were higher magnification degrees in the Panoura 10C, Panograph Ⅱ, and Veraview than those in other panoramic machines. The lowest average magnification degree was 20.27% vertically, 20.94% horizontally using the Panoradix. The highest average magnification degree was 27.64% vertically, 28.48% horizontally using the Panograph Ⅱ. The lowest distortion was shown using the Panoura 10C in the maxilla, but there was not statistically significant difference between the panoramic machines in the mandible (p>0.05). There were no differences in the vertical and horizontal magnification degrees according to the types of the rotation centers.

• Imaging Science in Dentistry
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• v.43 no.3
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• pp.191-196
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• 2013

Purpose: This study assessed the accuracy of linear and angular measurements on panoramic radiographs taken at different positions in vitro. Materials and Methods: Two acrylic models were fabricated from a cast with normal occlusion. Straight and $75^{\circ}$ mesially and lingually angulated pins were placed, and standardized panoramic radiographs were taken at standard position, at an $8^{\circ}$ downward tilt of the occlusal plane compared to the standard position, at an $8^{\circ}$ upward tilt of the anterior occlusal plane, and at a $10^{\circ}$ downward tilt of the right and left sides of the model. On the radiographs, the length of the pins above (crown) and below (root) the occlusal plane, total pin length, crown-to-root ratio, and angulation of pins relative to the occlusal plane were calculated. The data were subjected to repeated measures ANOVA and LSD multiple comparisons tests. Results: Significant differences were noted between the radiographic measurements and true values in different positions on both models with linear (P<0.001) and those with angulated pins (P<0.005). No statistically significant differences were observed between the angular measurements and baselines of the natural head posture at different positions for the linear and angulated pins. Conclusion: Angular measurements on panoramic radiographs were sufficiently accurate and changes in the position of the occlusal plane equal to or less than $10^{\circ}$ had no significant effect on them. Some variations could exist in the pin positioning (head positioning), and they were tolerable while taking panoramic radiographs. Linear measurements showed the least errors in the standard position and $8^{\circ}$ upward tilt of the anterior part of the occlusal plane compared to other positions.

• Imaging Science in Dentistry
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• v.49 no.4
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• pp.287-294
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• 2019

Purpose: This study was performed to analyze the clinical and imaging features of contemporary osteomyelitis(OM) and to investigate differences in these features on panoramic radiography according to patients' history of use of medication affecting bone metabolism. Materials and Methods: The records of 364 patients(241 female and 123 male, average age 66.8±14.9 years) with OM were retrospectively reviewed. Panoramic imaging features were analyzed and compared between patients with medication-related OM(m-OM) and those with conventional, medication-unrelated OM(c-OM). Results: The age of onset of OM tended to be high, with the largest number of patients experiencing onset in their 70s. The 2 most frequent presumed causes were antiresorptive medication use (44.2%) and odontogenic origin (34.6%). On panoramic radiographs, a mix of osteolysis and sclerosis was the most common lesion pattern observed (68.6%). Sequestrum, extraction socket, and periosteal new bone formation were found in 143(42.1%), 79 (23.2%), and 24 (7.1%) cases, respectively. The m-OM group exhibited sequestrum and extraction socket more frequently and displayed significantly higher mandibular cortical index values than the c-OM group. Conclusion: We observed some differences in imaging features as shown on panoramic radiography according to the history of antiresorptive medication use. This study may help elucidate the predictive imaging features of medication-related osteonecrosis of the jaw.

• Journal of KIISE
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• v.42 no.10
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• pp.1185-1194
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• 2015

A spherical panoramic image does not conform to the pin-hole camera model, and, hence, it is not possible to utilize previous techniques consisting of plane-to-plane transformation. In this paper, we propose a new method to estimate the planar geometric transformation between the planar image and a spherical panoramic image. Our proposed method estimates the transformation parameters for latitude, longitude, rotation and scaling factors when the matching pairs between a spherical panoramic image and a planar image are given. A planar image is projected into a spherical panoramic image through two steps of nonlinear coordinate transformations, which makes it difficult to compute the geometric transformation. The advantage of using our method is that we can uncover each of the implicit factors as well as the overall transformation. The experiment results show that our proposed method can achieve estimation errors of around 1% and is not affected by deformation factors, such as the latitude and rotation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7187-7192
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• 2014

Recently, theservice field based on the location while expanding into a variety of business areas and have generated significant revenue. In particular, the map service provides a variety of information in conjunction with such public transport directions. Therefore, this study evaluated the map service, as one of the key technologies, StreetView and LoadView photographs of panoramic photograph-support service-modules that can be supported on smart phones. For this, purpose sensors were provided to allow smart phone users to easily publish panoramic photographs. The unnecessary parts could be removed from several photos and pictures using the design technology, and the naturalness of the connection could be maintained by applying the algorithm to handle a single photograph. Finally, a system to work with smartphone panoramic photographs was configured and designed to operate a smartphone application panoramic photograph for 6 months.