• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.4
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• pp.219-225
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• 2003

Purpose: Platelet Rich Plasma(PRP) application is increasing with sinus inlay bone graft, but there is few research with radiographic ananlysis on effect of PRP in maxillary sinus. The author investigated the amount of bony changes of maxillary sinus for dental implantation among the patients with maxillary inlay graft. Materials and Methods: With 10 patients who were treated with sinus inlay autologous bone grafting combined with PRP technique, and with 5 patients who were treated with sinus inlay grafting only without PRP, the panoramic radiographys which were taken at preoperation, immediate postoperation, 3months postoperation, and 4 months postoperation(a month after dental implantation)periods were analysed. The films had been scanned, and then proceeded throughout image analysis system. The bone density of maxillary grafted sites was compared with adjacent tooth enamel density and remeasured according to density luminosity of each film. The density changes on PRP group and bone graft only group were analysed with non-parameteric statistics method. Results: In PRP combined patients group, bone density on postoperation periods was increased totally. The remarkable enhanced change of bone density was observed on 3 months postoperation period, thereafter the increasing rate was slightly reduced. In only bone graft patients group, bone density on postoperation periods was also increased compared with preoperation period, but the bone density of 4 months postoperation period was decreased compared with 3 months postoperation period. The amount of bone density on PRP group was significantly changed according to periods in contrast to bone graft only group. Conclusion: The bone density on PRP group was remarkably increased at 3 months postoperation compared to bone graft only group and it was seemed to be associated with more new bone formation, less grafted bone resorption at bone grafted sites with PRP.

• Journal of the Korean Society of Radiology
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• v.9 no.7
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• pp.433-438
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• 2015

To evaluate the radiation exposure level based on radiation workers' locations in dental radiography, the radiation dose rate in the radiographic room, lead glass, and operation system was measured. To that end, various devices were used, such as a Standard(Max-GLS, Shinhung), a panorama (PCH-2500, Vatech), a cephalometric radiography (PCH-2500), and a cone beam CT (PHT-30LFO, Vatech), as well as a PM1405 equipment as a radiation meter. Radiography conditions were set the same as the factors used in the clinical setting. As the result, the cone beam CT turned out the highest with 98 uSv and the standard showed the lowest level with 0.4 uSv/h. The panorama was measured to be higher than the Cephalo due to its different focus mode. On the lead glass surface and in the operation stand, the oral radiography device, panoramic, and Cephalo all were measured below the recording level. However, the cone beam CT was measured to have the leakage dose. Thus, radiation involved workers should be equipped with appropriate protection tools and reduce radiography time as much as possible. In addition, the structure of the radiation chamber should be also designed efficiently. Dental radiography has continued to grow in recent years, so it is necessary take appropriate protection measures for patients and radiation workers.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.369-375
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• 2011

In dental radiography, panoramic views cause distortion and thus may bring about inaccurate results in the process of quantitative analysis. In this connection, there has recently been an increasing use of cone beam computed tomography (CBCT) that is known to provide high-resolution images and positional information. In this study, a dental computed tomography unit, 'DCT-90-P IMPLAGRAPHY (Vatech, Korea)', was applied to 20 patients for 24 seconds respectively, with a tube voltage of 85kVp and a tube current of 7mA. The data of CBCT were three-dimensionally reconstructed by use of a computer program, and were histomorphometrically analyzed. The results showed that the diameter of mandibular canal is less distorted at a certain inclination of the mandibular body. The image tends to seem more distended in proportion to the distance between the subject and film. Also, the image tends to be affected according as it is out of focus. In conclusion, it requires that the image should be reconstructed in light of anatomic position and structure.

• Journal of Korean society of Dental Hygiene
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• v.23 no.6
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• pp.431-439
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• 2023

Objectives: The aim of this study was to investigate the essential services, importance, interval of examinations, and role of dental hygienists in children's family dentistry program. Methods: A total of 124 participants completed a self-administered questionnaire. The data were analyzed using independent t-test, and ANOVA, and Pearson correlation analysis. Results: All participants stated that oral examination and panoramic radiography are required; children should be educated about brushing, use of oral products, and regular check-ups; and preventive treatments such as molar sealants and prophylaxis should be offered. They stated that light-curing resins and glass ionomer fillings should be offered in treatment services. They stated that examination intervals should be shorter for education and prevention rather than treatment. Dental hygiene students were more likely than dentists and dental hygienists to say that the program was more important. There was a correlation between oral examinations and education and treatment, and between essential services and their importance. Conclusions: Services considered essential and important should be provided first, education and prevention should be provided more frequently than treatment, and their importance should be emphasized not only to dental hygiene students but also to dental hygienists and dentists who are the main providers of services.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.106-115
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• 2011

This study, based on (edited in 18th century), analysed the landscape system and cultural landscape elements of Yuhoidang(Hageowon 何去園) Garden in Musu-dong, Daejeon, and the findings are as in the following. YuHoidang(Gwon Yijin 權以鎭) managed Hageowon Garden in Musu-dong, located on the southern branch of Mt. Bomun, to realize his utopia. The completion of Hageowon Garden was only possible due to his installation of a variety of facilities in family gravesite on the hill behind his house: Shimyoso(Samgeunjeongsa 三近精舍, in 1707), Naboji(納汚池, in 1713), Banhwanwon(in 1714) and expended exterior space(in 1727). With regard to the landscape system of the village, the main range of mountains consists of Mt. Daedun, Mt. Odae and Mt. Bomun. The main high mountain of the three is Mt. Bomun, where 'Blue Dragon' hill branches off on the east side(Eungbong), 'White Tiger' in the west(Cheongeun and Sajeong) and Ansan(inner mountain) in the south. The landscape system is featured by 'mountains in back and rivers in front'. The river in the south-west, with its source in Mt. Juryun is called as the 'Stream of outer perfect spot', while the 'Stream of inner perfect spot' rises from Eungbong, passing through the east part of the village into the south-western direction. Banhwanwon Garden(盤桓園) was created with the stream in the east and natural bedrocks, and its landscape elements includes Naboji, Hwalsudam, Gosudae, Sumi Waterfall, Dogyeong(path of peach trees), Odeeokdae(platform with persimmon trees), Maeryong(Japanese apricot tree), springs and observatories. An expanded version of Banhwanwon was Hageowon garden, where a series of 'water-trees-stone' including streams, four ponds, five observation platforms, three bamboo forests and Chukgyeongwon(縮景園) of an artificial hill gives the origin forest a scenic atmosphere. When it comes to semantics landscape elements, there are (1) Yuhoidang to cherish the memory of a deceased parents, (2) Naboji for family unification, (3) Gosudae to keep fidelity, (4) Odeokdae to collect virtue and wisdom, (5) Sumi Waterfall to aspire to be a man of noble character, (6) Yocheondae for auspicious life, (7) Sumanheon and Gigungjae to be in pursuit of hermitic life, (8) Hwalsudam for development of family and study, (9) Mongjeong to repay favor of ancestors, (10) Seokgasan, a symbol of secluded life, (11) Hageowon to enjoy guarding graves in retired life. The spatial composition of Hageowon was realized through (1) Yuhoidang's inside gardens(Naboji, Jucheondang, Odeokdae, Dogyeong, Back yard garden and others) (2) Sumanheon(收漫軒) Byeolup or Yuhoidang's back yard gardens (Seokyeonji, Yocheondae, Sumanheon, Baegyeongdae, Amseokwon and others) (3) Chukgyeongwon of the artificial hill(which is also the east garden of Sumanheon, being composed of Hwalsudam, Sumi Waterfall and Gasan or 12 mountaintops) (4) the scenic spots for unifying Confucianism, Buddhism and Taoism are Cemetry garden in the back hill of the village, the temple of Yeogyeongam, Sansinkak(ancestral ritual place of folk religion) and Geoeopjae(family school). On top of that, Chagyeongwon Garden(借景園) commands a panoramic distant view of nature's changing beauty through the seasons.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.42-54
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• 2014

This study was conducted to identify landscaping elements such as location, situation and feng shui included in the spatiality of Jangseong Pilmaseowon and to interpret aesthetic features of visual-perceptual spatial composition according to its arrangement. As it is shown in 'Pilamseowon', 'Pilbongseowon', and 'Gimhaseoseowon' appearing in antique maps, the awareness considering 'Pilam' as 'Pilbong' and 'Gimhaseo' was revealed. Mountain Pilamsan[Mountain Munpilsan] which is the location of seowon and Pilam(Brush-shaped rock) is the core of establishment of location identity of Pilamseowon and the symbol of Haseo Kim In-hu, which shows that they are deeply related to Ingeoljiryeong(人傑地靈: 'a place derives reflected glory from an illustrious human') based on connection. Pilamseowon shows locational characteristics of living in stream(溪居) facing panoramic 'jeungsan field' without Ansan(案山). Based on the teachings of Neo-Confucianism, Village Maekdong which is the birth place of Haseo, Pilam, seowon geomancy considering the Danbonghamseo-type(丹鳳含書形) geographical shape, formative reflection, Pilmaseowon and structures revealed in building naming more clearly show symbolic landscaping features resulting from 'theory of 'Heaven-Man Unity'(天人合一)' representing the union of nature and haman, than other seowons. The maximization of centrality through connected yards constructed with the 'jeondang hujae(前堂後齋)' arrangement in the order of Whakyeon-lu, Chenogjeol-dang, Jindeak-jae or Sungui-jae, and Woodong-sa is a unique feature of spatial frame of Pilmaseowon. In addition, it reveals the centrality reinforced with 'the move of inner center through arrangement of Kyeongjang-kag and Kyesengbi inside 'YuSik(遊息)' space and religious space' and the landscaping arrangement of Pilmaseowon from installation and device for reinforcement of territoriality. Moreover, it was found that orders and aesthetic features based on Neo-Confucianism were logically realized in the formation of Pilmaseowon with visual and compositional landscaping arrangement such as 'reinforcement of view centrality through composition of windows and doors', 'securement of visual transparency through framing and duplication', and 'realization of hierarchy through height of jaesil toenmaru'. The meaning system and spatial or visual aesthetic features of Pilmaseowon newly arranged and interpreted through landscaping recomposition is not a coincidental but inevitable result. It is another resource basis and an element that can improve the internal exuberance of Pilamseowon. This landscaping reading study is expected to improve the understanding of landscapes of Pilmaseowon and elevate the sensibility of unrevealed cultural landscapes.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.4
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• pp.373-384
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• 2023

This study aims to confirm the average chronologic age according to the developmental stages of the mandibular canine (L3), first and second premolars (L4, L5), and second and third molars (L7, L8) in children and adolescents, and to confirm the developmental stage of L3, L4, L5, and L7, which can estimate the development of L8. A total of 1,956 digital panoramic radiographs of healthy individuals aged between 6 and 15 years who visited Seoul National University Dental Hospital from January 2019 to December 2020 were selected. The developmental stages of L3, L4, L5, L7, and L8 on both sides were evaluated using the dental maturity scoring system proposed by Demirjian and Goldstein. The average age at which the follicle of L8 was first observed was around 9.34 ± 1.35 years and varied from 6 to 12 years. The possibility of agenesis of L8 was high when no traces of L8 were observed after the following stages: L3, L4, and L5 at the developmental stage F and L7 at the developmental stage E; the age was about 10 years. In estimating the development of L8, when only one tooth was considered, estimation accuracy with L5 was the highest, and there was no significant difference when all four teeth were included. This study showed the age distribution according to the developmental stages of L3, L4, L5, L7, and L8 in children and adolescents and confirmed the developmental stages of L3, L4, L5, and L7, which can be used to estimate the development of L8.

• MISULJARYO - National Museum of Korea Art Journal
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• v.96
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• pp.89-122
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• 2019

In this paper, I argue that the Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers by Jeong Su-yeong (1743~1831, pseudonym: Jiwujae) is a record of his private journeys to several places on the outskirts of Hanyang (present-day Seoul) and that it successfully embodies the painter's subjective perspective while boating on these rivers and going on outings to nearby mountains. Around 1796, Jeong Su-yeong traveled to different places and documented his travels in this 16-meter-long handscroll. Several leaves of paper, each of which depicts a separate landscape, are pieced together to create this long handscroll. This indicates that the Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers reflected the painter's personal subjective experiences as he went along his journey rather than simply depicts travel destinations. The Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers features two types of travel: boating and mountain outings on foot. Traveling by boat takes up a large portion of the handscroll, which illustrates the channels of the Hangang and Imjingang Rivers. Mountain outings correspond to the sections describing the regions around Bukhansan, Gwanaksan, and Dobongsan Mountains. Jeong Su-yeong traveled to this wide span of places not just once, but several times. The fact that the Hangang River system are not presented in accordance with their actual locations shows that they were illustrated at different points. After visiting the riversides of the Hangang and Namhangang Rivers twice, Jeong Su-yeong delineated them in fourteen scenes. Among them, the first eight illustrate Jeong's initial trip by boat, while the other six scenes are vistas from his second trip. These fourteen scenes occupy half of this handscroll, indicating that the regions near the Hangang River are painted most frequently. The scenes of Jeong Su-yeong's first boating trip to the system of the Hangang River portray the landscapes that he personally witnessed rather than famous scenes. Some of the eight scenic views of Yeoju, including Yongmunsan Mountain, Cheongsimru Pavilion, and Silleuksa Temple, are included in this handscroll. However, Jeong noted spots that were not often painted and depicted them using an eye-level perspective uncommon for illustrating famous scenic locations. The scenes of Jeong's second boating trip include his friend's villa and a meeting with companions. Moreover, Cheongsimru Pavilion and Silleuksa Temple, which are depicted in the first boating trip, are illustrated again from different perspectives and in unique compositions. Jeong Su-yeong examined the same locations several times from different angles. A sense of realism is demonstrated in the scenes of Jeong's first and second boating trips to the channels of the Hangang River, which depict actual roads. Furthermore, viewers can easily follow the level gaze of Jeong from the boat. The scenes depicting the Imjingang River begin from spots near the Yeongpyeongcheon and Hantangang Rivers and end with places along the waterways of the Imjingang River. Here, diverse perspectives were applied, which is characteristic of Imjingang River scenes. Jeong Su-yeong employed a bird's-eye perspective to illustrate the flow of a waterway starting from the Yeongpyeongcheon River. He also used an eye-level perspective to highlight the rocks of Baegundam Pool. Thus, depending on what he wished to emphasize, Jeong applied different perspectives. Hwajeogyeon Pond located by the Hantangang River is illustrated from a bird's-eye perspective to present a panoramic view of the surroundings and rocks. Similarly, the scenery around Uhwajeong Pavilion by the Imjingang River are depicted from the same perspective. A worm's-eye view was selected for Samseongdae Cliff in Tosangun in the upper regions of the Imjingang River and for Nakhwaam Rock. The scenes of Jeong Su-yeong's mountain outings include pavilions and small temple mainly. In the case of Jaeganjeong Pavilion on Bukhansan Mountain, its actual location remains unidentified since the pavilion did not lead to the route of the boating trip to the system of the Hangang River and was separately depicted from other trips to the mountains. I speculate that Jaeganjeong Pavilion refers to a pavilion either in one of the nine valleys in Wooyi-dong at the foot of Bukhansan Mountain or in Songajang Villa. Since these two pavilions are situated in the valleys of Bukhansan Mountain, their descriptions in written texts are similar. As for Gwanaksan Mountain, Chwihyangjeong and Ilganjeong Pavilions as well as Geomjisan Mountain in the Bukhansan Mountain range are depicted. Ilganjeong Pavilion was a well-known site on Gwanaksan that belonged to Shin Wi. In this handscroll, however, Jeong Su-yeong recorded objective geographic information on the pavilion rather than relating it to Shin Wi. "Chwihyangjeong Pavilion" is presented within the walls, while "Geomjisan Mountain" is illustrated outside the walls. Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers also includes two small temples, Mangwolam and Okcheonam, on Dobongsan Mountain. The actual locations of these are unknown today. Nevertheless, Gungojip (Anthology of Gungo) by Yim Cheonsang relates that they were sited on Dobongsan Mountain. Compared to other painters who stressed Dobong Seowon (a private Confucian academy) and Manjangbong Peak when depicting Dobongsan Mountain, Jeong Su-yeong highlighted these two small temples. Jeong placed Yeongsanjeon Hall and Cheonbong Stele in "Mangwolam small temple" and Daeungjeon Hall in front of "Okcheonam small temple." In addition to the buildings of the small temple, Jeong drew the peaks of Dobongsan Mountain without inscribing their names, which indicates that he intended the Dobongsan peaks as a background for the scenery. The Handscroll of a Sightseeing Trip to the Hangang and Imjingang Rivers is of great significance in that it embodies Jeong Su-yeong's personal perceptions of scenic spots on the outskirts of Hanyang and records his trips to these places.