변연융선평면을 계측기준으로 한 정상교합자의 구치부 치관경사도에 관한 연구

임성훈,윤영주,김광원 대한치과교정학회 1998 대한치과교정학회지 Vol.28 No.5

이전의 preadjusted appliance 개발을 위한 치관경사도의 계측에 있어서는 교합평면을 계측기준으로 사용했는데, 교합평면은 Spee 만곡으로 인해 브라켓 부착점들을 연결하는 선(Andrews' plane)에 평행하지 않은 문제점이 있었다. 따라서 본 연구에서는 Spee 만곡에 영향받지 않으며, Andrews' plane에 보다 평행한 계측기준으로 각각의 구치의 근, 원심측 변연융선을 잇는 가상선을 설정하고, 이를 변영융선평면으로 명명하였다. 교합평면과 변연융선평면으로부터 각각 정상교합자의 구치부 치관경사도를 계측하여 비교한 결과 교합평면을 기준으로 한 치관경사도가 특히 상, 하악 제 1소구치(P<0.05) 및 제 2대구치(P<0.01)에서 Spee 만곡의 영향을 받음을 발견하였다. 구치부 치아들의 치관경사도는 Spee 만곡의 양에 따라 변해야만 인접치간 변연융선의 불일치가 생기지 않는다. 이전의 연구들에서는 다소의 Spee 만곡을 갖는 정상교합자 표본에서 교합평면을 기준으로 계측한 치관경사도를 Spee 만곡이 없는 교합평면이 치료 목표의 일부인 bracket system에 적용하는 오류가 있었다. 이러한 치관경사도와 Spee 만곡 사이의 부조화는 Spee 만곡이 straight wire에 의해 완전히 leveling되었을 때 변연융선 불일치를 초래할 수 있다. 이를 해결하기 위해서는 구치부 브라켓 slot이 변연융선평면에 평행하도록 브라켓 경사도를 결정하는 것이 추천된다. In the previous studies about prescription of preadjusted appliance, occlusal plane was used as a reference plane for crown angulation (tip) measurement. But this reference plane is not parallel to the line connecting the facial axis points at which the centers of brackets are positioned (Andrews' plane), due to the curve of Spee. Therefore, we developed a new reference plane unaffected by the curve of Spee and more parallel to the Andrew's plane. It is an imaginary line connecting mesial and distal marginal ridges of each posterior tooth, and we named it 'marginal ridge plane'. In this study, crown angulations of posterior teeth or 29 normal occlusion samples were measured and measurements from both reference planes were compared. Crown angulation measurements measured from occlusal plane were different from crown angulation measurements from marginal ridge plane in the upper and lower 2nd molars (p<0.01), and 1st premolars (p<0.05). These results were analyzed as the crown angulation measurements from occusal plane were affected by the curve of Spee. Crown angulations should be varied according to the amount of curve of Spee to maintain the continuity of marginal ridges. To solve this problem, determining bracket angulation as the bracket slot is parallel to the marginal ridge plane of each posterior teeth is recommended.

Drilling Gas Hydrate at Hydrate Ridge, ODP Leg 204

이영주(Lee, Young-Joo),류병재(Ryu, Byong-Jae),김지훈(Kim, Ji-Hoon),이상일(Lee, Sang-Il) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

Gas hydrates are ice-like compounds that form at the low temperature and high pressure conditions common in shallow marine sediments at water depths greater than 300-500 m when concentrations of methane and other hydrocarbon gases exceed saturation. Estimates of the total mass of methane carbon that resides in this reservoir vary widely. While there is general agreement that gas hydrate is a significant component of the global near-surface carbon budget, there is considerable controversy about whether it has the potential to be a major source of fossil fuel in the future and whether periods of global climate change in the past can be attributed to destabilization of this reservoir. Also essentially unknown is the interaction between gas hydrate and the subsurface biosphere. ODP Leg 204 was designed to address these questions by determining the distribution, amount and rate of formation of gas hydrate within an accretionary ridge and adjacent basin and the sources of gas for forming hydrate. Additional objectives included identification of geologic proxies for past gas hydrate occurrence and calibration of remote sensing techniques to quantify the in situ amount of gas hydrate that can be used to improve estimates where no boreholes exist. Leg 204 also provided an opportunity to test several new techniques for sampling, preserving and measuring gas hydrates. During ODP Leg 204, nine sites were drilled and cored on southern Hydrate Ridge, a topographic high in the accretionary complex of the Cascadia subduction zone, located approximately 80km west of Newport, Oregon. Previous studies of southern Hydrate Ridge had documented the presence of seafloor gas vents, outcrops of massive gas hydrate, and a pinnacle' of authigenic carbonate near the summit. Deep-towed sidescan data show an approximately 300times500m area of relatively high acoustic backscatter that indicates the extent of seafloor venting. Elsewhere on southern Hydrate Ridge, the seafloor is covered with low reflectivity sediment, but the presence of a regional bottom-simulating seismic reflection (BSR) suggests that gas hydrate is widespread. The sites that were drilled and cored during ODP Leg 204 can be grouped into three end-member environments basedon the seismic data. Sites 1244 through 1247 characterize the flanks of southern Hydrate Ridge. Sites 1248-1250 characterize the summit in the region of active seafloor venting. Sites 1251 and 1252 characterize the slope basin east of Hydrate Ridge, which is a region of rapid sedimentation, in contrast to the erosional environment of Hydrate Ridge. Site 1252 was located on the flank of a secondary anticline and is the only site where no BSR is observed.

Spreading ridge-trench interaction on the continental margin around Anvers Island, Antarctic Peninsula

진영근(Young Keun Jin),홍종국(Jong Kuk Hong) 대한지질학회 2007 지질학회지 Vol.43 No.4

위축된 상악구치부에서 두 개의 짧은 임플란트 지지형 단일치관의 임상연구

송호용(Ho-Yong Song),허윤혁(Yoon-Hyuk Heo),박찬진(Chan-Jin Park),조리라(Lee-Ra Cho) 대한치과의사협회 2015 대한치과의사협회지 Vol.53 No.9

Purpose: The aim of this retrospective study was to compare marginal bone loss and survival rates of double short implants(multiple implant) which had been installed and restored in severely atrophic maxillary molar site without a grafting procedure. Material and Method: The subjects were patients (90 patients, 180 implants) who had been installed double short implants in severely atrophic maxillary single molar site without bone augmentation procedure from 2006 to 2014 in dental clinic in Chuncheon city. Following data were collected from dental records and radiographic panoramic views: patient’s age, gender, smoking status, implant site, timing of implant installation, residual ridge height. The correlation between those factors and survival rate and marginal bone loss were analyzed. Statistical analysis was performed using Chi-square test, Student’s t- test and ANOVA. Result: Eleven implants in 6 patients failed and the cumulative survival rate was 93.9%. No significant differences were found in relation to the following factors: patient’s age, gender, implant site, timing of implant installation (P> .05). There were significant differences in smoking status and residual ridge height(P< .05). The average follow-up time was 45 ± 14.7 months. The mean marginal bone loss of survived 169 implants was 0.08 ± 0.59 mm. Conclusion: Despite the short term outcomes, the survival rate of double short implants was comparable to normal length implants. This study demonstrated that placement of double short implants without the use of bone grafting procedure for severely atrophic posterior maxilla is a simple and predictable treatment procedure.

유 · 소아 부비강 Water's 영상의 이상적 구현을 위한 촬영기준각도 변화에 관한 연구

손상혁,김제봉,송영근,홍상우,김성규 대한방사선과학회 2007 방사선기술과학 Vol.30 No.2

This study is to calculate the proper angle for the optimal image of PNS Water's view on children, comparing and analyzing the PNS Water's projection angles between children and adults at every age. This study randomly selected 50 patients who visited the Medical Center from January to May in 2005, and examined the incidence path of central ray, taking a PNS Water's and skull trans-Lat. view in Water's filming position while attaching a lead ball mark on the Orbit, EAM, and acanthion of the patients's skull. And then, we calculated the incidence angles(Angle A) of the line connected from OML and the petrous ridge to the inferior margin of maxilla on general(random) patients's skull image, following the incidence path of central ray. Finally, we analyzed two pieces of the graphs at ages, developing out the patients' ideal images at PNS Water's filming position taken by a digital camera, and calculating the angle(Angle B) between OML and IP(Image Plate). The angle between OML and IP is about 43° in 4-years-old children, which is higher than 37°, as age increases the angle decreases, it goes to 37° around 30 years of age. That is similar result to maxillary growth period. We can get better quality of Water's image for children when taking the PNS Water's view if we change the projection angles, considering maxillary growth for patients in every age stage.

유ㆍ소아 부비강 Water"s 영상의 이상적 구현을 위한 촬영기준각도 변화에 관한 연구

손상혁(Sang-Hyuk Son),송영근(Young-Geun Song),홍상우(Sung-Kyu Kim),김성규(Sang-Woo Hong),김제봉(Je-Bong Kim) 대한방사선과학회(구 대한방사선기술학회) 2007 방사선기술과학 Vol.30 No.2

  상악동은 연령이 증가함에 따라 크기와 형태가 변화하고. 추체부와의 해부학적 상관관계도 변화된다. 유소아의 연령대별 상악동과 추체부의 상관관계 변화에 따른 촬영 기준 각도(OML과 IP가 이루는 각도)를 산출함으로서 PNS Water"s 영상의 이상적 구현을 위한 촬영 기준 각도를 제시하고자 한다.<BR>  본원 내원 환자 50명을 대상으로 두개부에 납볼을 붙이고, PNS Water"s 촬영 자세에서 X-선 발생장치와 디지털카메라를 동시에 이용하여 PNS Water"s 및 Skull trans-Lat.의 X-선 촬영을 실시하고 PNS Water"s 촬영자세에서 일반사진 측면상을 촬영한 후, 방사선 영상을 이용 중심선속의 입사 경로와 OML과 상악동 하연에서 추체부를 연결하는 선의 각도(Angle A)를 산출하여 90°-Angle A의 그래프를 얻고, 일반사진 측면상에서는 이상적인 Water"s 영상으로 평가된 환자의 OML과 Image Plate(IP)가 이루는 각도(Angle B)를 산출하여 연령에 따른 그래프를 작성한 후, 두 개의 그래프를 비교 분석하였다.<BR>  분석 결과 OML과 Image Plate(IP)가 이루는 각도(Angle B)는 4세 소아에서는 평균 43°로 마호니가 제시한 기준각도인 37° 보다 크게 나타났으며, 연령이 증가함에 따라 각도가 감소하여, 만 30세 부터는 37°에 근접하는 결과를 얻을 수 있었다.<BR>  PNS Water"s 검사에서 상악동의 성장을 고려하여 연령별 OML과 Image Plate(IP)가 이루는 각도에 변화를 주어 촬영한다면, 유 소아 발생하기 쉬운 상악동의 왜곡을 최소화하여 보다 정확한 검사가 가능할 것으로 사료된다.   This study is to calculate the proper angle for the optimal image of PNS Water"s view on children, comparing and analyzing the PNS Water"s projection angles between children and adults at every age.<BR>  This study randomly selected 50 patients who visited the Medical Center from January to May in 2005, and examined the incidence path of central ray, taking a PNS Water"s and skull trans-Lat. view in Water"s filming position while attaching a lead ball mark on the Orbit, EAM, and acanthion of the patients"s skull. And then, we calculated the incidence angles(Angle A) of the line connected from OML and the petrous ridge to the inferior margin of maxilla on general(random) patients"s skull image, following the incidence path of central ray.<BR>  Finally, we analyzed two pieces of the graphs at ages, developing out the patients" ideal images at PNS Water"s filming position taken by a digital camera, and calculating the angle(Angle B) between OML and IP(Image Plate).<BR>  The angle between OML and IP is about 43° in 4-years-old children, which is higher than 37°, as age increases the angle decreases, it goes to 37° around 30 years of age. That is similar result to maxillary growth period.<BR>  We can get better quality of Water"s image for children when taking the PNS Water"s view if we change the projection angles, considering maxillary growth for patients in every age stage.