• 대한치과교정학회지
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• 제53권2호
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• pp.77-88
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• 2023

Objective: To develop a method for generating three-dimensional (3D) digital models of the periodontal ligament (PDL) using 3D cone-beam computed tomography (CBCT) reconstruction and to evaluate the accuracy and agreement of the 3D PDL models in the measurement of periodontal bone loss. Methods: CBCT data collected from four patients with skeletal Class III malocclusion prior to periodontal surgery were reconstructed at three voxel sizes (0.2 mm, 0.25 mm, and 0.3 mm), and 3D tooth and alveolar bone models were generated to obtain digital PDL models for the maxillary and mandibular anterior teeth. Linear measurements of the alveolar bone crest obtained during periodontal surgery were compared with the digital measurements for assessment of the accuracy of the digital models. The agreement and reliability of the digital PDL models were analyzed using intra- and interexaminer correlation coefficients and Bland-Altman plots. Results: Digital models of the maxillary and mandibular anterior teeth, PDL, and alveolar bone of the four patients were successfully established. Relative to the intraoperative measurements, linear measurements obtained from the 3D digital models were accurate, and there were no significant differences among different voxel sizes at different sites. High diagnostic coincidence rates were found for the maxillary anterior teeth. The digital models showed high intra- and interexaminer agreement. Conclusions: Digital PDL models generated by 3D CBCT reconstruction can provide accurate and useful information regarding the alveolar crest morphology and facilitate reproducible measurements. This could assist clinicians in the evaluation of periodontal prognosis and establishment of an appropriate orthodontic treatment plan.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권3호
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• pp.230-234
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• 2006

Purpose: This study presents radiographic and laboratory analysis and comparison of bone resorption rate of grafted endochondral bone and intramembranous bone on the aspect of height and volumetric change. Patients and Methods: 18 partially edentulous patients who needed alveolar ridge augmentation for implant placement during the years 2002 to 2004 were selected for this study. Group A consisted of 5 males & 3 females who were treated with intraoral(intramembranous) bone and Group B consisted of 8 males & 2 females who were treated with iliac(endochondral) bone. Non-standard periapical X-ray was taken at day 1, 2 month, 4 months, 8 months after the surgery. Resorption rate of grafted bone were measured on these X-rays and compared. Also we calculated volume of grafted bone with models which was fabricated at 1.5 months, 6 months. Results: There was bone resorption in both groups. Group B showed more bone resorption than Group A. In Group A, the resorption rate according to the radiographic measurements was 9.81 %, and resorption rate according to volumetric measurement was 16.5 %. In group B, the resorption rate according to the radiographic measurements was 15.9 %, and resorption rate according to volumetric measurement was 30.6 %. Significant difference is on radiographic resorption of post-op 2, 4, 8 months on two groups (P < 0.05). Also significant difference is on volume resorption on two groups (P < 0.05). Conclusion: We found that more bone resorption occurred with iliac(endochondral) bone and when we use intraoral bone, that bone can maintain their vitality for alveolar ridge augmentation.

• 한국방사선학회논문지
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• 제11권1호
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• pp.43-48
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• 2017

최근 동위원소를 이용한 뼈 스캔 (Bone Scan)검사 후 골밀도 (BMD; Bone Mineral Density)검사를 당일검사로 병행한 경우 이로 인한 골밀도 측정값에 오차 발생 가능성이 제기되고 있으나 방사성의약품 표지화합물 투여 후 이중에너지 X선을 이용한 골밀도 측정값 변화에 대한 임상적 자료가 미비하여 핵의학 체내검사 후 당일 골다공증 검사의 측정값에 대한 논란의 소지가 있다. 따라서 동위원소 표지화합물인 $^{99m}Tc-MDP$가 골밀도 측정값에 영향을 미치는지 임상적 측면에서 실험하였다. 실험에 참가한 대상자의 평균 나이는 $35.17{\pm}9.45$세로 실험 대상자 17명 중 대사성 질환과 골밀도 측정에 영향을 줄 수 있는 허리뼈 압박골절 및 몸쪽 넓적다리뼈 골절이 있는 자를 제외한 12명 중 정상 골밀도 T-scores>-1.0의 환자 6명을 대상으로 $^{99m}Tc-MDP$ 투여 전 후 측정값을 분석한 결과 허리뼈에서 전 후 각각 평균 $0.975{\pm}0.084g/cm^2$, $0.966{\pm}0.078g/cm^2$으로 $0.009g/cm^2$ 증가, 우측 몸쪽 넓적다리뼈에서는 전 후 각각 평균 $0.909{\pm}0.078g/cm^2$, $0.913{\pm}0.086g/cm^2$으로 $0.004g/cm^2$ 감소, 좌측 몸쪽 넓적다리뼈에서는 각각 평균 $0.887{\pm}0.099g/cm^2$, $0.881{\pm}0.103g/cm^2$으로 $0.007g/cm^2$의 증가를 보여 몸쪽 넓적다리뼈 보다 허리뼈에서 더 큰 골밀도 변화를 보여주었다. 그러나 허리뼈와 몸쪽 넓적다리뼈 전체에서 전 후 변화 평균은 $0.0038{\pm}0.014g/cm^2$으로 골밀도 측정값에 유의한 영향이 없음을 알 수 있으며, 또한 두 실험간 전체 상관계수는 0.987으로 방사성동위원소 표지화합물인 $^{99m}Tc-MDP$ 투여가 골밀도 측정값에 영향을 주지 않았다. 따라서 140 keV의 감마선 에너지를 방출하는 테크네슘 표지화합물을 이용한 뼈 스캔검사 후 골밀도 측정값에 유의한 영향을 미치지 않음을 확인하였다. 그러나 핵의학적 체내검사와 골다공증 검사를 당일로 검사함으로 인한 환자의 피폭을 고려한다면 시간 간격을 두고 검사를 시행하는 것이 좋을 것으로 사료된다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 2004년도 추계학술발표대회논문집 제23권 2호
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• pp.183-186
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• 2004

Biot's theory and a modified Biot-Attenborough (MBA) model are applied to predict the dependences of acoustic characteristics on frequency and porosity in cancellous bone. The phase velocity and the attenuation coefficient predicted by both theories are compared with previous in vitro experimental measurements in terms of the mixed, the fast, and the slow waves. Biot's theory successfully predicts the dependences of phase velocity on frequency and porosity in cancellous bone, whereas a significant discrepancy is observed between predicted and measured attenuation coefficients. The MBA model is consistent with reported measurements for both dependences of phase velocity and attenuation coefficient on frequency and porosity. Based on the theoretical predictions from the MBA model, it is suggested that the attenuation coefficient of the mixed wave is dominated by the fast wave in the low-porosity region while it is dominated by the slow wave in the high-porosity region. This provides a qualitative explanation for the nonlinear relationship of attenuation of the mixed wave with porosity in cancellous bone.

• Imaging Science in Dentistry
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• 제43권2호
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• pp.85-90
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• 2013

Purpose: This study was performed to determine the buccal alveolar bone thickness following rapid maxillary expansion (RME) using cone-beam computed tomography (CBCT). Materials and Methods: Twenty-four individuals (15 females, 9 males; 13.9 years) that underwent RME therapy were included. Each patient had CBCT images available before (T1), after (T2), and 2 to 3 years after (T3) maxillary expansion therapy. Coronal multiplanar reconstruction images were used to measure the linear transverse dimensions, inclinations of teeth, and thickness of the buccal alveolar bone. One-way ANOVA analysis was used to compare the changes between the three times of imaging. Pairwise comparisons were made with the Bonferroni method. The level of significance was established at p<0.05. Results: The mean changes between the points in time yielded significant differences for both molar and premolar transverse measurements between T1 and T2 (p<0.05) and between T1 and T3 (p<0.05). When evaluating the effect of maxillary expansion on the amount of buccal alveolar bone, a decrease between T1 and T2 and an increase between T2 and T3 were found in the buccal bone thickness of both the maxillary first premolars and maxillary first molars. However, these changes were not significant. Similar changes were observed for the angular measurements. Conclusion: RME resulted in non-significant reduction of buccal bone between T1 and T2. These changes were reversible in the long-term with no evident deleterious effects on the alveolar buccal bone.

• 대한치과교정학회지
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• 제32권5호
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• pp.361-373
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• 2002

이번 연구의 목적은 골격성 III급 부정교합자의 악교정 수술 전과 수술 후의 하악전치부 치조골의 형태 변화를 평가하는 것이다 : 하악지 시상골분할절단술만을 시행받은 30명의 성인 골격성 III급 부정교합자를 대상으로 하였다. 초진시와 수술 전과 수술 후 3개월이 경과하였을 때의 측모두부규격방사선 사진을 비교하였다 골격과 하악이부의 계측치를 비교하였으며 이들 사이의 상관성 분석을 시행하여서 다음과 같은 결과를 얻었다. 1. 술전교정후군과 악교정수술후군에서 치료전군에 비해 하악전치부의 순측과 설측의 치조골 높이가 감소하였다. 2. 치조골 기저부의 전후방적인 폭경은 두개안면골격의 수직계측항목과 역상관관계를, IMPA와는 순상관관계를 보였다(P<0.01). 3. 하악이부 계측항목중 하악이부의 장경과 폭경은 두개안면골격과 상관관계를 보이지 않았다. 4. 순측의 치조골 높이와 설측의 치조골 높이는 순상관관계를 나타냈지만(p<0.001), 설측의 치조정의 폭경과는 역상관관계를 보였다(p<0.01). 순측과 설측의 치조정의 폭경은 역상관관계를 보였다(p<0.05). 하악이부의 장경과 폭경은 서로 순상관관계를 보였다(p<0.01). 5. IMPA와 LISA는 순, 설측치조골의 장경과 설측의 치조골 폭경과는 역상관관계를 보였지만, 순측치조골폭경과는 순상관관계를 보였다

• 대한한방소아과학회지
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• 제22권2호
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• pp.69-80
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• 2008

Objectives : The purpose of this study was to evaluate the correlation of 3 methods of bone age measurements. Methods : 102 children(49 boys, 53 girls) were involved in this study. We measured the height, weight and bone age based when they visited for the first time. We measured bone age using BoneAge of Sunlight Co.,Ltd. Two of the bone age measurement methods, Greulich-Pyle and Tanner-Whitehouse, were used to analyze the left dorsopalmar hand-wrist radiographs of 102 children who visited in Department of Pediatrics, O O University Oriental Hospital. This study was designed to investigate the correlation of the bone age between two methods. Results : The bone ages were related with age, height, weight and BMI according to this study(P<0.01). Each bone age assessment method had statistically significant correlation to each other(P<0.01). Conclusions : The ultrasound transonic velocity of inferior radiocarpal joint will become a sufficient diagnostic tool of bone age assessment if measurement error can be minimized by proper effort.

• Imaging Science in Dentistry
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• 제52권4호
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• pp.375-382
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• 2022

Purpose: The aim of this study was to analyze the relationships between bone density measurements obtained using cone-beam computed tomography (CBCT) and morphometric parameters of bone determined by histomorphometric analysis. Materials and Methods: In this in vivo study, 30 samples from the maxillary bones of 7 sheep were acquired using a trephine. The bone samples were returned to their original sites, and the sheep heads were imaged using CBCT. On the CBCT images, gray values were calculated. In the histomorphometric analysis, the total bone volume, the trabecular bone volume (referred to simply as bone volume), and the trabecular thickness were assessed. Results: Statistical testing showed significant correlations between CBCT gray values and total bone volume (r =0.537, P =0.002), bone volume (r =0.672, P<0.001), and trabecular thickness (r =0.692, P<0.001), as determined via the histomorphometric analysis. Conclusion: The results indicate a significant and acceptable association between CBCT gray values and bone volume, suggesting that CBCT may be used in bone densitometry.

• Imaging Science in Dentistry
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• 제34권3호
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• pp.159-164
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• 2004

Purpose: To compare alveolar bony height of pantomograph with bony height of thin slice, multiplanar reformatted (MPR) Computed Tomograph. Materials and Methods : Panoramic radiograms of 12 young adult patients had been taken by one radologic technitian and the measurements were corrected by magnification ratio (1.20). The slice thickness of Multi-detector Computed Tomography (CT) was at least 1mm for the accuracy. The raw CT datas were imported into the V-works 4.0 (CyberMed Corp., Seoul, Korea) and transformed to MPR images. Pantomographic measurements of alveolar bone were compared to CT values by average mean bony height measurements for the accuracy. Inter-, and Intra-observer variability was evaluated. Results : There was no significant differences between height measurement of pantomography and that of CT (P>0.05). There were no significant differences in either inter-or intra-observer measurements (P>0.05). Conclusion : Pantomography showed relatively high accuracy and precision in measuring alveolar bony height.

• Journal of Nutrition and Health
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• 제40권1호
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• pp.69-77
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• 2007

The study was conducted to investigate the factors associated with bone mineral content (BMC) changes among early pubertal aged girls. Two hundred and thirty girls between 9 to 11 years of age participated in (our surveys over 2 year period. During each survey, dietary intakes were collected with 3-day food records, BMC of left leg's calcaneus were measured by PIXI (Lunar Ltd.) and body composition was measured by bioimpedance method (Inbody 3.0 Biospace Co. Ltd, Seoul, Korea). Mean values of BMC increased in consecutive measurements -1.48 g, 1.54 g, 1.61 g and 1.66 g. The change of BMC between the first and last measurements was significantly positively correlated with % body fat, negatively correlated with BMC at the baseline (p < 0.05). Change of BMC was also significantly positively correlated with % change of lean mass and mineral mass between the first and last measurements. Nutrient intakes during the study period were calculated as mean daily intakes from all surveys. Mean daily intakes of Vit. C and Vit. $B_6$ were positively and isoflavone intake was negatively correlated with changes of BMC (p < 0.05). In stepwise regression of BMC change with body composition and nutrient intakes, baseline values of BMC, weight, BMI and age, % change of mineral mass during the study period, mean intakes of isoflavone, Vit. $B_6$, protein, carotene and zinc were significant explanatory variables ($R^2=0.38$, p <.001, F = 32.39). The results imply that the change of BMC among early pubertal aged girls are associated with some body composition and intakes of certain nutrients.