• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권4호
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• pp.353-359
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• 1999

Purpose : A new method of lateral cephalometric analysis for midface, focusing on zygomatic bone, was created in this study, and measured in Korean adults. The purposes of this study are understanding about new approach for midfacial depression, especially zygomatic bone, and using to make adequate diagnosis and treatment plan. Materials and methods : In this study, esthetic Korean adults, 25 males and 25 females who were between $0^{\circ}$ and $4^{\circ}$ in ${\angle}ANB$, and between 62% and 70% in P/A facial height ratio, and had normal overbite and overjet, were used. Orbitale(Or) and Soft tissue orbitale(Or') were used for indicators of anteroposterior position of zygomatic area. And, mean value and standard deviation of linear and angular measurements, and ratio about each linear measurements, were obtained. then, standard deviation diagram - wiggle diagram - was made for visualization of results. Results : Mean values, standard deviations and ranges of 19 measurements were obtained, and among them, 5 linear measurements that had large standard deviation were excluded and the others were used for making standard deviation diagram. In standard deviation diagram, the following results were obtained. 1. If the measurements are located on more left side of mean-value-vertical -line, the potential of midfacial hypoplasia are stronger, especially zygomatic area. 2. If the measurements are located on more right side of mean-value-vertical-line, the potential of midfacial hypoplasia are decreased. Conclusion : This study presented a new method of lateral cephalometric analysis focusing on zygomatic bone in Korean adults. We expect that the results of this study can be used as parameter when clinicians make decisions about diagnosis and treatment plan for rehabilitation of esthetics and function. But, it is necessary to prove its usefulness, and to further evaluate the results.

• 대한치과교정학회지
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• 제16권2호
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• pp.99-106
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• 1986

The author studied 21 adenoid hypertrophied children and 50 normal children by the horizontal, vertical and angular measurements to analyze, the effects of the lymphadenoid hypertrophy to the tongue, mandible, and hyoid bone position. The results were as follows; 1. The tongue of the Adenoid hypertrophy children was positioned mon anterior and lower than that of the normal children. 2. The horizontal, vertical, and angular measurements of the mandible position were larger in the experimental group and especially ANS to ME, PNS to MP, PTM to MP, PP to MP, FOP to MP showed statistically significant difference. 3. The measurements of the hyoid bone position were also larger in the experimental group.

• Clinics in Shoulder and Elbow
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• 제23권3호
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• pp.119-124
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• 2020

Background: This study was performed to compare glenoid version and inclination measured using two-dimensional (2D) images from computed tomography (CT) scans or three-dimensional (3D) reconstructed bone models. Methods: Thirty patients who had undergone conventional CT scans were included. Two orthopedic surgeons measured glenoid version and inclination three times on 2D images from CT scans (2D measurement), and two other orthopedic surgeons performed the same measurements using 3D reconstructed bone models (3D measurement). The 3D-reconstructed bone models were acquired and measured with Mimics and 3-Matics (Materialise). Results: Mean glenoid version and inclination in 2D measurements were -1.705° and 9.08°, respectively, while those in 3D measurements were 2.635° and 7.23°. The intra-observer reliability in 2D measurements was 0.605 and 0.698, respectively, while that in 3D measurements was 0.883 and 0.892. The inter-observer reliability in 2D measurements was 0.456 and 0.374, respectively, while that in 3D measurements was 0.853 and 0.845. Conclusions: The difference between 2D and 3D measurements is not due to differences in image data but to the use of different tools. However, more consistent results were obtained in 3D measurement. Therefore, 3D measurement can be a good alternative for measuring glenoid version and inclination.

• Journal of Periodontal and Implant Science
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• 제48권4호
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• pp.202-212
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• 2018

Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

• 대한지역사회영양학회지
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• 제28권4호
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• pp.282-292
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• 2023

Objectives: Bone health in early adulthood, as individuals approach peak bone mass, plays a critical role in preventing osteoporosis later in life. This study aimed to investigate the associations between lifestyle and dietary factors, anthropometric measurements, and urinary bone resorption markers in young adults. Methods: A cross-sectional study was conducted with 100 healthy Korean adults (50 men and 50 women) in their 20s and early 30s. Bone mineral density (BMD), anthropometric measurements, dietary intake (24-hour recall), and urinary bone resorption indicators (deoxypyridinoline and N-terminal telopeptide of type I collagen) were analyzed. Variables were compared between the osteopenia and osteoporosis groups (OSTEO group: 30% men and 60% women) and the healthy control group. Results: Men in the OSTEO group were significantly taller than those in the control group (P < 0.05). Women in the OSTEO group had significantly lower body weight and body composition (muscle and body fat) than those in the normal group (P < 0.01). Men in the OSTEO group had a significantly higher intake of animal calcium (Ca) than those in the normal group (P < 0.05). Women in the OSTEO group had significantly higher dietary fiber, vitamin A, Ca, plant Ca, and potassium intake than did those in the normal group (P < 0.05). There were no significant differences in caffeinated beverage consumption, eating habits, or urinary bone resorption indicators between the OSTEO and control groups of either sex. Conclusions: In our study of young South Korean adults, we observed low bone density levels, with particularly low BMD in taller men and underweight women. We found a higher nutrient intake in the OSTEO group, indicating the possibility of reverse causality, a phenomenon often found in cross-sectional studies. Therefore, there is a need to further elucidate dietary factors related to osteoporosis in young adults through prospective cohort studies involving a larger population.

• 대한치과교정학회지
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• 제53권4호
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• pp.264-275
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• 2023

Objective: To investigate the effects of maxillary orthodontic expansion on the alveolar bone tissue in adult patients treated with aligners by using cone-beam computed tomography. Methods: Thirty patients (22 females and 8 males; mean age: 36.3 years) were treated with Invisalign^® aligners. Cone-beam computed tomography and digital models were obtained before (T0) and after (T1) upper arch expansion. The bone thicknesses in the cervical, middle, and apical areas of the incisors, canines, premolar, and first molars were buccally and palatally measured, totaling 96 areas and 2,880 measurements. The buccolingual inclinations and transverse measurements of the teeth were obtained from digital models to correlate them with the bone changes. The statistical tests used were Student's t-test, analysis of variance, and Pearson's correlation tests (p < 0.05). Results: From the 96 areas evaluated, 84 revealed an increase or stability in the alveolar bone thickness and twelve displayed significant bone loss. Bone changes did not correlate with the tooth inclination and transverse measurements. Conclusions: Within the limitation of the present study, mild levels of upper arch expansion obtained with Invisalign^® aligners in adult patients did not result in any clinically significant loss of alveolar bone thickness.

• Journal of Nutrition and Health
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• 제37권1호
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• pp.52-60
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• 2004

This study was conducted to investigate the bone mineral density (BMD) and the anthropometric measurements, socioeconomic factors, family history of osteoporosis and other environmental factors affecting BMD in children. One hundred sixty children (80 males, 80 females) in second grade of elementary school in Seoul were recruited; the mean age was 7.7 $\pm$ 0.47 years. Bone mineral density was measured in the lumbar spine (LS), femoral neck (FN), femoral trochanter (FT), and Ward's triangle (WT) by Dual Energy X-ray Absorptiometry (DEXA). Socioeconomic factors, family history of osteoporosis, and other environmental factors were assessed by questionnaire. Bone mineral densities of LS, FN, FT, and WT were 0.677, 0.637, 0.618, and 0.658 g/$\textrm{cm}^2$. BMD of boys was higher than that of girls (LS: 0.685 vs. 0.669, FN: 0.660 vs. 0.614, FT: 0.632 vs. 0.604, WT: 0.678 vs. 0.639 g/$\textrm{cm}^2$). Anthrometric measurements (height, weight relative body weight, circumference of waist and hip) were positively correlated with BMD. With increasing family income, BMD of LS was significantly lowered, and negative correlation was observed between mother's age at birth of subject and the BMD of FN. And the BMD of children with a family history of osteoporosis was significantly lower. However BMDs were not different by educational level of parents, family pattern, delivery term, birth weight, and type of feeding. Further studies are needed to clarify the factors affecting BMD of children and earlier age, included infants and even prenatal life. If any association is revealed and persist until the attainment of peak bone mass, osteoporosis prevention programs are needed to be start very early in the life cycle.

• 대한치과교정학회지
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• 제26권3호
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• pp.247-254
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• 1996

골격성 III급 부정교합자의 설골 위치와 기도를 평가하고 이들 사이의 상관관계를 알아보기 위해 부산대학교병원 치과교정과에 내원한 16세 이상의 환자 47명과 치과대학에 재학중인 학생 44명을 대상으로 측모 두부방사선규격사진을 촬영하고 설골의 위치에 대한 전후방적, 수직적 거리 및 각도와 기도의 크기, 하악의 위치에 대해 통계적으로 분석하여 다음과 같은 결론을 얻었다. 1. S-APH, A-APH, N-APH, LAH-PBR, AA-PNS, PNS-ad는 I급 부정교합군과 III급 부정교합군 사이 에 유의한 차이를 보였다. 2. 설골은 III급 부정교합군에서 더 전방에 위치하였으며 경조직 기도 크기는 III급 부정교합군에서 I급 부정 교합군보다 더 작게 나타났다. 3. 다수의 계측치, 특히 설골의 수직적 및 각도 계측치와 기도 크기가 남성과 여성에서 유의한 차이를 보였다. 대개 남성에서 여성보다 수치가 크게 나타났다. 4. 설골의 위치와 기도 크기 사이에 유의한 상관관계는 없었으며 하악의 위치와 기도 크기 사이에도 유의한 상관관계는 없었다. 5. S-APH는 W its appraisal과 역상관관계를 보였으며 A-APH, N-APH는 Wits appraisal과 순상관관계를 보였다. 설골의 수직적 계측치는 하안모 고경과 순상관관계를 나타냈다.

• Imaging Science in Dentistry
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• 제32권2호
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• pp.61-66
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• 2002

Purpose: To compare the bone height of implant sites measured using panoramic radiography and spiral CT. Materials and Methods : The available bone height was determined for 263 maxillary and mandibular implant sites in 59 patients. Distortion was calculated using the metal bar for the panoramic radiographs. Results: Significant differences in mean bone height between the two imaging modalities were found in maxillary and mandibular anterior regions (p<0.05). The mean difference in bone height recorded by the two techniques was smallest in the maxillary and mandibular molar areas (0.8 mm), and greatest in the mandibular anterior region (1.3 mm). With the exception of the mandibular anterior region, ninety percent of all the sites showed measurement differences within 2 mm. Conclusion: A safety margin of 2 to 3 mm is called for when utilizing panoramic radiography, otherwise additional imaging modality such as computed tomography is necessary to obtain accurate measurements.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.527-528
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• 2006

In the proposed research plan, the effects of anisotropic and time-dependent mechanical properties on nanoindentation measurements of osteonic lamellae in a human cortical bone are investigated. The most popular method(Oliver-Pharr method) in nanoindentation data analysis is based on the assumption of elastic isotropy. Since cortical bone has exhibited anisotropy, it is necessary to consider the effects of anisotropy on nanoindentation measurement for cortical bone. By comparison with the contact area obtained from monitoring the contact profile in FEA simulations, the Oliver-Pharr method was found to underpredict or overpredict the contact area due to effects of anisotropy. The mount of error depended on the indentation orientation. The indentation modulus results and were also similar to moduli calculated from mathematical model. The Oliver-Pharr method has been shown to be useful for providing first order approximations in analysis of anisotropic mechanical properties of cortical bone, although the indentation modulus is influenced by anisotropy.