• Imaging Science in Dentistry
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• v.52 no.1
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• pp.83-91
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• 2022

Purpose: This study assessed the associations between chronological age, dental maturation (DM), cervical vertebrae maturation (CVM), and hand-wrist maturation (HWM) in individuals aged 9-19 years. In addition, this study aimed to derive practical methods to evaluate the skeletal age using DM, CVM, or HWM for orthodontic, medical, and forensic purposes and to compare which of these 3 developmental parameters is more accurate for estimating the age of individuals in a Turkish population. Materials and Methods: Panoramic, lateral cephalometric, and hand-wrist radiographs of 284 patients aged 9-19 years were used in this study. The DM, CVM, and HWM stages were determined. The Kolmogorov-Smirnov, kappa, Wilcoxon, Kruskal-Wallis, chi-square, and Spearman correlation tests and simple linear regression analysis were used for statistical analysis. The significance level was 0.05. Results: Statistically significant differences were found between chronological age and DM, chronological age and CVM, and chronological age and HWM in both sexes (P<0.05). DM did not show statistically significant differences according to sex (P>0.05), but CVM and HWM were statistically different between males and females (P<0.05). The DM-estimated age yielded more accurate values than the other methods. Conclusion: All correlations between skeletal and dental stages were statistically significant. Our results showed that there was no statistically significant difference between chronological age and DM-estimated age. Therefore, it can be concluded that DM stages have the potential to be used for legal purposes.

• Imaging Science in Dentistry
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• v.53 no.2
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• pp.91-99
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• 2023

Purpose: This systematic review aimed to investigate the correlation between chronological age and dental pulp volume in cone-beam computed tomography (CBCT). Materials and Methods: The literature was searched in 4 databases(PubMed, Scopus, Web of Science, and Google Scholar). Within each study, the outcome of interest was the correlation (r) between chronological age and pulp volume. A random-effect meta-analysis was conducted. Subgroup analysis was carried out according to sex and tooth type. Results: Of 5,693 identified studies, 27 fulfilled the inclusion criteria and were selected for meta-analysis. These articles focused on single-rooted teeth (n=21), multi-rooted teeth (n=6), maxillary teeth (n=14), mandibular teeth (n=6), and maxillary and mandibular teeth (n=12). The relationship between chronological age and dental pulp volume was examined in the entire population (r= -0.67), men (r= -0.75), and women (r= -0.77) in single- and multi-rooted teeth. The results of the total population analysis showed a relatively strong negative relationship between age and pulp volume. Conclusion: This study suggested that CBCT is a reliable and repeatable tool for dental age estimation. A strong inverse relationship was observed between pulp chamber volume and age. Further studies on the correlation between chronological age and pulp volume of multi-rooted teeth may be beneficial.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.305-330
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• 1992

This study intends to investigate the processing of the bibliographic relationships in the MARC formats based on the analysis to the related cataloging rules. In the traditional cataloging rules, many methods are used to process the bibliographic relationships(vertical, horizontal, and chronological), including analytics, references, notes, and independent entry. Linking entry fields in the MARC formats have been introduced mainly to process the chronological relationship in the serials, but later expanded, as a chronological in MARC format, to include other relationships applied to all other materials. Comparative analysis on the linking entry suggests that there are rare differences between UNIMARC and USMARC formats except the terminology and display constants, and that it is desirable in the KORMARC and JAPAN MARC to introduce the linking entry more comprehensively.

• Journal of Korean Dental Science
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• v.11 no.1
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• pp.1-4
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• 2018

Purpose: The aim of this study was to evaluate the ossification and maturation of the midpalatal suture in young Koreans using cone-beam computed tomography (CBCT). Materials and Methods: The study sample consisted of 40 patients with ages from 8.2 to 23.6 years who visited the Department of Orthodontics, Chung-Ang University Dental Hospital. CBCT images were taken for diagnosis. From the CBCT image, morphological stages and Hounsfield units (HU) of midpalatal suture were obtained to evaluate the midpalatal suture maturation. Spearman's correlation coefficients were calculated to analyze relationships between chronological age, morphological stage, and HU. Result: There was a wide variation in the morphology of the midpalatal suture in each age group. It showed a modest relationship between the chronological age and the degree of morphological stages. Also there was a modest relationship between the chronological age and HU. In contrast, there was a significant relationship between morphological stages and HU of midpalatal suture (P<0.01). Conclusion: CBCT images can be used for the evaluation of midpalatal suture maturation. For the estimation of the prognosis of rapid maxillary expansion, CBCT may be reliable for the assessment of the maturation of the midpalatal suture.

• The Journal of Pediatrics of Korean Medicine
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• v.28 no.1
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• pp.43-51
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• 2014

Objectives The purpose of this study is to find out the relationship between mid parental height (MPH), birth weight, current growth condition of children (height, weight, BMI, body fat percentage, bone age) and final height of the future. Methods The study was conducted with 237 children, who were 12 - 14 years old. They were analyzed to find out the relationship between MPH, birth weight, height, current weight, BMI, body fat percentage, bone age and predicted height. Results 1. As MPH was increased, height and predicted height were also increased. As MPHs in girls were increased, 'bone age - chronological age' were decreased. As MPHs in girls were increased, body fat percentages were decreased. 2. As birth weights were increased, height, weight, BMI and body fat percentages were also increased in boys. 3. As body fat percentage was increased, predicted height was decreased. As 'bone age - chronological age' was increased, predicted height was decreased. As BMI was increased, 'bone age - chronological age' was increased. As body fat percentages in boys were increased, heights were decreased. As body fat percentages in girls were increased, 'bone age - chronological age' were increased. Conclusions MPH, birth weight, current growth condition (height, weight, BMI, body fat percentage, bone age) and predicted height are correlated to each other. There are some differences between boys and girls in these relationships.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.2
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• pp.131-144
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• 2009

Objectives : The purpose of this study is to have better data and to make efficient clinical reviews on pre-school children's growth based on two measurements; Body composition for measuring body volume and bone age for potential growth. Methods : The study was conducted with 221 children(118 of boys and 103 of girls) from three kindergartens. Body compositions(soft lean mass, body fat mass, percent body fat) were measured by bioelectrical impedance analysis, bone age was measured by bone density through ultrasonic image of calcaneus. Results and Conclusions : 1. The higher level on weight or BMI, the more averages of soft lean mass, body fat mass, percent body fat. 2. The average bone ages and bone age-chronological age were lower in under 50 percentile's group, but it was higher in upper 50 percentile's group. Also, children with high BMI had older in bone ages and bone age-chronological age. 3. The higher in height percentile based on the bone age; there were more soft lean mass. 4. The averages of bone age and bone age-chronological age were significantly decreased, the more percentiles of height according to bone age were big, they were higher than total average in under 50 percentile's group of height, lower than total average in over 50 percentile's group of height in both boys and girls. 5. The average of MPH were significantly decreased in top percentiles of children's height distribution. Also, in the upper percentiles of height distribution based on bone age were big in only boys. 6. The body compositions(soft lean mass, body fat mass, percent body fat) were related to body volume growth, which can he measured by weight or BMI. The bone age, bone age-chronological age, and MPH were related in terms of hight. The body volume growth was a little hit related with potential growth.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.289-293
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• 2013

Purpose: This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Materials and Methods: Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. Results: The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ${\geq}15$ to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was $19.9{\pm}2.6$ years. That for the left side was $20.2{\pm}2.7$ years. The mean ages of the male subjects were $20.1{\pm}3.3$ years and $19.8{\pm}2.7$ years for the right and left sides, respectively. Conclusion: It might be possible to predict chronological age from the eruption height of the wisdom teeth.

• Journal of Gastric Cancer
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• v.1 no.3
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• pp.161-167
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• 2001

Purpose: Although gastric carcinomas occur throughout the world and the incidence is on the decrease, they remain the most common type of carcinoma in Korea. Significant advancements in the diagnostics and the surgical treatment of gastric carcinomas have been achieved during the last three decades. The present retrospective study was undertaken to investigate the chronological changes in the clinical features, including clinicopathological findings, operative treatment, and prognosis of gastric carcinomas. Materials and Methods: A total of 1973 patients with a primary gastric adenocarcinoma who had been treated surgically during the period from 1983 to 1998 at the Department of Surgery, Korea University College of Medicine, were divided into two groups to evaluate chronological changes: 1007 patients had been treated during the period from 1983 to 1992 (early period) and 966 patients during the period from 1993 to 1998 (late period). Chronological changes in age, sex, ratio of early gastric cancer (EGC), and resectability were analyzed in all 1973 cases. For the 1755 resected cases, we also studied the chronological changes in the clinicopathological and treatment factors between the early-period (n=894) and the late-period (n=867) groups. Results: There were significant differences between the two periods with regard to age and ratio of EGC: EGC was more frequent in the late period. Univariate analysis of resected cases showed that gross type, tumor size, depth of invasion, UICC stage, and histological type were statistically significant. The analysis of the treatment factors revealed that total gastrectomies and extended lymphadenectomies were more frequent during the late period. The number of lymph nodes dissected was $26.0\pm12.7$ in the early period and $33.4\pm14.1$ in the late period (p<0.01). The 5-year survival rate in all cases was $51.4\%$ in the early period and $55.9\%$ in the late period. The stage-related survival rates (UICC 4th Ed., 1987) in the early vs. the late periods were $92.9\%\;vs.\;95.5\%$ in stage IA, $82.1\%\;vs.\;91.1\%$ in stage IB, $76.5\%\;vs.\;73.1\%$ in stage II, $46.5\%\;vs.\;52.1\%$ in stage IIIA, $14.5\%\;vs.\;33.6\%$ in stage IIIB, and $2.8\%\;vs.\;8.8\%$ in stage IV. There was a statistically significant difference in survival between stage IIIB and IV. Conclusion: These results suggest that the differences in the clinicopathological findings are related primarily to the increased number of early gastric cancer cases in the late period and that the improved survival noted during the late period for in stage IIIB and IV cancers might be related to extended surgery.

• Journal of the Korean Geographical Society
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• v.44 no.1
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• pp.17-30
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• 2009

Paleostudies using lake sediment are essential to reconstruct environmental history of cental Mexico, where few documents on ancient civilizations and the colonial period exist. This study aims to reveal changes in the soil erosion rates through the calculation of sediment influx into the lake. The calculation is based on different kinds of chronologies and LOI. Sediment influx and dates for important events could be obtained in great detail through various chronological methods. Results show that corn agriculture was the most important reason to degrade the environmental status of the lake basin and European cattle raising was not much influential within the lake basin at least. It was possible to reveal a lot of recent environmental changes in detail, because the lake sediment used for this study has a very high sedimentation rate. Also, due to an accurate chronological framework, fundamental problems with the sediment were solved and reliable results could be produced.

• The Journal of Pediatrics of Korean Medicine
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• v.31 no.4
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• pp.31-38
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• 2017

Objectives The purpose of this study was to find out the clinically reliable relationships between the Risser sign and chronological age, bone age, menarche, and adult height prediction (AHP) and to evidence the reliability of the Risser sign. Methods This study had been carried out with 50 children who had their growth checked in an oriental medical hospital from January 2015 to February 2017. We investigated Risser sign in AP X-rays with iliac crest, bone age, AHP for all 50 children and the timing of menarche from the 22 girls in the study subjects. We also investigated a correlation between the Risser stage and the other indicators to analyze statistical data. Results The mean chronological ages of Risser 1, 2, 3 and 4 were 11.2, 12.6, 14.4, and 15.5 years respectively for the boys and 10.8, 12.2, 13.8 and 14.8 years respectively for the girls. The mean bone ages of Risser 1, 2, 3 and 4 were 12.3, 13.6, 15.7 and 16.5 years respectively for the boys and 11.7, 13.8, 14.3 and 14.9 years respectively for the girls. We analyzed 22 girls' Risser stages in accordance with the duration from menarche. The result showed that in the first six months after menarche, all girls were in Risser 1 and 2; in the next six months, the girls were in Risser 2 on average; in the next 12 months, all girls were in Risser 3 and 4; after more than two years from menarche, all girls were in Risser 4. The mean remaining growth height of Risser 1, 2, 3 and 4 were 27.8, 17.3, 4.4 and 1.0 cm respectively for the boys and 14.5, 5.1, 3.1 and 1.1 cm respectively for the girls. The Risser stage was correlated strongly with chronological age (Spearman's rho=0.707 (boy), 0.841 (girl)), bone age (Spearman's rho=0.869 (boy), 0.875 (girl)), duration from menarche (Spearman's rho=0.909) and remaining growth height (Spearman's rho=-0.784 (boy), -0.878 (girl)). Conclusions This study showed that the Risser sign can be useful in assessing skeletal maturity and predicting remaining growth height based on the Risser stage and the other growth indicators.