• 대한치과교정학회지
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• 제46권5호
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• pp.323-330
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• 2016

Objective: The purpose of this study was to determine whether the results of fractal analysis can be used as criteria for midpalatal suture maturation evaluation. Methods: The study included 131 subjects aged over 18 years of age (range 18.1-53.4 years) who underwent cone-beam computed tomography. Skeletonized images of the midpalatal suture were obtained via image processing software and used to calculate fractal dimensions. Correlations between maturation stage and fractal dimensions were calculated using Spearman's correlation coefficient. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. Results: The distribution of maturation stages of the midpalatal suture according to the cervical vertebrae maturation index was highly variable, and there was a strong negative correlation between maturation stage and fractal dimension (-0.623, p < 0.001). Fractal dimension was a statistically significant indicator of dichotomous results with regard to maturation stage (area under curve = 0.794, p < 0.001). A test in which fractal dimension was used to predict the resulting variable that splits maturation stages into ABC and D or E yielded an optimal fractal dimension cut-off value of 1.0235. Conclusions: There was a strong negative correlation between fractal dimension and midpalatal suture maturation. Fractal analysis is an objective quantitative method, and therefore we suggest that it may be useful for the evaluation of midpalatal suture maturation.

• 치위생과학회지
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• 제21권4호
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• pp.219-226
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• 2021

Background: Proper detection and management of dental plaque are essential for individual oral health. We aimed to evaluate the maturation level of dental plaque using a two-tone disclosing agent and to compare it with the fluorescence of dental plaque on the quantitative light-induced fluorescence (QLF) image to obtain primary data for the development of a new dental plaque scoring system. Methods: Twenty-eight subjects who consented to participate after understanding the purpose of the study were screened. The images of the anterior teeth were obtained using the QLF device. Subsequently, dental plaque was stained with a two-tone disclosing solution and a photograph was obtained with a digital single-lens reflex (DSLR) camera. The staining scores were assigned as follows: 0 for no staining, 1 for pink staining, and 2 for blue staining. The marked points on the DSLR images were selected for RGB color analysis. The relationship between dental plaque maturation and the red/green (R/G) ratio was evaluated using Spearman's rank correlation. Additionally, different red fluorescence values according to dental plaque accumulation were assessed using one-way analysis of variance followed by Scheffe's post-hoc test to identify statistically significant differences between the groups. Results: A comparison of the intensity of red fluorescence according to the maturation of the two-tone stained dental plaque confirmed that R/G ratio was higher in the QLF images with dental plaque maturation (p<0.001). Correlation analysis between the stained dental plaque and the red fluorescence intensity in the QLF image confirmed an excellent positive correlation (p<0.001). Conclusion: A new plaque scoring system can be developed based on the results of the present study. In addition, these study results may also help in dental plaque management in the clinical setting.

• 대한소아치과학회지
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• 제34권4호
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• pp.551-559
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• 2007

하악골 성장을 평가하는 데 경추골 성숙도가 수완부골 성숙도만큼 유용한가 규명하고자 본 연구를 시행하였다. 정상교합을 가진 만 8세$\sim$만 16세 여성 292명을 연구대상으로 하여 진단석고모형, 측모두부규격방사선사진, 그리고 수완부방사선사진을 이용하여 경추 및 수완부의 골성숙도를 비교하여 다음과 같은 결과를 얻었다. 1. 연령 증가에 따라 경추 및 수완부의 골성숙도가 일정하게 증가하였다. 2. 경추골 성숙도가 증가할수록 Ar-Go, Go-Me, N-Go, S-Gn, N-Me이 일정하게 증가하였다. 3. 수완부골 성숙도가 증가할수록 Ar-Go, Go-Me, N-Go, S-Gn이 일정하게 증가하였다. 4. 경추골 성숙도 3단계와 4단계 사이에서 Ar-Go, Go-Me, N-Go, S-Gn이 크게 증가하였고, 수완부골 성숙도 6단계와 7단계 사이에서 Go-Me, S-Gn이 크게 증가하였다. 5. Ar-Go, Go-Me, N-Go, S-Gn, N-Me은 경추 및 수완부 골성숙도와 각각 유의 한 상관성을 보였다. 이상의 결과는 하악골 성장을 평가하는 데에 경추골 성숙도가 수완부골 성숙도처럼 유용하게 사용될 수 있음을 시사한다.

• International Journal of Oral Biology
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• 제30권4호
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• pp.131-134
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• 2005

In the present study, performances of several in vitro maturation (IVM) systems for porcine follicular oocytes were evaluated, and an efficient chemically defined IVM system for porcine oocytes was proposed. The proposed one-step culture system supplemented with polyvinylalcohol (PVA) gave competitive efficiencies in terms of oocyte maturation and blastocyst development after parthenogenetic activation and in vitro culture, compared with the conventional two-step culture system by a supplementation of porcine follicular fluid (pFF). Additionally, it is identified that the proposed chemically defined one-step culture system yielded the comparable level of blastocyst production to the conventional maturation system in porcine somatic cell nuclear transfer (SCNT). Therefore, one can eliminate un-expected effects accompanied by supplementation of pFF. No medium replacement during whole maturation period is an additional benefit by applying this new system. Thus, these data support that the developed PVA supplemented chemically defined one-step IVM system for porcine follicular oocyte might be used in porcine SCNT program.

• 대한소아치과학회지
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• 제37권1호
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• pp.57-64
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• 2010

본 연구는 수직적 안모형태와 치아성숙도의 관계를 평가하고 이러한 연관성에 대한 사춘기 성장의 영향을 평가하기 위한 것이다. 이번 연구를 위해 7세에서 9세, 13세에서 15세 환자 1306명을 Ricketts의 VERT index를 이용하여 수직적 안모 형태를 분류하였고 환자들의 치령을 Demirjian법으로 평가하여 다음과 같은 결과를 얻었다. 1. 모든 군에서 치령이 역령과 비교 시 통계적으로 유의한 수준에서 크게 측정되었다. 2. 사춘기 연령군에서 brachyfacial type의 경우가 dolichofacial type 보다 치아성숙도가 크게 나타나는 경향을 보였다. 여성의 경우는 통계적으로 유의성있게 차이가 나타났으며, 남성의 경우는 통계적 유의성은 보이지 않았다. 3. Brachyfacial type의 경우 사춘기전 군들과 비교 시 사춘기 군들에서 치아성숙도가 유의성있게 높게 나타났으며, dolichofacial type의 경우는 연령층간 치아성숙도의 차이를 보이지 않았다.

• Journal of Korean Dental Science
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• 제11권1호
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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.

• 대한치과교정학회지
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• 제48권1호
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• pp.39-47
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• 2018

Objective: The aim of this study was to establish the normative data of dentofacial transverse dimensions according to the skeletal maturation stage in Korean adolescents with good occlusion, assess gender differences and determine correlations between transverse variables. Methods: A total of 577 Korean subjects between ages 7 to 19 years and exhibiting skeletal Class I occlusion were categorized by skeletal maturation index (SMI) of Fishman using hand-wrist radiographs. Dentofacial transverse dimensions were assessed using posteroanterior cephalograms. Independent two-sample t-tests were used to analyze differences between genders. Pearson correlation coefficient was used to determine the correlation between transverse measurements. Results: Dentofacial transverse norms relevant to skeletal maturation stages were established. The average maxillomandibular width difference and ratio at growth completion was 22.16 mm and 77.01% for males; 23.70 mm and 74.06% for females, respectively. Males had greater facial, maxillary and mandibular widths compared to females at every SMI stage. The maxillary and mandibular intermolar widths showed the strongest correlation for both sexes (r = 0.826 for males, r = 0.725 for females). Conclusions: Dentofacial transverse norms of Korean adolescents were established according to developmental stage. All dentofacial widths were greater in males at growth completion. Maxillary and mandibular intermolar widths were strongly correlated. This study may serve as a guideline for the assessment of dentofacial transverse growth according to skeletal maturation stage in Korean adolescents with good occlusion.

• 대한소아치과학회지
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• 제42권2호
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• pp.144-150
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• 2015

유치열기의 3급 부정교합은 조기 치료가 추천되지만 정확한 진단이 쉽지 않다. 3급 부정교합의 골격성 특성과 치아 발육상태 사이에 연관성이 있다면 골격성 3급 부정교합의 감별 진단을 위한 평가 항목으로 치아성숙도가 활용될 수 있을 것이다. 본 연구는 유치열기의 골격성 혹은 비골격성 3급 부정교합으로 진단받은 환아를 대상으로 치아 석회화도 및 제 1대구치의 맹출률을 비교, 분석하여 상하악의 치아성숙도 차이가 유치열기 3급 부정교합의 감별 진단시 평가 항목으로 사용될 수 있는지 알아보기 위한 목적으로 시행되었다. 전치부 반대교합을 주소로 부산대학교 치과병원 소아치과에 내원한 유치열기 아동 중 비골격성 3급 부정교합군 18명과 골격성 3급 부정교합군 34명을 연구대상으로 선정하였다. 파노라마 방사선사진상에서 치령 및 제1대구치 맹출률을 비교, 분석하여 다음과 같은 결과를 얻었다. 골격 및 성별에 따른 역령과 치령의 차이는 존재하지 않았으며, 두 군 모두 역령에 비해 치령이 높게 나타났다(p < 0.05). 비골격성군과 골격성군의 상하악 맹출률의 차이는 각각 16.53%, 18.91%로 통계학적으로 유의한 차이를 보여(p < 0.05), 3급 부정교합의 감별 진단을 위한 평가 항목으로서 제1대구치 치아성숙도의 활용 가능성을 시사한다.

• 대한소아치과학회지
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• 제46권3호
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• pp.247-254
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• 2019

이 연구는 성장기 아동의 방사선 사진을 이용하여 상악 견치의 치아 성숙도와 골격적 성숙도를 평가하고, 상악 견치의 치아 성숙도와 골격적 성숙도 사이의 연관성을 알아보고자 하였다. 치아 성숙도는 Demirjian index (DI)를 이용하였고, 골격적 성숙도는 cervical vertebral maturation stages (CVMS)와 skeletal maturity indicators (SMI)를 이용하여 각각 경추골 성숙도와 수완부골 성숙도를 평가하였다. 그 결과, 남녀 모두 상악 견치의 DI와 CVMS 및 SMI 사이에서 유의하게 높은 상관관계를 나타냈다(p = 0.000). 이 연구를 통하여 상악 견치를 이용한 치아 성숙도 평가는 성장기 아동의 골격적 성숙도를 평가하는 보조적 수단으로 사용될 수 있음을 확인하였다.

• 대한치과교정학회지
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• 제42권1호
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• pp.11-16
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• 2012

Objective: This study aimed to evaluate the mean age of menarche, its secular trend in Korean women, and the relationship between malocclusion and the rate of skeletal maturation, as defined by menarcheal age. Methods: We retrospectively collected data on menarcheal age from 931 Korean women born during 1961 - 1997. Subjects were divided by the malocclusion type and birth-year decade into 3 and 4 groups, respectively. The mean menarcheal age for each group was determined, and one-way ANOVA was performed for intergroup comparison (p = 0.05). Two-way ANOVA was also performed to compare all the 12 subgroups (p = 0.05). Results: The mean age of menarche was 12.82 years for Korean women born during 1961 - 1997. A distinct downward secular trend of menarcheal age was noticed (p < 0.05). For the birth-year decade 1961 - 1970, the Class III malocclusion group showed earlier onset of menarche than the other malocclusion groups (p < 0.05), but the other birth-year groups did not show any significant difference in the type of malocclusion (p > 0.05). Conclusions: A positive secular trend towards earlier menarche exists among Korean women. Malocclusion does not show any significant relationship with the rate of skeletal maturation, as defined by menarcheal age.