• 대한치과교정학회지
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• 제18권1호
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• pp.217-225
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• 1988

This study was undertaken to examine relationship between tooth size and arch dimension in dental crowding. Two groups of dental casts were selected on the basis of dental crowding. One group, consisting of 51 pairs of dental casts (24 male and 27 female), exhibited remarkable dental crowding. A second group, consisting of 60 pairs of dental casts (30 male and 30 female), exhibited little or no crowding. Mean and standard deviation of the following parameters were used to compare two groups. individual and collective mesiodistal tooth diameters, buccal and lingual arch widths and arch area. The following results were obtained. 1. The crowed group revealed larger tooth size than noncrowded group. (p < 0.01) 2. The crowded group smaller maxillary dental arch dimension than noncrowded group except lingual arch width at canine region. (p < 0.01) 3. The corwded group revealed smaller mandibular dental arch dimension than noncrowded group except lingal arch width at second premalar region in the male and buccal arch width at canine, premolar region in the female. (p < 0.01) 4. The crowded group revealed smaller arch area than noncrowded group in the female (p < 0.01), but there was no significance in the male.

• 대한치과교정학회지
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• 제47권3호
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• pp.176-185
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• 2017

Objective: To evaluate the relationship of gingival thickness (GT) and the width of keratinized gingiva (WKG) with different malocclusion groups and the level of crowding. Methods: A total of 187 periodontally healthy subjects (121 females and 66 males) who presented at the Faculty of Dentistry in $Y{\ddot{u}}z{\ddot{u}}nc{\ddot{u}}$ Yil University for orthodontic treatment were enrolled in the study. The individuals involved in the study were divided into three groups; Angle Class I malocclusion, Angle Class II malocclusion, and Angle Class III malocclusion. Each group was classified as mild, moderate, or severe according to the level of crowding. WKG was determined as the distance between the mucogingival junction and the free gingival margin. GT was determined by the transgingival probing technique. Factorial variance analysis and the Duncan multiple comparison test were employed to identify the extent to which a difference was apparent between the groups according to these parameters. Results: It was determined that teeth in the mandibular anterior region display the thin gingival biotype. WKG and GT were observed as being higher at the mandibular incisor teeth in the severe crowding group and at the mandibular canine teeth in the mild crowding group. The GT of the mandibular right central and lateral incisors was found to be thinner in the Angle Class III group. Conclusions: Within the limits of this study, the results demonstrate that, there is no significant relationship of WKG and the mean GT in the mandibular anterior region according to the Angle classification.

• 대한치과교정학회지
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• 제51권2호
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• pp.86-94
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• 2021

Objective: This study aimed to investigate the effect of micro-osteoperforations (MOPs) on external apical root resorption (EARR) during the initial orthodontic alignment phase of maxillary anterior crowding. Methods: Thirty patients (25 females, 5 males; mean age, 22.66 ± 3.27 years) who presented with moderate crowding of the upper labial segment and underwent extraction-based fixed appliance treatment were recruited. They were randomly allocated to receive adjunctive therapy with MOPs (n = 15) or treatment with fixed appliances only (control group; n = 15). EARR was measured from long-cone periapical radiographs taken at the start and the sixth month of treatment. A correction factor for the enlargement difference was used to calculate EARR. Data were analyzed with descriptive statistics and repeated-measures analysis of variance. Results: The mean root lengths of 168 teeth were measured and showed no statistically significant difference (p > 0.05) after six months of fixed appliance treatment in the MOP (mean difference [MD] = 0.13 mm; 95% confidence interval [CI] = -0.10-0.35) and control group (MD = 0.14 mm; 95% CI = -0.10-0.37). Most of the roots in the MOP and control groups (42.86% and 52.38%, respectively) showed only mild resorption. Less than 8% of the roots in both groups (7.14% in the MOP group and 4.76% in the control group) showed moderate resorption. Conclusions: Acceleration of orthodontic tooth movement with adjunctive MOPs therapy during the alignment phase does not exacerbate EARR in patients with moderate crowding of the upper labial segment in comparison with controls.

• 한국조경학회지
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• 제30권6호
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• pp.79-97
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• 2003

The purpose of this paper is to analyze a causal model determining social carrying capacity(SCC) in natural parks, to answer the research question: What is the mechanism for determining SCC in natural parks (NP)\ulcorner After reviewing the literature on SCC and recreation activities in Korean natural parks, we constructed a conceptual framework and formulated the hypothesis of this research. We obtained data through a questionnaire which surveyed 487 visitors at 6 of the 73 NP in Korea during 2001, based on a stratified sampling method. We analyzed the data using descriptive statistical methods, the mean difference test, Pearson's correlation analysis, and path analysis method. We found that 1) The direct effect of resources, activity space(AS), visitor's expectation(VE), encounter, crowding, damage of resources(DR), maintenance condition of resources and facility(MCRF) to SCC are 3.45, 3.62, 2.75, 2.72, 1.32, and 4.77 times more important than that of crowding, respectively, while the indirect effect of resources, AS, VE, encounter, and DR to SCC is 13.03, 11.19, 3.34, 1.3, 2.05, 1.10, 0.05 and 2.30 times more important then that of crowding, respectively, 2) Causal effects of resources, facility, AS, VE, number of visitors(NV), encounter, crowding, VM, DR, and MCRF to SCC turned out to have 0.3523, 0.3321, 0.1751, 0.1465, 0.0307, 0.0762, 0.0604, -0.0510, -0.1177 and 0.2165, respectively, and 3) The causal effect of activity base(AB) and activity atmosphere(AA) to SCC turned out to have 2.57 and 1.1 times higher than that of MCRF, respectively. The research results suggest that 1) this conceptual framework is highly useful for the development of substantive theory and methodology; 2) management issues of AA and MCRF turned out to have 0.81 times in SCC that of AB, i.e, SCC can be significantly improved from control of AA and MCRF; and 3) supply of excellent resources and convenient facilities is needed to increase social carrying capacity. It is recommended that more empirical studies be performed in the future according to the season, visitor characteristics, and AS by NP.

• 대한치과교정학회지
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• 제25권5호
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• pp.593-604
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• 1995

하악 전치의 밀집은 가장 흔히 볼 수 있는 부정교합의 특징중의 하나이며 교정치료후의 안정성과 재발 측면에서도 중요 관심의 대상이다. 이를 유발시킬 수 있는 원인으로 그동안 많은 요소가 연구되어 왔으며 치아의 크기도 그 중의 하나이다. 현재 교정치료의 진단과 치료에 사용되고 있는 치아 크기 측정에서는 순설측 폭경의 의미가 간과되어 왔는데 Peck과 Peck이 이상적인 하악 전치부 배열을 가진 경우 절치의 근원심 폭경은 평균보다 작고 순설측 폭경은 평균보다 크다는 통계학적 수치를 발표하고 MD/FL index가 하악 전치부 밀집과 높은 상관관계를 가진다고 주장하였다. 본 연구는 한국인에 있어서 하악 절치의 형태 및 크기와 하악 전치부 밀집간의 상관관계, 그들과 전악궁의 치아 밀집간의 연관성을 알아보기 위해 시행되었다. 11세에서 17세에 이르는 154명의 석고 모형을 채득하여 Irregularity index 1 미만인 35명의 정상군과 Irregularity index 1 이상인 119명의 밀집군으로 분류하고 석고모형상에서 연관성 있다고 추정되는 계측항목을 측정한 후 통계처리하여 다음과 같은 결론을 얻었다. 1. 하악 절치의 근원심 폭경은 밀집군에서 큰 값을 보였으나 중절치에서만 유의성을 보였고, 순설측 폭경과 MD/FL index는 유의차가 없게 나타났다. 2. Irregularity index는 밀집군의 하악 절치의 근원심 폭경, MD/FL index와 유의성있는 상관관계를 나타냈으나 순설측 폭경과는 상관관계를 보이지 않았다. 또한 상하악의 Arch length discrepancy, 치관 근원심 폭경 총화와는 순상관 관계를, 하악 견치간 폭경과 제 1 소구치간 폭경과는 역상관관계를 나타내었다. 3. 상하악의 arch length discrepancy는 하악 절치의 근원심 폭경, overbite과 유의성 있는 상관관계를 나타내었고 순설측 폭경과는 상관관계가 나타나지 않았다. 하악의 arch length discrepancy는 하악 절치의 MD/FL index와, 상악의 arch length discrepancy는 측절치의 MD/FL index에서 상관관계를 나타내었다. 4. 정상군과 밀집군의 각 계측항목의 t-검정 결과 하악의 arch length discrepancy, overbite에서만 유의차를 나타내었다.

• 생명과학회지
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• 제29권7호
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• pp.762-768
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• 2019

참취, Doellingeria scabra Thunb. (이전의 학명: Aster scaber Thunb.)는 국화과의 다년생 초본으로 한국의 야생산지에서 흔히 찾을 수 있다. 본 연구는 강원도 태백시 매봉산에 분포하는 참취의 국지적 집단에 대해 패치 특성을 측정하고자 하였다. 이 종의 공간적 분포를 평가하기 위해 분산의 지수, Lloyd 평균 군집도, Morisita 지수 등을 통해 자료를 분석했다. 참취 집단의 평균 밀도는 2.94이었다. 참취는 작은 규모의 플롯에서는 일정한 분포 또는 임의 분포를 하였고, 두 개의 큰 규모 플롯($16{\times}32m^2$와 $32{\times}32m^2$)에서는 응집 형태로 분포했다. 평균 밀집도($M^*$)는 0.916이었다. 평균 patchiness index (PAI)는 0.796이었다. Morisita의 계수는 플롯 크기가 커짐에 따라 감소하는 경향을 보였다. 이 집단에서 Eberhardt 지수(IE)의 예상 값은 2.623이었다. 참취의 Moran's I 값에서 처음 5개 구간은 양의 값이었다. 그 중 4개는 유의성을 나타내어 개체간 유사성은 8 m 이내에서 발생한다고 볼 수 있다. 본 연구는 매봉의 참취군락뿐만 아니라 다른 산의 산림 생태계 내 참취 군락의 지속 가능한 유지 및 복원에 대한 이론적 근거를 제공할 수 있다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권6호
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• pp.516-525
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• 2004

Mandibular symphyseal distraction osteogenesis is an alternative approach for correcting mandibular transverse deficiencies and dental crowding. The traditional approaches for these are extraction of teeth and arch expansion with traditional orthodontic treatment. Also extractions are usually unavoidable in patients with severe crowding. The purpose of this study is to evaluate the effect of mandibular symphyseal distraction osteogenesis by use of tooth-borne expansion appliance. All of 12 patients had been performed distraction osteogenesis. The surgical procedures were accomplished under local anesthesia and intravenous sedation in an ambulatory surgical setting using a routine distraction protocol. The latency period was 5 days or 7 days after symphyseal osteotomies. The rate & rhyth is a intermittent, 0.75mm or 1.0 mm per day and stabilized for 6, 8 weeks after distraction. The time of orthodontic tooth movement after distraction was variable from 2 weeks to 8 weeks (mean 3 weeks). All patients had been evaluated with study casts, plain periapical films, panorama radiograms before & after surgery. Mandibular symphyseal distraction osteogenesis increased mandibular arch width and corrected dental crowding, with paralleling tooth-borne movement, without proclination of the mandibular incisors.

• 대한치과교정학회지
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• 제17권2호
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• pp.289-297
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• 1987

For the comparisons of dental archs and crowdings between musical wind instrument players groups and non-wind instrument players groups, 64 male wind instrument players and 31 non-wind instrument players group were selected. The results of the measurements were as follow. 1 Upper intercanine widths, upper basal arch widths, lower basal arch widths were statistically significant between musical wind instrument players groups (Class A, Class B) and non-wind musical instrument players group. 2 The mean value of upper intercanine width m Class A ($373{\pm}2.3mm$) was greater than than in Class B ($362{\pm}17mm$) and non-wind musical instrument players group($360{\pm}16mm$) 3 The mean value of lower basal arch width m Class B ($422{\pm}25mm$) was greater than that in non wind instrument players group ($395{\pm}28mm$). 4 The differences in the mean values of crowdings between Class A and Class Band non-wind instrument players group were not statistically significant.

• 한국조경학회지
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• 제30권1호
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• pp.29-43
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• 2002

The purpose of this paper is to examine atmospherical factors affecting user's satisfaction in natural park to answer the research question: what are the effects of atmosphere on user's satisfaction in natural parks(NP). After reviewing the literature, mechanism of NP, and use elements in NP, We constructed the conceptual framework and have formulated the hypothesis of this research. We had obtained data through a questionnaire, which surveyed 508 visitors at 6 of the 73 NP in Korea in 2001, based on stratified sampling method. We have analyzed the data using descriptive statistical methods, the mean difference test, Pearson's correlation analysis, and the multiple linear regression method. We found that 1) the five atmospheric variables, j.e., number of users(NOU), crowding, damage to park resources(DPR), and maintenance of park resources and facilities(MPRF), encounter level(EL) affecting user's satisfaction, have tuned out to be statistically significant at a five percent level. The direction of the relationship between user's satisfaction and MPRF, NOU, EL is the same as that of the dependent variable and the opposite of crowding, and BPR, 2) in bivariate analysis, the positive relationships between user's satisfaction and park resources, MPRF are fairly high and statistically significant. The higher the value of DPR, and crowing, the lower the degree of user's satisfaction, 3) in multivariate analysis, such variables as NOU, crowding, DPR, EL, and MPRF affecting user's satisfaction have been statistically significant at five percent level, and 4) the relative contribution of MPRF, park resources, park facilities, NOU, crowding, DPR, and size of activity space on user's satisfaction have been determined to have respectively 6.00, 4.78, 2.53, 1.83, 1.64, 1.59 and 2.03 times more important than that of EL. Among the atmospheric variables, MPRF is the most important at 1.26 times higher than that of park resources. The research results suggest that the development of devices for the increase in user's satisfaction and user management program based on the knowledge we have found, be recommended in the planning and development process of natural park. The approach adopted by this research is valid and useful for evaluation criteria of NP. It is recommended that more empirical studies by activity types, activity spaces, and seasons on atmospheric elements affecting user's satisfaction be performed in the future.

• 대한치과교정학회지
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• 제52권1호
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• pp.66-74
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• 2022

Objective: To investigate demographic and skeletodental characteristics of one-jaw (1J-OGS) and two-jaw orthognathic surgery (2J-OGS) in patients with skeletal Class III malocclusion. Methods: 750 skeletal Class III patients who underwent OGS at 10 university hospitals in Korea between 2015 and 2019 were investigated; after dividing them into the 1J-OGS (n = 186) and 2J-OGS groups (n = 564), demographic and skeletodental characteristics were statistically analyzed. Results: 2J-OGS was more frequently performed than 1J-OGS (75.2 vs. 24.8%), despite regional differences (capital area vs. provinces, 86.6 vs. 30.7%, p < 0.001). Males outnumbered females, and their mean operation age was older in both groups. Regarding dental patterns, the most frequent maxillary arch length discrepancy (ALD) was crowding in the 1J-OGS group (52.7%, p < 0.001) and spacing in the 2J-OGS group (40.4%, p < 0.001). However, the distribution of skeletal pattern was not significantly different between the two groups (all p > 0.05). The most prevalent skeletal patterns in both groups were hyper-divergent pattern (50.0 and 54.4%, respectively) and left-side chin point deviation (both 49.5%). Maxillary spacing (odds ratio [OR], 3.645; p < 0.001) increased the probability of 2J-OGS, while maxillary crowding (OR, 0.672; p < 0.05) and normo-divergent pattern (OR, 0.615; p < 0.05) decreased the probability of 2J-OGS. Conclusions: In both groups, males outnumbered females, and their mean operation age was older. The most frequent ALD was crowding in the 1J-OGS group, and spacing in the 2J-OGS group, while skeletal characteristics were not significantly different between the two groups.