• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.532-542
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• 2007

The purpose of study was to review the transition of dentition according to the evolution of man to know the background of the dental problems like hypodontia and malocclusion. Man is Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Primates, Suborder Haplorrhini, Superfamily Hominoidea, Family Hominidae, Genus Homo, Species Sapiens by taxonomy. The first hominid was Australopithecus which appeared c. 4 millions of years ago and showed bipedalism and distinct dentition. Homos began with H. habilis who appeared c. 2.5 millions of years ago and made stone tools, and then H. erectus and H. neanderthalensis appeared and disappeared until H. sapiens came. The dental formula of primitive mammalians which was I3 C1 P4 M3 changed to I2 C1 P4 M3 of primitive primates, to I2 C1 P3 M3 of Haplorrhini, and to I2 C1 P2 M3 of hominoids. That of H. sapiens is changing to I2 C1 P2 M2.The box type dentition of hominoids changed to the omega type dentition of Australopithecus, and to the parabolic type of H. sapiens. The size of teeth decreased continually, especially the canine and sexual dimorphism. The dentition moved backward and downward to the cranial crown according to the increase of the brain and decrease of the jaws. It was suggested that the change of diet to the starchy foods, food processing, and the development of cooking reduced the necessity of mastication and caused the change of dentition. The future of H. sapiens who is quite a new species in the earth histroy and is now causing the mass extinction of other species is hard to see. It seems that hypodontia and malocclusion are related to the dentition change according to the evolution of man and is likely to increase.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.23-34
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• 2005

Collective changes caused by orthodontic tooth movement evaluated in a specific treatment modality could give suggestive information on the specific treatment strategy. The aim of this study was to investigate retrospectively the characteristics of the orthodontic tooth movement during surgical-orthodontic treatment in order to provide an effective presurgical orthodontic treatment planning for the maxillary premolar extraction modality In the skeletal Class III malocclusion patient. Pre- and post-treatment dental casts of skeletal Class III malocclusion patients with nonextraction (N=:24) and the maxillary premolar extraction (N=31) were collected. The angulation and inclination measuring gauge(Invisitech Co. Seoul, Korea) was used to evaluate the orthodontic tooth movement. The changes in the maxillary and mandibular dental arch widths were also measured from the canines to the second molars. As a result, more palatal inclination change in the maxillary dentition was found with the premolar extraction modality than with the nonextraction modality. Linear regression analysis showed that the inter-arch width coordination was mainly due to the inclination changes of maxillary posterior teeth We conclude that the indications and proper treatment planning for surgical-orthodontic treatment in skeletal Class III malocclusion with maxillary premolar extraction could depend partly on the magnitude of the transverse inter-arch coordination especially in the maxillary dentition.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.19-31
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• 2000

Developmental changes of dental arch width and length from 6.6 to 13.6 yews of age have been studied in twenty boys and thirteen girls in Korean school children. A series of 8 dental casts obtained from each child was measured in the intercanine width, intermolar width and arch length. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and corresponding graphs were drawn. The finding of this study can be summarized as follows : 1. Maxillary intercanine widths increased until age of 13.5 in males and age of 12.5 in females. On the other hand, mandibular intercanine widths increased until age of 11.5 in males and age of 9.6 in females and after there were no changes. 2. Maxillary intermolar widths increased until age of 13.5, but annual increments reduce from age of 12.5 in both sex. Mandibular intermolar widths increased until age of 13.5 in males and age of 12.5 in females. Annual increments of maxillary intermolar width greater than those of mandibular intercanine width in both sex. 3. Maxillary dental arch lengths increased until age of 10.6 in both sex, and after decreased until age of 13.6. Mandibular dental arch lengths increased until age of 10.5 in males and age of 9.6 in females, and after decreased until a9e of 13.6. 4. Developmental changes of dental arch width and length showed individual variation.

• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.43-49
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• 2002

When we deal with maxillary and mandibular anterior dental arches showing problems in occlusal relation and aesthetics caused by malformations of teeth and congenital missing, et al during the orthodontic treatment, we could not often decide the functional occlusion by only relying on the orthodontic treatment. If orthodontists can predict what kinds of treatments are needed for functional occlusion in maxillary and mandibular anterior dental arches, they can not only effectively treat patients but also facilitate the cooperation with other field during the treatment, Our previous research showed the correlation among intercanine width, segment depth and arch perimeter by using the Korean normal occlusion model. At this time, we produced the computer application program by taking advantage of this correlation. And then, we applied this program to setting up the treatment plans for 2 patients with the damaged maxillary and mandibular dentures. With the help of this program, we could not only easily acquire the information about the change of variables required by treatment plans but also intercanine width, segment depth and arch perimeter. Later, if we can the information about the relationship between the change of the angle of incisors depending on facial types and arch forms and, in addition, can acquire the appropriate intercanine width, we can have the ability to produce the 3 dimensional occlusogram for the anterior dental arch forms.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.17-27
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• 1998

Study on growth change of dental arch is considered to both an important data in orthodontic diagonsis and treatment planning as well as analysis of treatment results , also, arch form is important in anthropology and dentistry, even more so in prosthodontics and orthodontics. In the field of orthodontics, studies on the functional aspect of upper and lower teeth and maintenance of stability of dentition and occlusion were carried out from the early days. Some of the early studies include explanation of growth change in dental arch from measuring directly fom human stroll, and afterwards, cephalometrics x-rays were introduced; accordingly, studies using cephalometric measurement and linear measurements of study models were often performed. By this method, arch width, arch depth and perimeters were measured, and growth change or dental arch was studied. The subject ror this study were sn children(boys and girls or ages from 3 yens to 12 years from Kang-won district and Seoul, who has no history of orthodontic treatment and who show healthy status and normal growth and development. Cephalometric x-ray, panoramic x-ray, and study model were taken for each subject consecutively for 2 years, and the subjects are still followed up. 400 pairs of study models from the past two years were used in this study; mesio-distal diameater of each tooth, intercanine width, intermolar width, canine depth, molar depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and representation graph were drawn. The following conclusion were obtained. 1. Intercanine width showed gradual increase until the age of 10-years and after that, showed no increase. 2. Intermolar width in upper arch showed gradual increase : intermolar width in lower arch showed no significant chang, and after the age of 9-years, showed increase. 3. Cainine arch depth showed relatively rapid increase after the age of 6-years, and this pattern was more obvious in lower arch. 4. Molar arch depth increased gradually in both archs and it decrease after the age of 10-years : this phenomenon was more prominent in the lower arch. 5. Arch perimeter showed gradual inerease and convert to plateau at the age of 10-years, after that, it decreased. this pattern was more prominent in lower arch.

• Digital Contents
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• no.6 s.157
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• pp.96-97
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• 2006

상위20위권내 게임들의 순위 변화가 어느 때보다 치열했던 한달이었다. 특히, 톱10을 형성하고 있는 게임들의 경우, 순위변동이 거의 없었던 것을 감안했을 때 <스페셜포스>, <스타크래프트>, <워크래프트 3>를 제외한 나머지 게임들의 순위에 모두 변화가 일어난 5월 한달이었다. 지난달의 순위 경쟁이 어느 때 보다 치열했던 것을 알 수있다.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.283-298
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• 2008

Objective: The purpose of this study was to investigate changes in the mandibular dental arch from presurgical orthodontic treatment and orthognathic surgery, and to evaluate the relationships between the pretreatment records and changes of mandibular dental arch in skeletal Class III malocclusion individuals. Methods: Lateral cephalometric radiographs and mandibular study models of 31 adults with skeletal class III malocclusion were taken and measured. All measurements were evaluated statistically by ANOVA, Scheffe's Post Hoc, and paired t-test, and correlation coefficients were evaluated. Results: No significant difference in Mn-LMMC, Mn-LIE, Mn-MnOcc was detected between pretreatment and presurgical groups. Statistically significant but low correlations were demonstrated between the initial arch length discrepancy (ALD) and change in ICW, IPW1 (r = 0.492, 0.615) and change in arch length (r = 0.641). No association was seen between the initial depth of curve of Spee and change in mandibular incisor angle and arch width or arch length. Regression analysis showed that the amount of change for arch length and IPW1 could be explained by 64.0% and 75.8% of the pretreatment variables respectively. Conclusions: This study suggests that orthognathic surgery results can be predictable by measuring the pretreatment records.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.197-202
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• 2013

The purpose of this study was to examine the relationship between the physique of 147 dental hygiene students and the size of their dental arch. A survey was conducted, and impression taking was carried out at the same time to measure the arch length and width of the students. The findings of the study were as follows: 1. 74.8 percent of the students got a dental checkup over the past year. 86.4 percent breathed through the nose. 18.4 percent had ever received orthodontic treatment, and 49.7 percent had ever had their tooth extracted. 94.6 percent were fond of refined food, and 52.4 percent had a liking for hard food. 2. There were no statistically significant differences in arch length and width according to all the variables that related the size of dental arch. 3. Out of the physique variables, weight was identified as a variable to make a statistically significant difference to arch length and width. A heavier weight led to larger mandibular inter-canine width and larger maxillary inter-molar width. 4, A heavier weight had a weaker positive correlation to inter-canine width and inter-molar width. Arch length and width were most closely linked to maxillary inter-molar width and mandibular inter-molar width. The above-mentioned findings show that weight exerted an influence on the form of dental arch among the physique variables. In the future, sustained research efforts should be made to keep track of the relationship between the change of physique and the change of dental arch to improve the stability of occlusion and promote oral health.

• 해운
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• no.10 s.21
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• pp.25-28
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• 2005

최근 전 세계 해운업계에 두가지 변화의 바람이 거세지고 있다. 하나는 해운업체간 M&A이며, 또 다른 하나는, 전략적 제휴(ALLIANCE)의 강화 움직임이다. 이같은 흐름은 세계 해운기업의 생존과 밀접한 관련이 있으며, 국내 해운업계에도 커다란 영향을 미칠 것으로 보인다. 향후 세계 정기선시장은 거대 얼라이언스와 중대형선사들간의 합종연횡으로 경쟁이 더욱 치열해 질 것으로 전망되고 있다.(편집자 주)

• 대한치과교정학회:학술대회논문집
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• 1997.11a
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• pp.22-25
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• 1997