• The Journal of the Korean dental association
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• v.51 no.6
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• pp.330-336
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• 2013

Considering the high prevalence, transverse control in adult patients presenting relatively narrow maxillary width is a challenging issue. This study compared the pattern of arch expansion induced by either miniscrew-assisted rapid palatal expander (MARPE) or continuous archwire engaged on self-ligating brackets. Age-matched adults groups(N=15 each) were treated with respective appliance. In both groups, all intercanine, interpremolar, and intermolar widths increased, and significantly greater change was noted in the intermolar region. Buccal tipping was minimal in both groups. Subsequent arch length increase, lingual tipping of incisors and distal tipping of molars were also found in both groups. According to the results, it can be concluded that the MARPE induced generally more arch expansion, particularly in the intermolar width, indicating that the adults showing buccal crossbite of the molars may have to undergo expansion via MARPE prior to arch alignment using continuous archwire.

• The korean journal of orthodontics
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• v.14 no.1
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• pp.115-125
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• 1984

A comparative study was undertaken to investigate the collapse of maxillary dental arch and palate in unilateral cleft lip and palate individuals. The material for this study consisted of 39 subjects with repaired unilateral cleft lip and palate (30 males, 9 females). The measurements of unilateral cleft lip and palate individuals were compared with the measurements of normal individuals (30 males, 30 females). All the subjects were in the mixed dentition stage and the mean age was almost the same. The following conclusions were obtained. 1. A large number of the maxillary dental arch of the unilateral cleft lip and palate individuals showed ${\Omega}$-shape, and the arch length was shorter than that of normal individuals. The intermolar width did not show significant difference between cleft group and group, but the intercanine width was mcuh smaller than that of normal individuals. 2. The palate of the unilateral cleft lip and palate subjects showed shorter and shallower form than that of normal subjects. 3. The palatal area of the unilateral cleft lip and palate subjects was smaller than that of normal subjects, and the cleft side area was much smaller than the opposing side area. 4. There was no significant sexual difference in measurements of maxillary dental arch and palate of the unilateral cleft lip and palate subjects.

• 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.18 no.1 s.25
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• pp.165-173
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• 1988

The purpose of this study was to investigate and evaluate what proportion is the characteristics in Korean dental arches with normal occlusion. Many others have already indicated Golden proportion in normal dental arches, but have not considered any racial and sociocultural differences. So the author postulated $(\sqrt{2})^n$ relations in Koreans. The materials were consisted of 134 dental casts with normal occlusion, which have never undergone orthodontic and prosthodontic procedures. Measurements were made on the arch dimensions using sliding caliper and data were computerized. The findings were as follows: 1. The width between the distal surfaces of the upper centrals, had $(\sqrt{2})^3$ relation with the width between the buccal surfaces of the upper 1 st premolars in Koreans. 2. The width between the distal surfaces of the lower laterals had $(\sqrt{2})$ relation with the width between the distal surfaces of the lower canines, and had $(\sqrt{2})^2$ relation with the distal surfaces of the upper centrals. 3. The width between the distal surfaces of the lower centrals had $(\sqrt{2})^2$ relation with the width between the distal surfaces of the lower laterals, and had $(\sqrt{2})^3$ relation with the width between the distal surfaces of the upper centrals.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.390-396
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• 2014

The purpose of this study was to examine the size, form of dental arch and occlusion type in college students in our country and the relationship of the factors. The subjects in this study were 210 selected dental hygiene students. The collected data were analyzed by a statistical package PASW 18.0. When their size, form and occlusion of dental arch were analyzed, the inter-canine width of the maxillary was 34.38 mm, and the inter-first molar width was 52.05 mm. The canine depth was 8.60 mm, and the first molar depth was 28.69 mm. As for the mandibular, the inter-canine width was 26.42 mm, and the inter-first molar width was 44.83 mm. The canine depth was 5.54 mm, and the first molar depth was 24.38 mm. Concerning the form of dental arch, the percentage of normal dental arch in the maxillary stood at 29.0, and that of crowding stood at 60.5. The percentage of spacing stood at 10.5. In the case of the mandibular, the percentage of normal dental arch stood at 29.0; crowding, 55.7; and spacing, 15.2. In relation to occlusion, the percentage of normal occlusion stood at 16.7. As to malocclusion, class I that accounted for 55.7 was most common, and class II and class III respectively accounted for 20.5 and 7.1. When the size of dental arch was compared according to the form and occlusion of it, dental arch was largest (45.95 mm) in size when the form of dental arch in the inter-first molar width of the mandibular was spacing. The size of dental arch was 44.73 mm when its form in the same region was normal, and that was 44.58 mm when its form in the same region was crowding (p=0.032). Regarding the relationship between the form and occlusion of dental arch, crowding was most common when there were class I, II and III of malocclusion both in the maxillary and mandibular.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.45-54
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• 2006

Recent beauty trends have caused an increase in the number of bialveolar protrusion patients seeking treatment of lip protrusion. But studies of these patients are not common. Studies using their dental models are especially rare. Dental models have been measured manually or through a computer by digitizing two dimensional images of models. Nowadays, we are able to study dental models more easily and accurately by utilizing the three-dimensional (3-D) laser scanner in dentistry. An investigation was carried out to evaluate the characteristics of the dental arch in a bialveolar protrusion group in comparison with a normal group using 3-D digital models. The normal group was composed of 20 subjects who were selected from students of the School of Dentistry, Kyungpook National University. The bialveolar protrusion group was composed of 20 subjects who visited for treatment at the Department of Orthodontics, Kyungpook National University Hospital. Tooth size, arch width and arch length were measured digitally, and arch shape and the shape of the palate were drawn. Based on the results of this study, the differences of the arch characteristics in the bialveolar protrusion group were that the size of the teeth was larger, mandibular canine width and 1st premolar width were wider, and arch length was longer than in the normal group. And there were differences in the arch shape and the shape of palate between the bialveolar protrusion and normal groups.

• The Journal of Advanced Prosthodontics
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• v.9 no.5
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• pp.321-327
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• 2017

PURPOSE. The aim of this study was to investigate dental arch dimensions and to classify arch shape in Korean young adults. MATERIALS AND METHODS. The sample included 50 Koreans with age ranging from 24 to 32 years. Maxillary and mandibular casts were fabricated using irreversible hydrocolloid and type III dental stones. Incisor-canine distance, $incisor-1^{st}$ molar distance, $incisor-2^{nd}$ molar distance, intercanine distance, $inter-1^{st}$ molar distance, and $inter-2^{nd}$ molar distance in both the maxillary and mandibular arch were measured using a three-dimensional measuring device. The dental arch was classified into three groups using five ratios from the measured values by the K-means clustering method. The data were analyzed with one-way analysis of variance. RESULTS. Arch lengths (IM2D, $incisal-2^{nd}$ molar distance) were 44.13 mm in the maxilla and 40.40 mm in the mandible. Arch widths (M2W, inter $2^{nd}$ molar width) were 64.12 mm in the maxilla and 56.37 mm in the mandible. Distribution of the dental arch form was mostly ovoid shape (maxilla 52% and mandible 56%), followed by the V-shape and the U-shape. The arch width for the U-shape was broader than for the other forms. CONCLUSION. This study establishes new reference data for dental arch dimensions for young Korean adults. The most common arch form is the ovoid type in the maxilla and mandible of Koreans. Clinicians should be aware of these references and classify arch type before and during their dental treatment for effective and harmonized results in Koreans.

• The korean journal of orthodontics
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• v.17 no.2
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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.

• The Journal of Korean Academy of Prosthodontics
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• v.14 no.1
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• pp.22-25
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• 1976

The author has performed a statistical study on the vertical and horizontal distance between maxillary central incisors and incisive papilla, the maxillary intercanine width, and the form of maxillary dental arch. Stone models of maxillary dental arch were made in 403 Korean adults (300 male, 103 female) from 20 to 30. years of age. The results were as follows; 1. The vertical distance between maxillary central incisors and incisive papilla was 6.0mm.. 2. The horizontal distance between maxillary central incisors and incisive papilla was 9.0mm.. 3. The maxillary intercanine width was 37.7mm.. 4. The U type of maxillary dental arch was the greatest percentage with 68.2 %, the percentage for O type was about 21.4% and the V type 10.4%.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.91-97
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• 2007

Loads on the pillar and ground deformation in 2-arch tunnel, which is excavated in the rock mass with regular discontinuities, depending on the dips of discontinuities and the construction sequences were experimentally studied. Large scale model tests in the biaxial test facility were performed. Tested model (width 3.3m, height 3.0m, and length 0.45m) for 2-arch tunnel in 1/10 scale were built with various dips. Test results show that discontinuities have greate affects on the behavior of the 2-arch tunnel, especially on the pillar loads and ground deformation.