• The korean journal of orthodontics
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• v.31 no.3 s.86
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• pp.347-355
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• 2001

Maxillary and mandibular anterior dental arches often have the problems of occlusal relation and esthetics by malformations of teeth, congenital missing, et at. Though the clinician usually use the anterior ratio to overcome this problems, he has the limitation of a direct application this ratio to the prediction of anterior occlusal relationship by the change of anterior ratio as dental arch form, intercanine width, segment depth and arch perimeter. So this study examine maxillary and mandibular anterior dental arch forms by least square method using Korean normal occlusion models(man : 20 casts, woman : 20 casts). Maxillary and mandibular anterior dental arches of Korean normal occlusion models are curve fitted to polynomial function, beta function, hyperbolic cosine function in order. And this accuracy of curve fitting is constant regardless of man/woman and maxilla/mandible. The relationships between intercanine width, segment depth, and arch perimeter based on this owe fitted dental arch form are acquired. This relationships will give the prediction of anterior dental arch form and the information of more accurate anterior ratio according to intercanine width.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.1
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• pp.55-65
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• 2024

This study aimed to assess the accuracy of tooth widths, intermolar widths, and arch lengths acquired through two intraoral scanners, including iTero Element Plus Series (Align Technology, Santa Clara, CA, USA) and Trios 4 (3Shape, Copenhagen, Denmark), specifically on mixed dentition. A total of 30 subjects were divided into 2 groups, each undergoing both alginate impressions and intraoral scanning using either the iTero or Trios scanner. The plaster models were measured with a caliper, while the digital models were measured virtually. In the iTero group, all tooth width measurements exhibited differences compared to the plaster values, except for maxillary left lateral incisors (p = 0.179), mandibular right (p = 0.285), and left (p = 0.073) central incisors. The Trios group did not display significant differences in any of the tooth width measurements. Intermolar width comparisons for both groups indicated differences, except for mandibular primary canine to primary canine values (p = 0.426) in the iTero group. Regarding arch length, the mandibular anterior, maxillary right, and left arch lengths in the iTero group demonstrated larger caliper values than those of iTero. Conversely, in the Trios group, all parameters showed smaller caliper values, especially in upper anterior, maxillary right, mandibular right, and mandibular left arch lengths with significance (p = 0.027, 0.007, 0.003, and 0.047, respectively). Despite the differences between the two groups, digital models might be clinically suitable alternatives for plaster models. Pediatric dentists should carefully assess these differences, as a comprehensive evaluation would result in precise orthodontic treatment planning and favorable outcomes for young patients with mixed dentition.

• The korean journal of orthodontics
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• v.33 no.2 s.97
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• pp.85-90
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• 2003

The symphyseal mandibular fractures due to accidents happened in form of collapsed transeverse arch and multiple teeth loss. And the collapsed transverse arch in mandible occurs with unilaterally or bilaterally. So that patient needs to recover arch width. Conventional approaches, however, we difficult to get appropriate transverse arch correction. Distraction osteogenesis is a unique form of clinical tissue engineering and biologic process of new bone formation between bone segments that are gradually separately by incremental traction. Distraction osteogenesis is considered that great potential for correcting transverse mandibular deficiencies. Tn this paper, distraction osteogenesis applied to patients who had a unilateral or bilateral collapsed arch width in mandible. But it was necessary secrutinize consideration about periodontal conditions, biomechanical vectors, TMJ adaptations, and neuromuscular change during distraction osteogenesis period.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.115-126
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• 2000

Dental arch expansion is one of the method used to solve the dental crowding problem by non-extraction. Many formulae using tooth size have been suggested to predict ideal inter-premolar and inter-molar width. The purpose of this study was to evaluate the adequacy of some upper dental arch width prediction methods, namely Pont's method, Schmuth's method and Cha's method. The sample consisted of the casts of 119 Korean young adults who had no muscular abnormality, no skeletal discrepancy, and Angle's Class I molar relationships. Measurements were obtained directly from plaster casts; they Included mesiodistal crown diameters of the four maxillary incisors, as well as maxillary inter-first-premolar and inter-first-molar arch widths as specified by Pont. The correlation coefficients between the sum of incisors(SI) and upper dental arch width were calculated. The differences between predicted width and actual width were classified as overestimated, properestimated, and underestimated. The data obtained from each group were analyzed for statistical differences. The results were as follows : 1. Upper dental arch width indices were calculated from SI in normal occlusion (81.96 : premolar index, 62.55 : molar index). 2. Low correlations between SI and arch width were noted in normal occlusion (0.50 in the inter-premolar width, 0.39 in the inter-molar width). 3. Pont's formula and Schmuth's formula tended to overestimate the inter-premolar width. A more even distribution of estimates was noted in Cha's fomula. 4. Cases within $\pm$1 mm range of observed inter-premolar width were $45\%$ in the Cha's formula, $40\%$ in the Pont's formula, and $39\%$ in the Schmuth's formula. 5. All formulae had a tendency to underestimate the inter-molar width, but Cha's formula had better predictability than others. 6. Cases within $\pm$1 mm range of observed inter-molar width were $40\%$ in the Cha's formula, $29\%$ in the Pont's formula, and $13\%$ of Schmuth's formula. The data presented in this study does not support the clinical usefulness of ideal arch width prediction methods using the mesiodistal width of maxillary incisors.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.365-374
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• 1996

The prupose of this study was to obtain standard measurements of the tooth size, Bolton ratio, width and length of dental arch and basal arch, overbite and overjet of the children who have normal dentition. The plaster cast of 97 children(47 boys and 50 girls) among the contestants in 1992, 1994, 1995 Healthy Dentition contest in Seoul were measured and following results were obtained. 1. Means and standard deviations of the mesio-distal maximum width of the permanent teeth, Bolton ratio, width and length of the dental arch and basal arch of the upper and lower dentition and overbite and overjet of the children were obtained. 2. Mesio-distal width of the teeth, width and length of the dental arch and basal arch of the upper and lower dentition of the boys were larger than those of the girls. 3. Bolton Overall ratio, Anterior ratio and overjet of the boys were larger than those of the girls and overbite of the boys were smaller than those of the girls, but no significant differences were noted between the boys and the girls(p>0.05). 4. In the comparision of the Healthy Dentition Contestants with Korean adults of Shur, all teeth of the Contestants were larger than those of Korean adults, especially upper and lower bicuspids(p<0.01). In the comparision of the Healthy Dentition Contestants with Caucasians, all teeth except upper and lower central incisor and upper first molar of the contestants were larger than those of Caucasians(p<0.05).

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.95-106
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• 1989

This study was designed to investigate dental arch shapes buccally and lingually at Bracket Level of Koreans. This involved studying 63 inviduals (37 males, 26 females) with normal occlusion ranging in age from 17 to 24 years old. The landmarks were digitized and measurements and statistical analysis were performed by NEC 9801 V-M computer. The Results were as Follows: Bicanine width, Bipremolar width and Bimolar width were larger in males than in females. Buccal and lingual arch form and coordination form were obtained by NEC 9801 V-M computer. The parabolic equations which represents buccal and lingual arch form were obtained.

• 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 Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.131-141
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• 1989

This study was designed to investigate the fitness of stock tray in Korean adults. 107 dental students (male: 87, female: 20) who have normal occlusion and symmetric facial fom were selected. The upper and lower stock tray (Osungtray, Osung Co., Korea) fit with dental arch were selected for taking irreversible hydrocolloid impression. The author measured the thickness of impression material about two items, that is, width and length on the flange of stock tray. Several measuring points on the dental arches and palatal area were checked with Goldman Fox prove (Hu-Friedy, U.S.A.). The obtained results were as follows: 1. The width of impression material on buccal flange of upper and lower trays were narrower than any other measuring point, but the thickness of impression material on the palatal area of upper stock tray was the widest of all measuring points. 2. The length on buccal flange of lower stock tray was shorter, but the length on tray flange of lower stock tray at lingual frenum area was longer. 3. On upper dental arch, the upper extra-large tray was used in 53% of subjects, but upper small tray was not used. 4. On lower dental arch, the large tray was used in 55% of subjects. 5. There was not adequate tray on upper dental arch in 4 subjects.