• 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.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.29-34
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• 2006

This study was undertaken to compare the tooth and arch size between crowding patient and normal subjects. Two group of dental casts were selected on the basis of crowding patients and normal subjects. One group, consisting of 40 pair of dental casts(20 male and 20 female), exhibited noncrowded dentitions. A second group, consisting of 40 pairs of dental cast(21 male and 21 female), exhibited remarkably crowding need for orthodontic treatment. Tooth width measurements were made with a sliding digital caliper with Vernier scale neared 0.01 mm. Mean, standard deviation, T-test of the following parameters were used to compare two group : individual mesiodistal crown widths, arch width and arch length. The following result were obtained. In the mesiodistal crown widths, normal subjects had generalized larger teeth than Wheeler's results(human tooth size index), except for maxillary central incisor, maxillary 2nd premolar, mandibular canine, and mandibular 1st molar. In the orthodontic patients with crowded dentitions, the mesiodistal tooth crown widths were generalized larger teeth than noncrowded normal subjects. In the arch width and arch length, the crowded dentition group had smaller arch width and arch length than the normal group.

• 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.26 no.3
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• pp.225-239
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• 1996

This study was carried out as a part of the semi-longitudinal study on growth and development of Korean children, with purpose of observing the growth change in arch form., 736 pairs, of study models were taken for 3 years. Mesio-distal diameter of each tooth, intercanine width, intermolar width, canine arch depth, molar arch depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and corresponding graphs were drawn. The following conclusions were obtained : 1. Mesio-distal diameters of maxillary central incisor, maxillary 2nd molar, mandibular canine, and mandibular 2nd molar showed statistical difierences between boys and girls. 2. Intercanine width shows a gradual increase until age of 11. 3. Intermolar width in maxilla shows continuous increase, and the tendency of increase is more apparent between age of 9 and 14. In mandible, various pattern was shown until age of 9, and after, a slight increase. 4. Canine arch depth shows the increasing tendency until age of 13 in maxilla and 11 in mandible. 5. Molar arch depth shows the pattern of increase until age of 10 in male and 9 in female, which is more apparent in maxilla. After age of 9 or 10,dereasing pattrn was significantly shown until age of 15 in maxilla and age of 12 in mandible. 6. Arch perimeters in maxilla and mandible showed gradual increase until age of 10, and the tendency of increase was more apparent in maxilla; however, between the age of 10 and 14, arch perimeters of maxilla and mandible showed gradual decrease which was more apparent in mandible.

• 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.36 no.1 s.114
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• pp.84-90
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• 2006

The aims of this study were to investigate the prevalence of spaced, closed, and crowded primary dentitions by sex and arch in Korean children from Kanghwa, and to determine the frequency of the primate and developmental spaces. The differences in the mesiodistal crown diameters and the arch dimensions between the spaced, closed, and crowded primary dentitions were also evaluated. Dental casts of 102 preschool children (57 males and 45 females, aged $4{\sim}5$ years) were studied. The prevalence of spacing in the primary dentition was 63.2% In males and 57.8% in females. The frequency of spacing was greater in males than in females, and greater in the maxillary arch than in the mandibular arch. The crowns were significantly larger and the arches significantly narrower in closed and crowded dentitions than in those with spacing (p<0.05). The results showed that the prevalence of spacing was lower than that found in previous studies and the presence of spacing in the anterior region was related to the mesiodistal crown diameter and the intercanine width.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.457-471
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• 1997

The Purpose of this study was to estimate relative importance among the causative factors o( arch length discrepancy(ALD) and Possibility of prediction of the ALD in the mixed dentition. The sample consisted of the casts of the 142 young adults who had no abnormal muscle function, no skeletal abnormalities and Class I molar relationship. We classified the sample by gender and the extent of ALD, and measured mesiodistal diameters of each tooth and the dimensions of the dental arch. The computerized statistical analyses was carried out with SPSS win program. The results were as follows ; 1. Most of the variables of spacing group and some variables of dental arch dimension of crowding group were significantly different between genders. But in normal group, there were few differences. 2. In male crowding and female spacing group, mainly measurements of tooth dimension were significantly different from those of normal group. 3. In male spacing and female crowding group, measurements of dental arch dimension were significantly different from those of normal group. 4. The measurements of dimension of dental arch were highly correlated with ALD in correlation analysis and factor analysis. 5. Prediction equations for adult's ALDs by means of what can be measured in the mixed dentition(mesiodistal dimensions of incisors and first molar, intermolar width and arch length) showed R square from $63\%$ to $80\%$.

• 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.34 no.6 s.107
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• pp.473-480
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• 2004

The aim of this study was to establish normative data on the tooth size and arch parameters of Koreans with normal occlusion, This study employed the dental casts of 296 (male: 179; female 117) normal occlusion samples, who were selected from 15,836 adults through a community dental health survey. The mesiodistal diameters of teeth, arch width, and arch length were measured by digital electronic calipers(accurate to 0.01 mm) and Bolton's indices as well as intermaxillary arch width ratios were calculated. In order to ensure reliability, intra- and inter-examiner error were evaluated. Although our dimensional data showed overt differences between genders, the indices and intermaxillary ratios evaluated were the same. The resultant data obtained were compared with the previous data to reveal whether any changes have occurred over the time. The clinical implication of the present findings was also discussed. This biometric study seemed to provide a clinically applicable diagnostic criteria for an individual malocclusion patient.

• 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.