• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.885-895
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• 1994

This study was performed to compare the dental arch dimensions of urban and rural high school females according to the region of residence and facial type. A model and cephalometric analysis was made from 48 urban and 48 rural high school females. The results of this study were obtained as follows : 1. Arch width in the urban group were similar to the rural group. 2. Lingual arch length at upper 1st premolar level in the urban group was larger than the rural group and lingual arch length at lower canine level in rural group was larger than the urban group. 3. Palatal height at canine level in the rural group was higher than the urban group. 4. Palatal heights at 2nd premolar and 1st molar level had correlation with the VERT index. In comparison of lingual arch dimensions according to Rickett's facial group, palatal heights at 2nd premolar and 1st molar level in dolichofacial group were lower than other groups.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.95-108
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• 1982

The purpose of this study was to analyze the growth and development of tooth germ and dental arch related to the bone growth during the fetal period. From 70 maxillae and 61 mandibles of the fetus aged 5, 6, 7, 8, 9 and 10 months, X-ray films were taken and measured. The results were as follows; 1. There was remarkable bone growth in the anterior and posterior area of palatum osseum, that were the intetior portion of both deciduous canines anteriorly and the intero-posterior portion of both deciduous second molars posteriorly, where there was active bone growth and radiate formation of bony trabeculae was found. 2. The Growth of anterior tooth germ was greater than that of posterior tooth germ, so anterior tooth germs were crowded. Especially in maxilla, the tooth germs of deciduous lateral incisors were located inside of dental arch and the tooth germs of deciduous canines were located outside of dental arch. 3. Crowding amount increased with the fetal age because the growth of tooth germs was greater than that of jaw bone. 4. In the growth of upper dental arch, the increase of width was greater than that of length. 5. There was proportional relationship between the area of Palatal Trapezoid and the fetal age.

• Journal of Oral Medicine and Pain
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• v.5 no.1
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• pp.5-10
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• 1980

Numerous investigators have pointed out that the force of the tongue against the teeth within the dental arches is normally compensated for by the action of the musculature of the cheeks and lips, and that the tongue at rest occupies a large part of the oral cavity. The purpose of this study was to estimate the maximum areas of the tongue movement by measuring the inner area of the dental arches of both the maxilla and the mandible. This study was based on the study models of 30 children and 128 adults who had clinically good occlusion. There were 15 male and 15 female children whose ages ranged from four years to seven years and 82 male and 46 female adults whose ages ranged from fifteen years to fifty four years. The obtained results were as follows : 1. The mean of the maximum areas within the primary dental arches of both the maxilla and the mandible were $7.06\pm0.8\textrm{cm}^2, 5.49\pm0.77\textrm{cm}^2$ in male children and $6.82\pm0.98\textrm{cm}^2, 5.28\pm0.80\textrm{cm}^2$ in female children respectively. 2. The mean of the maximum areas within the permanent dental arches of both the maxilla and mandible were $17.01\pm2.38\textrm{cm}^2, 13.57\pm1.57\textrm{cm}^2$ in male and $16.75\pm2.08\textrm{cm}^2, 13.36\pm1.01\textrm{cm}^2$ in female respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.569-578
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• 2004

The purpose of this study was to clarify the palatal arch length, width and height in the primary and permanent dentition. Samples were consisted of normal occlusions both in the primary dentition(50 males and 50 females) and in the permanent dentition(50 males and 50 females). With their upper plaster casts were used and through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), cloud data, polygonization, section curve and loft surface, fit and horizontal plane were based to measure the palatal arch length, width and height(Surfacer 10.0, Imageware, U.S.A.). T-tests were applied for the statistical analyze of the data. The results were as follows : 1. In the measurement values, the values of the male were higher than those of the female except primary anterior palatal height. There were not only statistically significant differences in anterior palatal width(p<0.05) and posterior palatal width(p<0.01) in primary dentition but palatal width(p<0.05), anterior palatal length(p<0.01), middle and posterior palatal length(p<0.05) in permanent dentition between male and female. 2. In the indices of palate, there were statistically significant differences in height-length index(p<0.05) and width-length index(p<0.01) between male and female in primary dentition. In permanent dentition, there was statistically difference between male and female. 3. In the measurement values, posterior palatal width was increased most greatly. Posterior palatal height, anterior palatal width and anterior palatal length were followed by descending order. On the other hand, anterior palatal height and posterior palatal length were decreased. 4. In the indices of palate, the height-length index, the width-length index and posterior height-width index were increased, but the others were decreased.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.685-693
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• 2007

Class I malocclusion without skeletal problem results from tooth size/arch-size discrepancies, either evidenced by crowding, or spacing problems. Treatment method can be chosen according to dentition, the amount of arch discrepancy, patient compliance, or patient demands. We report of clear aligner and spring aligner that can be applicated in cases of permanent dentition with minimal arch discrepancy in anterior segment. There are some limits of application, but these are very useful appliances in the selective case. When crowding exists, definitive analysis and diagnosis should be made before starting treatment because certain amount of space must be obtained somewhere in the dentition to resolve the crowding. Therefore, appliance should be applied when lacking space is small. Also, in cases with spacing arch circumference is reduced after alignment so no problem in intermaxilla occlusal relationship must be confirmed. In case with crowding, judicious removal of interproximal enamel is indicated.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.507-512
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• 1999

In the mixed dentition, many children have mild crowding of anterior dentition on the mandibular arch and mesial tilting of mandibular molar. Lip bumper have been used to gain arch length for the alignment of mild to moderate crowded dental arches. As such, they may provide an alternative to extraction therapy. The claimed therapeutic effect of the lip bumper is bodily forward incisor movement, flaring of the lower incisors, and distal tipping of the molar. The dental changes can be attributed to removal of lip pressure on the lower anterior dentition and the distal forces exerted at the molar abutment. The purpose of this study is to show more easily method of treatment for mild anterior crowding of mandible.

• Korean Journal of Cleft Lip And Palate
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• v.4 no.2
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• pp.9-18
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• 2001

Cleft lip and palate is the most frequent congenital facial deformity of the orofacial area. Successful management of patients with cleft lip and palate requires a multidisciplinary approach from birth to adult stage. The early surgical intervention of lip and palate induces a significant incidence of maxillary growth restriction that produces secondary deformities of the jaws, and the severity of the skeletal discrepancies tends to increase with growth. The early growth modification treatment to utilize the patient's growth potential is necessary in the cleft lip and palate patients, and we must consider not only the existing skeletal discrepancies but the residual growth amount and the direction. However, once we have obtained good results with orthopedic treatment in mixed dentition stage, we must pay special attention to maintain the treatment results because of high relapse tendencies and the alterations of jaw relationships due to residual growth.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.815-824
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• 1997

The purpose of this study is to develop the basic algorithm for the finite element method modeling of individual malocclusions. Usually, a great deal of time is spent in preprocessing. To reduce the time required, we developed a standardized procedure for measuring the position of each tooth and a program to automatically preprocess. The following procedures were carried to complete this study. 1. Twenty-eight teeth morphologies were constructed three-dimensionally for the finite element analysis and saved as separate files. 2. Standard brackets were attached so that the FA points coincide with the center of the brackets. 3. The study model of a patient was made. 4. Using the study model, the crown inclination, angulation, and the vertical distance from the tip of a tooth was measured by using specially designed tools. 5. The arch form was determined from a picture of the model with an image processing technique. 6. The measured data were input as a rotational matrix. 7. The program provides an output file containing the necessary information about the three-dimensional position of teeth, which is applicable to several finite element programs commonly used. The program for a basic algorithm was made with Turbo-C and the subsequent outfile was applied to ANSYS. This standardized model measuring procedure and the program reduce the time required, especially for preprocessing and can be applied to other malocclusions easily.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.487-495
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• 1996

The purpose of this study was to evaluate the dentofacial characteristics and the fost-treatment dentofacial changes of those treated by four premolar extractions and to investigate the factors affecting extraction decision. The sample consisted of 35 patients (27 females, and 8 males) with no more than 7.0mm crowding, diagnosed as Class I protrusion. Pre-treatment and post-treatment lateral cephalograms were evaluated. Computerized statistical analysis was carried out using SPSS/PC+ program. The results were as follows. 1. There was no significant change in skeletal pattern after treatment while there was significant change in dentoalveolar and soft tissue pattern. 2. In pre-treatment skeletal pattern, a tendency toward vertical discrepancy was found. 3. In pre-treatment dental pattern, interincisal angle was $113.11^{\circ}$, U1 to FH was $117.78^{\circ}$ and L1 to A-Pog was 7.94mm. Pre-treatment upper and lower lip position was 2.88mm and 5.43mm to E line. 4. After treatment, interincisal angle increased $14.46^{\circ}$ and upper and lower lip moved back 2.45mm and 3.2mm to E line.(p<0.001) 5. The EI was 138.71 before treatment and 148.2 after treatment.

• The korean journal of orthodontics
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• v.14 no.1
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• pp.93-101
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• 1984

Human dental arches are very various in their sizes and dimensions as well as forms, so, it is very difficult to describe the shape of human dental arches as a criterion, and, further, to construct the preformed arch wires fit to them. In this study for solving these problems, the shape of eighty Korean normal lower dental arches were studied, and nine theoretical two-parameter catenary curves were derived, which were representative of all of the sample. Test were conducted which demonstrated that these nine cattenary curves would correspond with a reasonable degree of accuracy to all of the dental arches, lower and upper.