• The korean journal of orthodontics
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• v.21 no.3
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• pp.481-493
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• 1991

The purpose of this study was to obtain the norm of the crown shape (tip, torque, in/out) and arch form, and to provide basic data for fabricating straight wire bracket and ideal arch wire for Korean. 100 subjects aged from 17 to 26 (50 females, 50 males) were selected with a normal occlusion. By measuring the size, angulation, inclination, arch width, facial prominance of the teeth and the molar offset, the following results were obtained. 1. Average, standard deviation, minimum, maximum of each measuring item for each teeth were obtained. 2. Intermolar width (${\underline{6}}$ to ${\underline{6}}$) of upper arch before occlusal surface cutting and intermolar width of upper arch (${\underline{6}}$ to ${\underline{6}}$, ${\underline{7}}$ to ${\underline{7}}$) after occlusal surface cutting showed statistical difference. There was no difference between sexes in any other measuring items. 3. Arch form and specification of straight wire bracket for Korean who have normal occlusion was obtained.

• 대한치과교정학회:학술대회논문집
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• 2003.10a
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• pp.29.2-29.2
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• 2003

• The korean journal of orthodontics
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• v.26 no.3
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• pp.281-290
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• 1996

Determination of force system and prediction of side effects from unbent straight wire engaged in edgewise bracket is clinically very difficult because it is statically indeterminate system. This study is to develop a linear beam theory that explains the force system for straight wire engaged in edgewise bracket regardless of geometry(a/b), material, cross section of wire, and interbracket distance. 1. Formula for force system of bilateral fixed end beam was derived. 2. It is possible to calculate force system of each tooth engaged in continuous straight wire. 3. The possibility and location of permanent deformation can be predicted.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.155-165
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• 1986

Recently, straight-wire appliance is widely used with great concern in clinical orthodontic field. The purpose of this study was to collect the information of the straight-wire appliance and to determine the crown inclination in clinical orthodontics. The author analyzed the study model of 78 individuals with normal occlusion. The obtained results were as follows. 1. Mean, maximum value, minimum value and standard deviation of crown inclination of upper and lower teeth were obtained. 2. The lingual crown inclination of upper tooth had constant value from first premolar through second molar, the lingual crown inclination of lower tooth progressively increased from canine through second molar. 3. As Howes' ratio was decreased, the crown inclination of upper incisors was increased. 4. Narrowing the upper arch, the crown inclination of upper incisors was increased.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.495-500
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• 1991

To design the acceptable prejusted bracket for Korean using straight wire appliance, teeth and dental arch of Korean were studied and brackets were made. It was named Oriental Bracket. The results were following. 1. The bracket position for Korean occlusion was obtained. 2. The axial inclinations of each tooth were obtained. 3. The crown torques of each tooth were obtained. 4. The thickness of each tooth was obtained. 5. The bracket (Oriental bracket) was made according to these data.

• The Journal of the Korean dental association
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• v.37 no.7 s.362
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• pp.530-535
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• 1999

Detailed finishing of the occlusion is a clinical skill that has become difficult with the development of fixed appliances. Accuracy of bracket placement definitely improves with indirect technique, Several methods for the placement of orthodontic brackets on dental casts are currently used in the indirect bonding technique. These include attachment by means of bonding resins, adhesive tapes or sticky wax. This article presents the indirect procedures of our clinic, which use paste-paste chemically cured composites. Detailed laboratory and clinical procedure for dual tray method and other application of indirect bonding will be presented.

• The korean journal of orthodontics
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• v.48 no.4
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• pp.236-244
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• 2018

Objective: The aim of this study is to compare the adaptation of a straight wire between brackets positioned at the mid-lingual surface and those placed gingivally by using a three-dimensional simulation software. Methods: This cross-sectional study was performed using OrthoAid, an in-house software. The subjects were 36 adolescents with normal Class I occlusion. For each dental cast, two bracket positioning approaches, namely the middle and gingival, were examined. In the middle group, the reference points were placed on the mid-lingual surface of each tooth, while in the gingival group, the reference points were positioned lingually on the anterior teeth. A 4th degree polynomial was adopted, and the in-plane and off-plane root mean squares (RMSs) of the distances between the reference points and the fitted polynomial curve were calculated using the software. Statistical analysis was performed using the paired-samples t-test (${\alpha}=0.05$). Results: The mean in-plane RMS of the polynomial curve to the bracket distance in the gingival group was significantly lower than that in the middle group (p < 0.001). The off-plane RMS was higher in the gingivally positioned brackets in the maxilla than in the middle group (p < 0.001). However, the off-plane RMS in mandible was not statistically significantly different between the two groups (p = 0.274). Conclusions: The results demonstrated that the gingival placement of lingual brackets on the anterior teeth could decrease the distance between a tooth and the straight wire.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.673-688
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• 1999

This study was conducted in order to analyze the mechanical characteristics of multiloop edgewise archwire (MEAW). The purposes were 1) to compare load deflection rate (LDR) of MEAW with that of various other arch wires in the individual interbracket span, 2) to compare the wire stiffness in the interbracket span with that in the multi-L-loop region (the span from distal border of the bracket of the lateral incisor to the mesial border of the buccal tube of the second molar), and 3) to verify the experimental results with theoretically derived formula. The single L-loops of five different horizontal lengths and multi-L-loops for the upper and lower arches were made out of .$016\times.022$ permachrome stainless steel wire. Straight segment of plain stainless steel, TMA and NiTi wire of the same dimension were prepared. The LDR was measured using Instron model 4466 with the load cell of 50N capacity at cross head speed of 1.0mm/min, and maximum deflection of 1.0mm. Five specimens were tested under each experimental condition. The wire stiffness number for each interbracket region and multi-L-loop region was calculated from the LDR and the interbracket spans. By dividing the theoretical model of multi-L-loop into 35 linear segments, the energy stored in each segment was obtained. Then the LDR and wire stiffness of single L-loop and multi-L-loop were calculated and compared. The findings were as follows : 1) The average LDR of MEAW in the individual interbracket region was 1/1.53 of that of the NiTi,1/2.47 of TMA and 1/5.16 of the plain stainless steel wire. 2) The wire stiffness of MEAW in the multi-L-loop region was 1.53 times larger than that in the interbracket region, and the LDR was almost twice as large as that of NiTi in that region. 3) According to the theoretically derived equation, the wire stiffness of the single L-loop was lower than that of multi-L-loop. The results of this study suggest that MEAW has the unique mechanical Property which could allow individual tooth movement and transmit elastic force effectively through the entire arch wire.

• The korean journal of orthodontics
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• v.16 no.2
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• pp.123-133
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• 1986

The purpose of this study was to collect the information of the straight-wire appliance and to determine the amount of second-order bends in clinical orthodontics. The author analysed the study model of 50 individuals with normal occlusion and results were obtained as follows. 1. The crown angulation was 4 degree in upper central incisor, 7 degree in upper lateral incisor, and 0 degree in lower central incisor and lateral incisor. 2. The crown angulation was 8 degree in upper cuspid and 2 degree in lower cuspid. 3. The crown angulations were 4 degree in upper first bicuspid, upper second bicuspid and lower second bicuspid and 1 degree in lower first bicuspid. 4. The crown angulation was 3 degree in upper first molar, 0 degree in upper second molar, 5 degree in lower first molar and 8 degree in lower second molar. 5. The crown angulations in lower arch were progressively increased from first premolar to second molar. 6. In upper arch, as the crown angulation of one tooth was increased, those of adjacent teeth were increased, too. 7. In the case of lower arch, the crown angulation of cuspid was increased as that of lateral incisor was increased, the crown angulation of second premolar was increased as that of first premolar was increased, and similarity the crown angulation of second molar was increased as that of first molar was increased.

• The korean journal of orthodontics
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• v.12 no.1
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• pp.31-36
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• 1982

20 years old female patient with asymmetric mandibular prognathism had anterior openbite, anterior cross-bite and mandibular shift. This patient was treated with both orthodontic and surgical method. Maxillary second molars were extracted to reduce the wedging effect and maxillary first molars moved to distal by straight pull head gear. After orthognathic surgery, open-bite was corrected with multiple shoe-loop arch wire.