• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.475-483
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• 1993

The purpose of this study was to investigate the treatment effects on anterior crossbite patients using chin cap and labiolingual arch appliance. In the present study, I statistically evaluated measurement values on a cephalogram before and after treatment form twenty anterior crossbite cases. The results were as follows: 1. In the craniofacial patterns, cranial base increased after treatment. 2. In the maxillo-mandibular relationship, ANB and Facial convexity significantly increased. 3. In the denture patterns, occlusal plane, Ul to FH and Overjet significantly increased. On the contrary overbite decreased significantly. Lower incisors inclined lingually. 4. In the soft tissue profile changes, lower lip protrusion was signifacantly improved.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.447-454
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• 1993

Patient with skeletal class II relationship was treated with L-ARS. L-ARS is fixed functional appliance that could be effective in children and adolescent patient who don't wear activator. The following results were obtained ; 1) Growth of Mandible was stimulated and overjet was decreased, therefore coupling of anterior teeth was established with L-ARS which is fixed functional appliance. 2) These changes were accomplished with Mandibular skeletal growth with no effect on the Maxilla. 3) L-ARS was especially effective on patient who deny to wear the removable functional appliance.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.725-734
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• 1993

Nitinol wires are now widely used in the orthodontic field because of their unique shape memory effect and superelasticity. But sometimes Nitinol wires are deformed in clinical use. Fatigue load is possible cause of Nitinol deformation. To determine the effect of fatigue load to the mechanical properties of Nitinol, various fatigue cycle$(1\times10^4,\;2\times10^4,\;3\times10^4,\;4\times10^4,\;5\times10^4,\;1\times10^5)$ were applied to $0.017\times0.025$ inch Nitinol. The results obtained were as follows ; 1. Applied load increased as fatigue cycle increased in three point bending test. 2. Maximum tensile strength and elongation decreased as fatigue cycle increased. 3. Tn SEM, brittle fracture pattern was increased when fatigue cycle increased.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.861-869
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• 1994

The purpose of this study was to investigate the relationship of nose profile with respect to skeletodental pattern, by measured and analyzed statistically the lateral cephalograms of 95 females (13 to 30 years old). Tge results were summerized as follows ; 1. The antero-posterior factors of the nose - nasofrontal angle, nasofacial angle, and dorsal length / ala length ratio were different among the malocclusion groups 2. There were no significant correlation between the the vertical nose factors and the skeletal factors 3. The Class I groups had a straight nose profile , the Class II groups had a convex profile ; the Class III groups had a concave profile.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.69-73
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• 1975

This is case report of true class III malocclusion with macroglossia is corrected by glossectomy in 13 years female patient. After orthodontic treatment, the patient is bound to glossectomy because the corrected condition is relapsed to the previous condition due to relatively enlarged tongue compared with the original dental arch. By the interpretation of the cephalogram and model analysis, it is approved that the growth pattern and direction are normal range and mandible is located anterioly to the cranium. The results are follows: 1. We could treat the true Cl III malocclusion. 2. We could prevent the relapse of the treated condition by the surgical intervention, such as partial glossectomy. 3. Sensory, speech, swallowing and so other functions after the operation have been with in normal limit without any serious complications or seguellae.

• The korean journal of orthodontics
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• v.9 no.1
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• pp.117-123
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• 1979

The aspects examined in the present study concerning the location and position of the lower third molar and the interrelationships of this molar, the gonial angle, and the second lower molar in subjects aged 8-24 are based on measurements made from 472 orthopantomograms. The following conclusion were drawn on the basis of the present study. 1. The gonial angle decreased with age, but slight enlarging occurred in the age group 20-21. 2. The angulation of the third molar in relation to the second molar did not correlate with the size of the gonial angle but decreased with developmental stage. 3. The mesial angle between the longitudinal axis of the second molar and the mandibular base line correlated significantly with the gonial angle. The above angle were smaller in Class II, Divison 2 and larger in Class III than in Class I and Class II, Division 1. 4. The rate of presence of lower third molar was 74.4%.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.21-24
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• 1975

The purpose of this study was to investigate the effect of sinc phosphate cement on the enamel surface of extracted teeth. The tooth was placed in a test tube, which was subjected to 5ml of 0.2M acetate buffer at pH 4 by 'window technique.' The calcium content of the acetate buffer was determined by the Perkin-Elmer Model 303 Atomic Absorption Spectrophotometer. The obtained results were summarized in the following. 1. The solubility of enamel is $0.92mg/cm^2$. ml in control group. 2. The solubility of enamel is increased by treating these with zinc phosphate cements. 3. The solubility of enamel is $0.69mg/cm^2$. ml by treating with Lee Smith cement. 4. The solubility of enamel is $0.30mg/cm^2$. ml by treating with G-C's cement.

• The korean journal of orthodontics
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• v.9 no.1
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• pp.9-14
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• 1979

The purpose of this study was to pursue the biosynthesis of proteins of human and bovine periodontal ligaments in vitro system. The excised periodontal ligaments from human and bovine were incubated in Krebs-glucose medium containing $^3H$-proline. After incubation the incubated periodontal ligaments were homogenized and the proteins were treated with 0.1%sodium dodecyl sulfate and $\beta$-mercaptoethanol. Separation of the protein fractions was performed with agarose gel column chromatography and SDS acrylamide gel electrophoresis. The results indicated as follow: 1. Only a small percentage of $^3H$-proline incorporated into proteins was hydroxylated to $^3H$-hydroxyproline. 2. The labeled proteins in periodontal ligaments showed a wide distribution of molecular weight. But only small amounts of labeled protein were found that were characteristics of the molecular weight of collagen. 3. In all of the combined fractions of gel filtration, the degree of hydroxylation was small.

• The korean journal of orthodontics
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• v.5 no.1
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• pp.33-41
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• 1975

To study the effect of the tetracycline-HCl on the growth of the rats, the author made a daily injection of tetracycline-HCl in the amount of 40mg/kg of body weight to the lactating mother and weanling rats for 7 days. Lactating and weanling young rats were killed at a week intervals and removed tibia and mandible from soft tissues. The effect of the tetracycline on the growth of rats were analysed from the weight, the length of tibia and the size of mandible. The results were as follows: 1. Tetracycline inhibited the growth of young rats. 2. Inhibitory effects were greater ill the weanling group than the lactating group. 3. The inhibitory effect was marked just after the injection of tetracycline-HCl in body weight and after a week in mandible and tibia. 4. The inhibitory effect of growth nab continued for 2-3 weeks in body weight and 3-4 weeks in tibia and mandible. 5. In growth of mandible, the antero-posterior growth was more inhibited than the vertical.

• The korean journal of orthodontics
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• v.9 no.1
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• pp.105-110
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• 1979

In order to define what the average Class I malocclusion looks like, 72 Class I malocclusions were compared with corresponding measurements from 90 cases of normal occlusion sample. This sample was obtained from the Department of Orthodontics, Infirmary of Seoul National University. 1. SNA, Fac(NP) to SN measurements were significantly different from the normal occlusions and smaller than the normal occlusion means. 2. 'Y' axis to SN, Mandibular plane to SN, $\underline{1}$ to Occlusal plane, $\bar{1}$ to NB(linear) measurements were significantly different from the normal occlusions and larger than the normal occlusions. 3. ANB, Occlusal plane to SN, AB to Occlusal plane, $\underline{1}$ to SN, $\bar{1}$ to SN, $\bar{1}$ to Occlusal plane measurements showed no significant difference between the means.