• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.323-328
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• 2001

Anterior open bite is one in which the teeth in the anterior portion of the maxilla and mandible are vertically apart and lack the overlapping necessary for the incisive function when the mandible is in closed position. Anterior open bite is a result of the interaction of many different etiologic factors including thumb and finger sucking, lip and tongue habits, airway obstruction, skeletal growth abnormalities and its tendency may appear with any type of skeletal patterns, such as Class I, II or III malocclusion types. Though the treatment methods for anterior open bite are various, the conventional FR-4, designed by Rolf Fr$\"{a}$nkel, is known to be effective in treating open bite cases with Class I or II skeletal patterns. It is due to that an incidence of skeletal Class II is high in the Occidentals, and open bite is accompanied by these malocclusion type in many cases. However, an incidence of skeletal Class III is high in the Orientals, and open bite is sometimes accompanied by skeletal Class III in many cases. Although the use of the conventional FR-4 was effective in the treatment of open bite, skeletal Class III would be worsened. So, a modified FR-4(placing the labial bow in the lower, the labial pads in the upper) was designed for the treatment of patients showing skeletal Class III and open bite.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.163-173
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• 2018

This study was carried out to propose the baseline data for in situ conservation by analyzing environmental and growth characteristics in Pedicularis hallaisanenesis habitats. P. hallaisanensis habitats, according to investigations, were located on the slope of southwest at an elevation of 1,400 m in Mt. Gayasan and on the slope of southeast at an elevation of 1,500 m in Mt. Hallasan. Pedicularishallaisanensis habitats. Also, habitats were found at the grassland with no upper vegetation. In the study sites, soil pH and soil organic matter were 4.9-6.5 and 4.4-8.1%, respectively. A total of 55 vascular plants taxa were identified in ten quadrats in two habitats, of which 25 were inhabited in Mt. Gayasan and 37 in Mt. Hallasan. Current status of P. hallaisanensis habitats were very vulnerable with the pressure of the vegetation constantly threatening the species' survival. Thus, concrete conservation plans including diverse factors as light intensity, temperature and genetic analysis to protect natural habitats should be set up as soon as possible.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.123-133
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• 1990

The work was undertaken to evaluate the calcification of the second and the third molars in skeletal Class II and III malocclusions. The differences in the calcification stages between skeletal Class II and III malocclusion were evaluated and statistically analysed from panoramic radiographs of 202 males and females ranging in age from 11 to 15 years old. The results were as follows, 1. The calcification stages of the second and the third molars were not different between the skeletal Class II and III malocclusions in each age groups of both sexes. 2. The calcification stages of lower second and third molars of the skeletal Class III malocclusion are more advanced than those of the skeletal Class II malocclusion in male. 3. The clacification stages of upper second and third molars are more advanced than those of lower second and third molars in skeletal Class II malocclusion. 4. The calcification stages of lower second and third molars are more advanced than those of upper second and third molars in skeletal Class III malocclusion.

• IE interfaces
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• v.23 no.3
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• pp.221-228
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• 2010

With the development of science and technology, modern submarines are equipped with high technology devices and multi-functioned precise armaments, consequently, acquisition cost as well as maintenance cost of the submarines are getting higher and higher. However, tight defense budget forces navy to significantly reduce military operating and maintenance costs. In this study, the maintenance and operating costs of submarine Jangbogo-II are estimated through M&S (Modeling and simulation) methodologies in order to reasonably and consistently work out the requirement verification system of Jangbogo-II. The maintenance and operating costs of Jangbogo-II along the next 25 years are estimated as 312.65 billion won via engineering analysis methods while 312.69 billion won from PRICE Model, which shows only 0.04 billion won differences as a whole. This study is expected to be able to provide meaningful decision making data for not only short and/or mid term operating planning but military budgeting.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.577-585
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• 1994

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a $45^{\circ}$ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed: 1. Large overjet and deep overbite were corrected. 2. Class II molar relationship was changed into Class I. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

• Journal of Yeungnam Medical Science
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• v.4 no.1
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• pp.151-156
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• 1987

A 25 year and 7 month old man patient who had Angle's classII division 2 malocclusion combined with anterior crowding of upper & lower part was treated by bioprogressive mechanism. After setting our objectives through the use of V.T.O., we programmed a sequence of mechanics. The possible objectives of treatment in the classII division 2 malocclusion can be listed as follows. 1) Relief of crowding & irregularities. 2) Relief of anterior gingival trauma & correction of interincisal inclination. 3) Correction of buccal segment relationship. We'd applied the classII intermaxillary elastics, Quad helix, utility arch wire and sectional arch wire in order to achieve anticipated objectives. As compared with pre & post treatment cephalogram, the result accomplished by this mechanics showed to us that interincisal angle was improved and favorable molar relationship was achieved.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.145-153
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• 1989

The causes of the missing teeth are classified as congenital missing, trauma and extraction due to dental caries, variable problems are occured clinically by the missing teeth. The missing of the upper incisors especially would assume a serious aspect, and could be treated by three methods of orthodontic treatment, prosthodontic treatment and autotransplantation of the premolar teeth. The patient of this report had the skeletal class II malocclusion with the left upper central incisor missing, and have been treated with the fixed appliance after extraction of the right upper central incisor and both lower second premolars. The results were obtained as follows: 1. Treatment was done for 1 year 6 months. 2. Normal overbite and overjet were achieved. 3. Cuspal interdigitation was obtained normally. 4. Space problem was resolved with resin restoration of the upper lateral incisors. 5. The upper canines were used as the upper laterals after cuspal contouring. 6. Retention would be required with adequate retainers for a long time to prevent relapsing after treatment.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.167-177
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• 1986

This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.

• The korean journal of orthodontics
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• v.21 no.1 s.33
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• pp.171-183
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• 1991

This investigation was designed to categorize Angle's class II malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class II malocclusion. The material selected for this study consisted in standard lateral cephalogram of two hundred and twenteen children, eighty eight boys and one hundred twenty four girls, aged 6 through 18 years, having Angle's class II malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications, 16 groups were classified according to FMN-A-B, SE-FMN-A, Ba-SE-Me, Ba-Se/Ra P. The sequences that have relatively high frequency are as follows: a) Horizontal Group 16 b) Horizontal Group 12 c) Horizontal Group 13 d) Horizontal Group 9 & 15 2. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/Occ. P. PMV/Mn. P. The sequences that relatively high frequency are as follows; a) Vertical Group A b) Vertical Group D c) Vertical Group C d) Vertical Group H 3. In vertical and horizontal skeletal classifications, the sequence that relatively high frequency are as follows; a) Group13-A b) Group16-A & 9-A c) Group12-A & 15-A d) Group16-C

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.