• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.105-112
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• 1988

To predict duration of orthodontic treatment of malocclusion, 304 male and female patients whose orthodontic treatment was finished in department of orthodontics, Infirmary of dental college, Chosun University were studied. The duration of treatment was studied according to types of malocclusion, beginning ages of treatment, Hellman's dental ages, the determination of tooth extraction, types of tooth extraction and types of orthodontic appliance. The following results were obtained. 1. The duration of treatment was 18 months in Class I malocclusion, 20 months in Class II malocclusion and 24 months in Class III malocclusion. 2. The more early treatment was done, the more duration of treatment was needed according to beginning age of treatment and Hellman's dental ages. 3. Treatment of tooth extraction case was needed for 78 days more than that of non-extraction case. 4. The duration of treatment with unilateral extraction of premolars was the shortest (598 days) and that with single arch extraction of premolars was the longest (685 days) according to types of tooth extraction. 5. The duration of treatment by removable appliance was the shortest (237 days) and the combination of removable appliance, headgear and full banded appliance was the longest (1425 days) according to types of orthodontic appliance. 6. The duration of treatment was 18 months in typical orthodontic treatment with 4 extraction of premolar and full banded appliance.

• The korean journal of orthodontics
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• v.43 no.6
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• pp.302-310
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• 2013

Orthodontic closure of old, edentulous spaces in the mandibular posterior region is a major challenge. In this report, we describe a method of orthodontic closure of edentulous spaces in the mandibular posterior region accelerated by piezoelectric decortication and alveolar ridge expansion. Combined piezosurgical and orthodontic treatments were used to close 14- and 15-mm-wide spaces in the mandibular left and right posterior areas, respectively, of a female patient, aged 18 years and 9 months, diagnosed with skeletal Class III malocclusion, hypodontia, and polydiastemas. After the piezoelectric decortication, segmental and full-arch mechanics were applied in the orthodontic phase. Despite some extent of root resorption and anchorage loss, the edentulous spaces were closed, and adequate function and esthetics were regained without further restorative treatment. Alveolar ridge expansion-assisted orthodontic space closure seems to be an effective and relatively less-invasive treatment alternative for edentulous spaces in the mandibular posterior region.

• The Journal of the Korean dental association
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• v.22 no.12 s.187
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• pp.1067-1073
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• 1984

In the treatment of functional orthodontic problems, timing is not an issue. All orthodontists start as soon as the condition is recognized. However, there is an active dialogue concerning treatment timing for structure problems. The major points in contention center around the operator's ability is to control the growth of the facial bones and to maintain post-treatment tooth position through the maturation period (especially when this position was gained by techniques involving arch expansion or distal driving of posterior segments). Factors taken into account to determine the best time of orthodontic treatment include diagnosis, interception, growth rate, patient cooperation, eruptive state and treatment period. With those exceptions of all functional problems, mild dental discrepancies and skeletal deficiencies with a predictably excellent growth potential (early treatment), the period immediately following the eruption of the permanent second molars is the period during which most orthodontic treatment should be initiated. At this time the full volume of tooth substances is present, the individual growth pattern in well established, there are sufficient teeth to receive nearly any type of appliances and the patient can easily tolerate the wearing of appliances.

• The Journal of the Korean dental association
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• v.23 no.7 s.194
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• pp.625-630
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• 1985

11 years 7 months old female had a reverse object of anterior teeth and class III molar relationship. Maxillary right and left canines were erupted labially and lower left lateral incisor was congenitally missed. She was treated by rapid palatal expansion and full band technique with extraction of maxillary and mandibular second molars. The following results were obtained. 1. Maxilary arch was expanded. 2. Anterior cross-bite and crowding was corrected. 3. Molar relationship was corrected. 4. Profile was somewhat improved.

• Journal of Ocean Engineering and Technology
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• v.19 no.2 s.63
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• pp.90-93
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• 2005

An improved approximate formula is presented for Series 60 forms, modifying the approximate formula, developed by the Author in 1983. The weather formula is based on interpretations of detailed calculations of speed loss, due to wind(van Berlekom), motions(Maruo), and wave reflection resistance(Kwon). Comparison is made between the result of the approximate formula and the one of detailed calculation. The result of the formula is also compared with some published full-scale data for speed loss.

• The korean journal of orthodontics
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• v.19 no.3
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• pp.147-160
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• 1989

Long face patients are characterized by excessive anterior facial height, lip incompetence at rest, anterior open bite, and gummy smile. A major problem is an inferior rotation of the posterior maxilla and upper molars. Long face patients have been the most difficult for orthodontist to treat successfully. In growing patients, the methods for impeding excessive vertical growth have been used high pull head gear, functional appliance, and combined type of two. One significant improvement comes from using a full arch splint to deliver force to the maxilla more vertically. In adult patients, orthodontic camouflage treatment is biomechanically difficult and doesn't work when the problem is primarilly vertical. Surgical maxillary impaction provides a means for successfully treating most of problems. Also, superior reposition of the chin via a mandibular inferior border osteotomy is effective in decrease of lower anterior facial height and correction of the poor chin-lip balance. Post-surgical stability and the physiologic response are good. The coordinated orthodontic and surgical treatment is necessary for solution the difficult skeletal deformity.

• The Journal of Advanced Prosthodontics
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• v.2 no.1
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• pp.1-3
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• 2010

BACKGROUND. Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION. This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION. This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.

• The Journal of Advanced Prosthodontics
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• v.5 no.2
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• pp.209-217
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• 2013

This clinical report presents the reconstruction of a maxillary arch with a cement retained implant supported fixed prosthesis using a monolithic zirconia generated by CAD/CAM system on eight osseointegrated implants. The prosthesis was copy milled from an interim prosthesis minimizing occlusal adjustments on the definitive prosthesis at the time of delivery. Monolithic zirconia provides high esthetics and reduces the number of metal alloys used in the oral cavity.

• The Journal of the Korean dental association
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• v.16 no.2 s.105
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• pp.147-150
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• 1978

The author conducted an experiment on the relativity between the mandibular buccal and lingual cusp inclines by means of measuring full arch plaster cast teeth of the fifty student subjects of the College of Dentistry, Seoul National University. The results were as follows: 1. The statistical relativity between the mandibular buccal and lingual cusp inclines in individual tooth was hardly recognized. 2. In the cusp incline data of the whole posterior teeth, the rough basis for the harmonizing with the other occlusion factors was recognizable. 3. The cusp inclination itself was incomplete in mechanical balance, therefore, it might be said that there were a lot of possibilities that the cusp incline may act as a potential etiological factor to give rise to occlusal diseases.

• Computers and Concrete
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• v.11 no.5
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• pp.365-382
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• 2013

Although shear reinforcement in beams typically consists of steel bars bent in the form of stirrups or hoops, the addition of deformed steel fibres to the concrete has been shown to enhance shear resistance and ductility in reinforced concrete beams. This paper presents a model that can be used to predict the shear strength of fibrous concrete rectangular members without stirrups. The model is an extension of the plasticity-based crack sliding model originally developed for plain concrete beams. The crack sliding model has been improved in order to take into account several aspects: the arch effect for deep beams, the post-cracking tensile strength of steel fibre reinforced concrete and its ability to control sliding along shear cracks, and the mitigation of the shear size effect due to presence of fibres. The results obtained by the model have been validated by a large set of experimental tests taken from literature, compared with several models proposed in literature, and numerical analyses are carried out showing the influence of fibres on the beam failure mode.