• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.5
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• pp.153-158
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• 2018

Complicated crown-root fractures are considered rare occurrences in young permanent dentition; however, they often present complicated and unpredictable treatment options. The most common treatment option for crown-root fractured teeth is reattachment of fractured segment, but if it is thought impossible to maintain, it should be extracted. However, when unfavorable crown-root fracture occurs in the adolescents, extraction of fractured teeth is expected to be poor due to excessive resorption of alveolar and prosthetic replacement cannot be performed immediately, various treatment options should be considered. This report suggests root submergence in the complex crown-root fracture in growing patients is performed and the functional and aesthetic results including preservation of the alveolar bone are obtained.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.232-237
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• 1995

The absorption spectra of holmium nitrate and erbium nitrate and the difference absorption spectra of their complexes with crown ethers were measured in acetonitrile. The crown ethers used in this study are 12-crown-4 and 15-crown-5. The oscillator strengths for the 4f→4f multiplet-to-multiplet transitions are empirically determined from the absorption spectra in combination with the difference spectra. The intensity parameters Ωλ (λ=2, 4, 6) for the systems are also evaluated by applying the Judd-Ofelt theorem to the observed oscillator strengths. The values of the intensity parameters are compared and discussed to investigate the sensitivity of the intensity parameters to the ligand environment.

• The Korean Journal of Archival Studies
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• no.36
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• pp.35-67
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• 2013

As the office of crown properties expanded to financial structure having jurisdiction over various nation's purse in the Great Han Empire, its official document form has been changed. Unlike the early days, they had used official paper stamped with the words 'the Office of Crown Properties' eliminating 'Department of the Royal Household'. Also, the title on stamp of government position changed to 'Recipient of the Official of Crown Properties'. As the office of crown properties expanded as a great financial structure, it has grown in stature as an independent structure, and it was reflected in official document form. Such change was shown in document distribution system. The recipient of report from each district was the First Lord of Department of the Royal Household until 1897; however, the recipients of reports were mostly the office of Crown Properties from 1899. The Office of Crown Properties could not issue an official order before Aug 1899, since then the Office of Crown Properties had issued official orders to each district. However, the Office of Crown Properties could not handle the document in an equal position to the central organization yet. However, from Sep. 1900, the Office of Crown Properties handle the document with district organizations in equal position to the central organization, and a records office had been established in the Office of Crown Properties. Also, the Office of Crown Properties had handled official documents as an independent organization getting out of belonging organization to the department of Royal Household. Since the records office was established in Sep. 1900, the Office of Crown Properties had written receipt book autonomously. Comparing the receipt books in 1901 to the receipt books in 1905 and 1906, receipt numbers had been appeared from the book in 1905 and the organization in charge of the documents was recorded on some documents. Since no receipt book was found in 1902~1904, it is unknown when receipt number had been started indicating on the book. Seeing that the receipt number on the book of 1905 matched with contents on the receipt stamp, the receipt number has started indicating from around July, 1902; the period the receipt stamp has been started to use. Unlike the receipt stamp, the department in charge was indicated on the receipt book. It is because that the Office of Crown Properties changed writing system. Instead of classifying divisions, the Office of Crown Properties recorded in a book by order to receive, provided serial number, and wrote the department on the bottom of receipt book to classify by department in charge. Since establishment of the records office in Sep. 1900, the Office of Crown Properties had confirmed the receipt of document by stamping 'receipt of the Office of Crown Properties' and made receipt books as the office had started handled documents independently. Also, the Office of Crown Properties changed its system integrating division and recording in one book from the intial system classifying the book by division then receipt number and department in charge were indicated on the book. Also, receipt system has stabilized by stamping the receipt date and number on the received document.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.64-75
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• 2019

The purpose of this study was to obtain instructions for size selection of prefabricated crown and tooth reduction by 3-dimensional analysis of the size and shape of the maxillary primary central and lateral incisors and prefabricated crowns (celluloid strip, resin veneered stainless steel, and zirconia crowns). The maxillary primary central and lateral incisors of 300 Korean children was scanned with three types of prefabricated crown to create standard three-dimensional tooth models and prefabricated crowns. The shapes of the prefabricated crowns and natural teeth were compared according to four parameters (mesio-distal width, height, labio-palatal width, and labial surface curvature coefficient) and calculated the amount of tooth reduction required for each prefabricated crown. The size 2 resin veneered stainless steel crown, size 1 zirconia crown, and size 2 celluloid strip crown were most similar in shape to the primary central incisor. The size 3 rein veneered stainless steel crown, size 2 zirconia crown, and size 3 celluloid strip crown were most similar to the primary lateral incisor. The amount of tooth reduction was similar in both maxillary primary central and lateral incisors. The incisal reduction was greatest for the zirconia crown. At the proximal surface, the zirconia and celluloid strip crowns required a similar amount of tooth reduction, but more than the resin veneered stainless steel crown. The labial surface reduction was greatest for the zirconia crown. The degree of lingual surface reduction was not significant among the three prefabricated crowns. Among the assessment parameters, mesio-distal crown width was the most important for choosing a prefabricated crown closest to the actual size of the natural crown.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.1969-1974
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• 2005

Composite systems of $Eu(phen)_2Cl_3{(H_2O)}_2$, Eu(DN-bpy)$(phen)Cl_3{(H_2O)}_2$ and Eu(DB-bpy)$(phen)Cl_3{(H_2O)}_2$ (DNbpy: $4,4^\prime$-Dinonyl-$2,2^\prime$-dipyridyl; DB-bpy: $4,4^\prime$-Di-tert-butyl-$2,2^\prime$-dipyridyl) with crown ethers of Benzo-15-crown-5 (B15C5), Benzo-18-crown-6 (B18C6), 18-crown-6 (18C6), Dibenzo-18-crown-6 (DB18C6) and Dibenzo-24-crown-8 (DB24C8) were fabricated successfully and characterized by using photoluminescent spectroscopy and luminescent lifetime measurements. All composites formed show high luminescence mainly in red region. It was found that the heterocyclic ligands such as phen, DN-bpy and DB-bpy as well as the crown ethers have great influences on the photoluminescent properties of $Eu^{3+}$ ion. The environment around $Eu^{3+}$ ion in the composite systems changes greatly,presumably the variation of the first coordination sphere. The $Eu^{3+}$ ion occupies higher symmetrical environment and in more than one kind of symmetrical site in the composite systems studied in this work.

• Journal of the Korean Society of Costume
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• v.59 no.10
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• pp.68-84
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• 2009

A state wedding ceremony of kings and crown princes in the Chosun Dynasty was systemically formalized in a book Five National Ceremonies (1474) as one of the five major formal events of the royal auspicious ceremonies(Ga-rae). For a state wedding, Ga-rae Protocol was made by a devision for Ga-rae temporarily established for the occasion. A total number of auspicious ceremony protocols of kings and crown princes amounts to 20 in the span of 279 years. Among the proposals, the wedding of Soon-jong in the Imo Year of 1882 is described most thoroughly. Nap-bin-ui(reception of bride) comprises six rituals which are nap-chae, nap-jing, go-gyi, chaek-bin, chin-young, and dong-ryae. A grand formal costume of the crown prince is granted based on the 'Seven Parts Formal Costume' of the first year of the king Moon-jong in 1450 together with an official costume for crown prince(Gon-myeon-chil-jang) arranged in the third year of the king Young-rak. In the royal palace of the Chosun Dynasty, the granted formal costume of the crown prince is officially recorded as a code and presented in a Gwon-ji-il section of the Formalities of the Five National Ceremonies. The formal costume and its accessory set for the crown prince recorded as a code are described in Sangbang Jeong-ryae as the formal costume of the crown prince section published by the king's request at the high senate commission in the 28th year of the king Young-jo in 1752. The aim of the study is to investigate the formal costume of the crown prince as an auspicious ceremonial costume worn at the wedding in the year of Imo.

• Polymer(Korea)
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• v.30 no.5
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• pp.426-431
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• 2006

Novel azacrown ether containing blue -light emitting anthracene fluorophore, 9,10-bis [p-(1-aza-18-crown-6)methylphenyl] anthracene (3) and N,N-bis [9-(p-methylphenyl) anthracenyl-methyl] -1,6-diaza-18-crown-6 (4) were prepared by reacting anthracene derivatives 1 and 2 with mono- and diaza-18-crown-6, respectively Also, crown ether containing fluorophore copolymer (5) were prepared by reacting 1,6-diaza-18-crown-6 with 1. Their fluorescence emission spectral studies were investigated by binding group I, group II and various metal cations. The fluorophores showed an absorption at ${\lambda}_{max}$= 372 nm and an emission at ${\lambda}_{max}$= 430 nm. pH Dependency of fluorescence emission intensity were examined to determine the optimum pH for the fluorophores.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.479-508
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• 1994

This study was designed to investigate the reciprocal movement which was derived form application of active torque in ideal archwire by computer-aided three-dimensional finite element analysis of maxillary teeth and surrounding periodontal ligament composed of 2617 elements and 3725 nodes. Ideal archwire model was also made using the beam elements and the contact between the wire and the bracket slot was made using the gap element. In this study non-linear elastic behaviors of contact between the wire and the bracket slot were considered on. We put the active torque between the lateral and cenral incisor and between the second premolar and the first molar with/without cinch-back. The results were expressed by quantitative and visible ways. The findings of this study were as follows: 1. Reciprocal actions to active torque were complex system consisting of a combination of counter-torque, bucco-lingual linear displacement and tipping, rotation of the teeth, occluso-gingival linear displacement. 2. When active anterior crown labial torque was applied, crown labial tippings of the lateral were the greatest, and those of the central incisor was the next, Crown lingual tippings of the canine and the first premolar, mesial rotations and extrusion of the lateral and distal rotations and intrusion of the canine occurred. When anterior torque with the cinch-back was applied, amount of crown labial tippings of the lateral and central incisor were reduced. Amount of crown lingual tipping of the canine and the first premolar were increased. Mesial tippings and mesial rotations of the second molar occurred. 3. When active posterior crown lingual torque was applied, crown lingual tippings of the first moalr were the greatest, and crown labial tippings of the second premolar and the first premolar were the next, the crown lingual tipping of the second molar were a little. Mesial rotations of the second premolar occurred but those of the first premolar didn't occurred.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.415-424
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• 2013

Purpose: This study is to present a standard value for clinical crown angulation and inclination required in laboratory process and see if the value can be used for actual laboratory process. Methods: In order to find out a standard value for clinical crown angulation and inclination, this study made a study model of normal occlusion of 21 females in twenties. The clinical crown angulation and inclination of both six-maxillary and six-mandibular anterior teeth are measured by Set-up Model Checker. From the measured value above, the mean and standard deviation of the twelve teeth are obtained, and then the mean of the teeth between right and left side is calculated. Results: Each clinical crown angulation of maxillary central incisor, lateral incisor, and canine is like this; $1.0^{\circ}{\pm}1.3^{\circ}$, $3.0^{\circ}{\pm}1.3^{\circ}$, and $5.0^{\circ}{\pm}1.4^{\circ}$. In case of mandibular, each degree is like this; $0.6^{\circ}{\pm}1.1^{\circ}$, $1.5^{\circ}{\pm}1.1^{\circ}$, and $4.1^{\circ}{\pm}1.1^{\circ}$. Each clinical crown inclination of maxillary central incisor, lateral incisor, and canine is like this; $6.1^{\circ}{\pm}1.8^{\circ}$, $4.5^{\circ}{\pm}1.9^{\circ}$, and $-6.2^{\circ}{\pm}1.4^{\circ}$. In case of mandibular, each degree is like this; $0.3^{\circ}{\pm}1.5^{\circ}$, $0.3^{\circ}{\pm}1.8^{\circ}$, and $-7.5^{\circ}{\pm}1.8^{\circ}$. Conclusion: As the result, the mean value for clinical crown angulation and inclination can be referred to actual laboratory process. However, the mean value is different from those of the precedent study and an unsatisfied one for adopting the standard value.

• Bulletin of the Korean Chemical Society
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• v.11 no.6
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• pp.521-527
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• 1990

The binding characteristics and analytical applications of anilinium ion complexes with 18-crown-6 were studied by polarography and NMR. First, the electrochemical reduction of the 10 species of mono and dimethylsubstituted anilinium ion complexes with 18-crown-6 as host in methanol are examined. The addition of 18-crown-6 to anilinium guest solution the polarographic waves remain well defined but shifted toward more negative potentials, indicating the complex formation. The values of formation constants, log Κ for 10 species of methylsubstituted anilinium ion complexes with 18-crown-6 varies from 2.7 to 4.8 in methanol at $25^{\circ}C$. The stability order of complexes for 18-crown-6 is anilinilum > 4-methyl > 3,4-dimethyl > 3-methyl > 3,5-dimethyl > 2,4-dimethyl > 2,5-dimethyl > 2,3-dimethyl > 2-methyl > 2,6-dimethylanilinium ion. The steric hindrance shows significant effect. Second, Proton NMR was used to elucidate their interaction characteristics. From the results of so called NMR titration techniques, the behaviors of binding sites on complexation, and the stoichiometry and stability order of complex were obtained. And the later results show the satisfactory agreement with the quantitative values obtained by polarography. Finally, the individual determinations of anilinium ion mixtures were also accomplished by addition of 18-crown-6. In some mixtures of methyl or dimethylanilinium ions the reduction peaks of differential pulse method appeared into one unresolved wave attributed to the small difference of half-wave potential, ${\Delta}E_{1/2}$. In the presence of 18-crown-6, the polarographic waves were resolved into individual maxima because of the shift toward more negative direction by the difference of selectivity of anilinium ions with 18-crown-6. It may be concluded that quantitative analysis of methylanilinium ion mixture make possible because the half-wave potential shift by the selectivity difference due to the steric hindrance between methyl group and 18-crown-6 on complexation.