• Journal of Korean Academy of Dental Administration
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• v.8 no.1
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• pp.30-36
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• 2020

This study is conducted on 1,725 elderly people over 65 years of age using 2018 data obtained from the 7th National Health and Nutrition Survey (KNHANES) data. In this study, an analysis is performed considering the general characteristics of the elderly and their oral health status (authoring discomfort, speech problems, etc.) to confirm the relationship between the elderly's unmet dental experience and depressive experience. The results of this study showed that depressive experiences by the elderly resulted in unmet dental medical experiences, and it was also found that the income level and the complaint of chewing discomfort had an effect. Based on these results, it is believed that oral health policies should be developed to improve the unmet dental medical experience by considering the socio-economic level of the elderly and depressive experiences. This policy development is expected to lead not only to the improvement of oral health for the elderly, but also to improve the quality of life for the elderly through health promotion.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.505-513
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• 2022

Minor orthodontic treatment using a thin wire with high elasticity can shorten the treatment period and reduce the load on the anchorage by the application of light force. Since it can be applied immediately without a dental laboratory procedure and does not require the patient's cooperation, it can be clinically useful. The cases reported here have led to positive results in short periods of treatment, using only a segmented straight 0.012 inch NiTi wire and flowable resin to address various locations within the oral cavity, such as the anterior teeth, premolars, and molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.98-108
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• 2018

This study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of the patients with skeletal class II division 1 or division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group (79 for pre-peak, 40 for peak, 40 for post-peak). Total 159 lateral cephalograms (70 for skeletal class I, 51 for skeletal class II, division 1, and 38 for skeletal class II, division 2) were selected. The growth of anteroposterior dimension of the pharyngeal airway were statistically significant among growth periods. The dimension for the nasopharyngeal and oropharyngeal airway space was the smallest in the division 1 skeletal class II group followed by class II division 2 and skeletal class I.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.38-46
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• 2017

School nurses can play an important role in improving the prognosis of traumatized teeth of school children when they are informed about the immediate and proper dental first aid steps. The purpose of this study were to assess the awareness of school nurses concerning the management of traumatized teeth and to determine if a lecture on dental trauma management could improve school nurses'knowledge on this topic. School nurses in Gwangju and Jeonnam province completed a questionnaire before and after the lecture on the first-aid knowledge with particular focus on the following three categories. Questionnaires are composed of questions asking general information and about knowledge and proper attitude in case of the specific situation on dental trauma. According to previous studies, school nurses' knowledge tended to be higher compared with the teachers. Improvement of knowledge in school nurse was observed in emergency actions, in visiting time, replantation, carriage method, vaccine prescription related with luxation, and in possibility of fragment reattachment related with subluxation and fracture. In conclusion, it is recommended that periodical education are needed for improvement of school nurses'knowledge on proper management of dental trauma emergency.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.299-306
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• 2018

The aim of this study was to evaluate the effect of etching time and bonding agents on bond strength of sealant applied to the occlusal surface of primary molars. Forty non-carious exfoliated human primary molars were included in the study. The teeth were randomly divided into 4 groups for measurement. For group I, no acid etching treatment was used. For group II, III, and IV, acid etching gels were applied on the occlusal surface for 15, 30, and 60 seconds, respectively. Each group was divided into 2 subgroups; one group was treated with bonding agents on the enamel while the other was not. Microtensile bond strength was evaluated using a universal testing machine. There were no statistically significant differences in bond strength with varying duration of etching among groups. The results revealed that the use of bonding agents prior to application of fissure sealant increased the bond strength(p < 0.05). It could be concluded that etching time greater than 15 seconds does not significantly enhance the bond strength, but the use of bonding agents as an intermediate layer between the primary molar and fissure sealant would be beneficial in increasing the bond strength.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.2
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• pp.257-264
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• 2018

Osteopetrosis is characterized by impaired osteoclast function and increased bone density. Infantile osteopetrosis is a severe form of the disease and has characteristics such as diffusely sclerotic skeleton, pancytopenia, cranial nerve entrapment, infection susceptibility, and abnormal craniofacial appearance. Patients with infantile osteopetrosis often experience developmental delay, and may have a short life span. A 14-month-old girl with osteopetrosis presented to the department of pediatric dentistry. Incipient caries on deciduous incisors were observed. The patient revisited 4 years of age. Besides medical problems, oral complications such as growth retardation, narrow upper arch, crowding, dental caries, and abnormal tooth development were observed. After consultation with her pediatrician, dental treatments were performed on the deciduous molars under sedation after a prophylactic antibiotic injection. At a periodic follow-up, multiple deciduous teeth were treated and extracted, and oralrehabilitation with a removable partial denture was initiated. Patient with osteopetrosis are highly susceptible to infection because of their compromised immune system and problems associated with wound healing that lead to osteomyelitis or sepsis development. Active participation in dental care for sugar intake management and proper oral hygiene are obligatory.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.5
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• pp.401-414
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• 2018

Planing hull type ships are often equipped with interceptor or trim tab to improve the excessive trim angle which leads to poor resistance and sea keeping performances. The purpose of this study is to design a controller to control the attitude of the ship by controllable stern interceptor and validate the effectiveness of the attitude control by the towing tank test. Embedded controller, servo motor and controllable stern interceptor system were equipped with planing hull type model ship. Prior to designing the control algorithm, a model test was performed to identify the system dynamic model of the planing hull type ship including the stern interceptor. The matrix components of model were optimized by Genetic Algorithm. Using the identified model, PID controller which is a classical controller and sliding mode controller which is a nonlinear robust controller were designed. Gain tuning of the controllers and running simulation was conducted before the towing tank test. Inserting the designed control algorithm into the embedded controller of the model ship, the effectiveness of the active control of the stern interceptor was validated by towing tank test. In still water test with small disturbance, the sliding mode controller showed better performance of canceling the disturbance and the steady-state control performance than the PID controller.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.455-463
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• 2018

The purpose of this study was to evaluate the effect of the intracanal medicaments on the push-out bond strength of the calcium silicate-based materials. Forty extracted single-root human mandibular premolars were sectioned below cementoenamel junction. Standardized root canal dimension was obtained with a parallel post drill. The specimens were randomly divided into a control group (no medicament), and experimental groups received medicaments with either CH (calcium hydroxide), DAP (double antibiotic paste; a mixture of ciprofloxacin and metronidazole), or TAP (triple antibiotic paste; a mixture of minocycline, ciprofloxacin and metronidazole). Following removal of medicaments with irrigation, roots were cut into sections with 1-mm-thickness. Thereafter, calcium silicate-based materials are applied to the specimens : (i) ProRoot MTA$^{(R)}$ and (ii) Biodentine$^{(R)}$. A push-out bond strength was measured and each specimen was examined to evaluate failure mode. Intracanal medication using CH significantly increased the bond strength to the root dentin. But there are no significant differences on the bond strength of ProRoot MTA$^{(R)}$ or Biodentine$^{(R)}$ among TAP, DAP and control groups. The dislodgement resistance of Biodentine$^{(R)}$ from root dentin was significantly higher than that of ProRoot MTA$^{(R)}$ regardless of the type of intracanal medicaments.

• KSBB Journal
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• v.14 no.6
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• pp.702-706
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• 1999

The genetic responses of aquaculturable seaweed Prophyra yezoensis tissue by acid shock have been compared using differential display technique. The tissue has been challenged in seawater containing 0.05% hydrogen chloride(pH 3.0) for 5 min, then rehabilitated in normal seawater for 10 min, 30 min, 60 min and 4 hrs, respectively. Total RNA was extracted by LiCl-guanidinium method. The cDNA was synthesized by reverse transcription with random hexamers and amplified by PCR with arbitrary primers. The genetic fragment disappeared by acid shock was selectively isolated from agarose gel and sequenced with a DNA auto sequencer. One of the acid-labile gene(605 bp) was identified as a dethiobiotin synthetase gene according to sequence alignment analysis by the NCBI BLAST search program.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.293-302
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• 2020

The purpose of this study was to evaluate the applicability of virtual reality simulation after experience of dental caries diagnosis for dental students before exposing to clinical pediatric practice. A pediatric patient model of a five-year-old child with primary dentition was developed and a caries model that is amenable to VR(virtual reality) diagnosis was organized and set-up. The dental student's were allowed to use the simulated model for fifteen minutes and their experiences were evaluated using a self-reported questionnaire to evaluate presence and usability of this application. Overall, virtual presence and appearance area of the simulation were highly scored. The result indicates that the VR model has no significant difference from the actual clinical caries regardless of grade of students, gender and VR experience. If the prototype is continuously advanced, its applicability in dental education will increase.