• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.51-59
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• 2004

Background: The objective of this study is to evaluate the relationship between chewing ability and health status in order to provide basic information for the development of program which may lead to an improvement of a the elderly health status in urban areas. Materials and methods: The subjects of this study were 128 elderly urban female over the age of 65 who reside at house. The data were collected from May 21 to August 20, 2001, through questionnaires about nutrient intake status, direct measurement of anthropometrics, and oral examinations. Results: In terms of remaining teeth, there was significant negative relationship between age and number of remained teeth. The average number of remained teeth our subjects was $13.1{\pm}10.6$. About sixty five percent of the subjects were denture users (partial or full dentures) and there was positive relationship between age and the percentage of denture user. There was a significant negative correlation between age and chewing ability. The group that was able to chew had more remained teeth than the other group. Conclusion: This study suggests that there is strong positive relationship between chewing ability (remaining teeth) and elderly health status in urban areas, and the importance of preserving original teeth to improve the elderly health status in the public health program.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.3
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• pp.188-198
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• 2018

Purpose: Recently, according to the development of digital technology, computer aided design/computer aided manufacture (CAD/CAM) system is widely used for fabrication of various dental prostheses in the field of dentistry. This study aims to survey the present state and awareness of CAD/CAM system on domestic dental field, and to supply the advice for the application of the new system. Materials and methods: In this questionnaire survey was conducted for a total of 298 dentists, dental hygienist and dental technicians of the whole country including the dental hospital of Seoul National University for two months from November to December, 2016 through mail. Results: The most important purpose to consider when purchasing a dental CAD/CAM milling machine were the performance of the milling machine (64.43%) and the use of milling machine was the highest with 49.33% of manufacturing for dental prosthesis and customized implant abutment. In addition, more than 60% of respondents answered positively about the purchase of new milling machine if the CAD/CAM milling machine was improved to satisfactory performance. Conclusion: This survey results show that the improved CAD/CAM milling machine would be play an important role in the dental industry in preparation for digitization and the 4th industrial revolution.

• Imaging Science in Dentistry
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• v.41 no.1
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• pp.35-38
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• 2011

Necrotizing sialometaplasia (NS) which mimics malignancy both clinically and histopathologically is an uncommon benign, self-limiting inflammatory disease of the mucus-secreting minor salivary glands. The lesion is believed to be the result of vascular ischemia that may be initiated by trauma. Till date, the diagnosis of NS remains a challenge. This report demonstrates a case of NS in a 73-year-old male patient who presented with an ulcerative lesion in his palate. He had a history of local trauma and was long-term user of salbutamol inhaler. An incisional biopsy was carried out and the diagnosis was established through history, clinical examination, histopathology using Hematoxylin and Eosin stain. The patient was given symptomatic treatment and the lesion healed in about 7 weeks.

• International journal of advanced smart convergence
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• v.7 no.4
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• pp.114-120
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• 2018

The purpose of this paper is to develop simulations that can be used for virtual education in dentistry. This development goal is to allow dental students to learn the necessary surgical techniques at the point of their choice, not going into the operating room, away from time, space, and physical limits. In this paper configuration, the optimization method is applied convergent, and when the operation of the VR contents is performed, the content data is extracted from the interaction analysis formed in the VR engine, and the data is processed by the content algorithm. It also computes events and dental operations generated within the 3D engine programming and generates corresponding events through data processing according to the input signal. The visualization information is output to the HMD using the rendering information. In addition, the operating room environment was constructed by studying lighting and material for actual operating room environment. We applied the ratio of actual space to virtual space and the ratio between character and actual person to create a spatial composition at a similar rate to actual space.

• Journal of Technologic Dentistry
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• v.44 no.3
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• pp.89-96
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• 2022

Purpose: The purpose of this study was to investigate the types of mouthguards athletes who play contact sports use as well as their perceived discomfort of wearing them in order to analyze the relationship with wearing frequency so as acquire basic data for the development of more user-friendly mouthguards. Methods: The participants, who completed a self-report questionnaire, included 70 contact sports athletes, including high school contact (rugby and boxing) sport department affiliated athletes located in the city of Daejeon. Results: Breathing (p<0.01), fitting (p<0.05), ease of wearing (p<0.01), occlusion (p<0.05), and fatigue in muscles (p<0.05) were positively correlated with wearing frequency. Furthermore, the recognition of the mouthguards was not significantly correlated with wearing frequency. Conclusion: To prevent oral and maxillofacial trauma, multi-directional studies are imperative to develop mouthguards, which are comfortable and cost-efficient.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.178-185
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• 2015

Purpose: The purpose of this study was to conduct a comparative assessment on the satisfaction level for the two interfaces of surgical guide system (SimPlant and R2GATE), the design and convenience of manufactured surgical guides and the importance of using the surgical guides thereof by means of survey. Materials and Methods: Hereupon, they simulated the implant surgical process by mounting the two manufactured systems of surgical guide on a dental mold, respectively. The study subjects were instructed to complete the questionnaire as to the satisfaction level upon completion of the simulated surgery. This study summarized the data of each question after collecting the completed questionnaires. Then, this study analyzed the summarized data by utilizing statistical program SPSS 20.0 (IBM). Results: R2GATE had a higher value of the satisfaction level on the design and convenience of manufactures surgical guides. R2GATE group ($7.33{\pm}1.26$) was found to have a higher value in terms of the overall satisfaction level compared to SimPlant group ($6.67{\pm}1.26$) (${\alpha}$ = 0.05). Conclusion: The user satisfaction level on the surgical guide manufactured for R2GATE system was to such an extent as it can be widely used in clinical environment. Moreover, the surgical guide manufactured as R2GATE system can guide both the length and direction of a drill simultaneously. As a result, it is highly recommended for those beginners who do not have a lot of experience in implant placement.

• Journal of Oral Medicine and Pain
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• v.41 no.3
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• pp.85-90
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• 2016

Purpose: The aim of this study was to develop an automated software to extract tooth and pulpal area from sectional cone-beam computed tomography (CBCT) images, which can guarantee more reproducible, objective and time-saving way to measure pulp/tooth volume ratio. Methods: The software program was developed using MATLAB (MathWorks). To determine the optimal threshold for the region of interest (ROI) extraction, user interface to adjust the threshold for extraction algorithm was added. Default threshold was determined after several trials to make the outline of extracted ROI fitting to the tooth and pulpal outlines. To test the effect of starting point location selected initially in the pulpal area on the final result, pulp/tooth volume ratio was calculated 5 times with different 5 starting points. Results: Navigation interface is composed of image loading, zoom-in, zoom-out, and move tool. ROI extraction process can be shown by check in the option box. Default threshold is adjusted for the extracted tooth area to cover whole tooth including dentin, cementum, and enamel. Of course, the result can be corrected, if necessary, by the examiner as well as by changing the threshold of density of hard tissue. Extracted tooth and pulp area are reconstructed three-dimensional (3D) and pulp/tooth volume ratio is calculated by voxel counting on reconstructed model. The difference between the pulp/tooth volume ratio results from the 5 different extraction starting points was not significant. Conclusions: In further studies based on a large-scale sample, the most proper threshold to present the most significant relationship between age and pulp/tooth volume ratio and the tooth correlated with age the most will be explored. If the software can be improved to use whole CBCT data set rather than just sectional images and to detect pulp canal in the original 3D images generated by CBCT software itself, it will be more promising in practical uses.

• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.308-314
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• 2013

Purpose: The purposes of this study were to assess the dentists' subjective satisfaction with the crestal approach sinus (CAS) kit, a device for maxillary sinus membrane elevation by the crestal approach using a special drilling system and hydraulic pressure, and to summarize the subjective satisfaction of dental implants placed after a sinus lift procedure with the CAS kit. Methods: Thirty dental clinicians who had experience with dental implant placement after a sinus lift procedure with the CAS kit from June 2010 to May 2012 were included in this study. The questionnaire for the evaluation of the dentists' subjective satisfaction with the CAS kit was sent to the respondents and returned. The questionnaire was composed of two main parts. The first part was related to the sinus membrane perforation rate. The second part was related to the dentists' subjective satisfaction with the CAS kit. Results: A total of 28 dentists answered the questionnaire. Among 924 implant cases, sinus membrane perforation occurred in 38 cases (4.1%). Among the 28 dentists, 26 dentists (92.9%) were satisfied or very satisfied with the CAS kit. In particular, 24 dentists (85.7%) reported that safety, cutting performance, and user-friendliness of the CAS drill were advantages of the CAS kit. However, 7 dentists (25%) did not routinely use the hydraulic lifter for sinus membrane elevation. Conclusions: From the survey, it was shown that the respondents were generally satisfied with the CAS kit and that the cutting performance and safety of the drill component were considered strengths of the CAS kit.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.2
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• pp.68-78
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• 2016

Recently, digital technology has become increasingly prevalent in the dental clinic. Using a milling machine for clinic, it is possible to produce provisional restoration inside the clinic. This can promote large clinical cases such as full mouth rehabilitation with the help of a tabletop scanner, which is capable of semi-adjustable articulator equipment, and a powerful dental CAD software with excellent user convenience. In this case report, a full-mouth rehabilitation was done with digital technology to a 55 year-old female patient, who has lost vertical dimension through the attrition, and has got inclined occlusal plane with unplanned and repeated dental reconstruction. Through the design and milling of the provisional restoration in the clinic and the duplication of these provisionals by double scanning technique, a good functional and esthetic result could be achieved.

• Journal of Technologic Dentistry
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• v.28 no.1
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• pp.67-81
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• 2006

This research has been attempt to examine closely factors that high cost and value to overall satisfaction state for dental implant prosthesis, re-utilization intention, inducement intention of the general hospital dental service user and provide basis data necessary to establish competitive general hospital dentistry management strategy. Collected data using own recording way questionnaire from April 17, 2004 to May 15, 2004 choosing 142 people that agree on this research and question of 361 people that dental implant prosthetic treatment finished from March 1, 1999 to March 1, 2004 for this. Major analyzation consequences are as follows : First, general satisfaction, re-utilization intention, inducement intention for implant prosthesis that highly correlation variables are kindness, explanation, medical treatment level and appreciation of the aesthetic. Second, correlation is high relatively between re-utilization intention, inducement intention in the 3 variables such as general satisfaction re-utilization intention, inducement intention. Third, the result of multiple regression analysis showed that most significant effective factors are satisfaction with explanation of dental implant prosthesis between the 3 dependant variables such as general satisfaction, re-utilization intention, inducement intention. In looking into these consequence, how to improve that raise satisfaction about dental implant prosthetic treatment and to establish patient focused care service system for dental implant prosthesis, it is consider that explain enough about implant prosthesis and raise quality of medical examination and treatment level, including satisfied with fabrication of good esthetic dental implant prosthesis.