• The Journal of Korean Academy of Prosthodontics
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• v.61 no.4
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• pp.356-366
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• 2023

Support, retention, and stability of dentures are key factors in the use of complete dentures in edentulous patients. With the development of digital dentistry, attempts are being made to replace traditional treatment methods. Also, struggle to reduce the number of patient visits and to manufacture high-quality digitally fabricated dentures are ongoing. In this case, a digital denture was restored using a tray capable of obtaining centric relation through gothic arch tracing and a facial scan. By replacing the traditional complete denture restoration method, the number of patient visits was reduced and esthetic results with satisfactory denture support, retention, and stability were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.374-381
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• 2022

This case report introduces a 74-year-old male patient who visited retention deficiency of the mandibular implant overdenture, which was fabricated 20 years ago. When the existing dentures were used, the vertical dimension was reduced, the maxillary complete denture lacked lip support and retention, and the mandibular overdenture lacked clip retention due to damage to the bar attachment. After removing the damaged bar attachment, it was replaced with a ball attachment, and impressions were taken using the DENTCA^TM Tray and then the vertical dimension was measured. The gothic arch tracing was performed to record the centric relation. Obtained impressions were scanned and the shape of final dentures was designed using software and try-in dentures were fabricated using 3D printer. After evaluating the occlusal plane, occlusal relationship, facial shape, and pronunciation using the try-in dentures, the bite registration was recorded, and the final denture was manufactured based on this. The inner surface of the denture was adjusted and bilateral balanced occlusion was formed, and the housing was connected to the mandibular denture by a direct method. This case reports have shown satisfactory resultin recovering improved retention and esthetic outcome by increasing the vertical dimension and the lip support using CAD-CAM technique and the ball attachment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.145-151
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• 2015

The purpose of this study was to evaluate foodservice hygiene in middle school students by analyzing the importance and performance of school foodservice by meal service area in Busan. Questionnaires were administered to 826 students in 10 middle schools (five schools for classroom service, five schools for dining room service). The average importance and performance scores were 4.11/5.00 and 3.38/5.00 for classroom service and 4.34/5.00 and 3.89/5.00 for dining room service. Dining room service had significantly (P<0.001) higher average scores importance and performance of food hygiene, environment hygiene, equipment hygiene, and employee hygiene than those of classroom service. The gap average score of dining room service was significantly (P<0.001) lower than those of classroom service. In the importance-performance analysis, 'cleanliness of tray' showed high importance and low performance for classroom service and dining room service. Areas of low importance and low performance were 'tray drying', 'cleanliness of employee' clothes', 'wearing sanitary gown, cap', 'wearing sanitary mask', and 'wearing sanitary gloves' for the classroom service, whereas 'tray drying', 'comfortable atmosphere in diningroom', 'well ventilated', 'no odor of the food in classroom', and 'cleanliness around rubbish bins' were relevant for dining room service. These findings suggest that employee hygiene management should be intensively managed for classroom service, and equipment hygiene management must be improved for classroom service and dining room service, especially cleanliness of tray. Meal service places should be changed to the dining room with support the government and private sector.

• Journal of the Ergonomics Society of Korea
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• v.34 no.2
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• pp.167-177
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• 2015

Objective: The objective of this research is to develop evaluation checklist for personal office furniture and apparatus to shape comfortable and efficient worksite for workers' welfare improvement, productivity enhancement and labor force preservation, and to identify office work environment by applying the checklist. Background: Because most office workers work using computers in a sitting posture, the ratio of office workers among total musculoskeletal disorders patients is forecast to increase. In this regard, an effort to prevent and manage such musculoskeletal disorders is required. Method: This research developed evaluation checklist for personal office furniture and apparatus by examining 25 domestic and international ergonomic literature and anthropometric data. This research carried out a fact-finding survey targeting the A Office and B Office of one public agency using the checklist. Results: Although, the checklist items on desks, chairs, computers and other goods conformed to the checklist standards, the following items did not conformed: desk height adjustment, seat board depth adjustment, lumbar support depth, foot rest, wrist rest, mouse tray, headset, speaker phone and Bluetooth. Conclusion: The evaluation checklist for personal office furniture and apparatus and fact-finding survey results are considered to be used as basic data for office work environment and workers' welfare improvement. Application: The information drawn from this research can be helpful to manufacturers' design and manufacture of ergonomic furniture and apparatus.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.346-351
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• 2014

Suction dentures enhance retention and support by forming negative pressure temporarily at the internal surface of denture base at times of swallowing and chewing because the areas surrounding the denture flanges are sealed by mobile mucosa. In this case, an 81-year-old male visited for new dentures. Considering the high expectations for retention and masticatory efficiency of dentures, fabricating complete dentures with suction dentures was planned. Preliminary impression was taken without applying pressure on retromolar pad area and diagnostic cast was fabricated. Afterwards, individual tray was made and final impression was taken, at the same time, gothic arch tracing was done to acquire centric relation and vertical dimension. Then, anatomic teeth were placed on maxilla and non-anatomic teeth were placed on mandible forming lingualized occlusion. Consequently, restoring a complete edentulous patient with complete dentures using mandibular suction denture resulted in recovering satisfying retention and function.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.3
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• pp.158-167
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• 2023

As digital technology has advanced in the field of dentistry, the use of computer-aided design/computer-aided manufacturing (CAD/CAM) has brought changes to the stages of dental treatment. The use of CAD/CAM technology in dental restoration offers clinical efficiency and convenience by reducing production time and appointment intervals, while also simplifying the fabrication process to reduce errors. In this case, digital replication and printing of temporary teeth were used to aid a patient with complex medical histories and physical disabilities. The final impression obtained with silicone impression material included information on the vertical dimension, centric relation, and the angle and length of the anterior teeth, which shortened the production time and appointment intervals and increased patient satisfaction. The final restoration was fabricated using milling and monolithic disc techniques, demonstrating appropriate stability, retention, and support, resulting in functional and aesthetic satisfaction.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.529-537
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• 2021

Membrane-type hull and cargo holds have been designed and built for large ship. However, there is a growing interest in applying the same technology to small and medium-sized Liquefied natural gas(LNG) carriers to meet the recent increase in demand for LNG as an ecofriendly fuel and for expanding LNG bunkering infrastructure. The purpose of this study is to apply the IMO Type-B tank to small and medium-sized LNG carriers and verify the safety and suitability of the design. Fatigue crack propagation analysis was performed to install a partial second drip tray installed at the lower part of the LNG cargo tank by calculating the amount of leaked gas in the support structure supporting the cargo tank. First, a program for fatigue crack propagation analysis was developed, in which Paris' law and British Standard 7910 (BS 79110) were applied based on the International Code for the Construction of Equipment and Ships Carrying Liquefied Gases in Bulk, an international standard for LNG carriers. In addition, a surface crack propagation analysis was performed. Next, a methodology for assuming the initial through-crack size was developed to determine the size of the partial second barrier. The analysis was performed for 15 days, which is a possible return time after cracks are detected. Finally, the safety and suitability of the IMO Type-B for LNG cargo tanks required by international regulations were verified. For the accurate analysis of fatigue crack propagation, it is necessary to develop and verify the analysis procedure based on direct analysis and international regulations.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.202-210
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• 2022

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.