• The Journal of Korean Academy of Prosthodontics
• /
• v.54 no.1
• /
• pp.35-40
• /
• 2016

The maxillary defects lead to anatomical and functional deformity of the maxillofacial region. As far as functions are concerned, such defects can produce difficulty in speech, mastication, and deglutition. Obturator prostheses play a very important role in functional recovery for post-maxillectomy patients. To achieve rigidity of the obturator, appropriate retention should be given, and the weight of the prosthesis be reduced. There are two types of hollow bulb obturator: open and closed. A closed type has many advantages. Nevertheless, some problems, including complexity of fabrication and water leakage into the bulb, have the closed hollow obturator not be widely used. The one-step polymerization technique described in this case overcomes the shortcomings by easily constructing a small hollow bulb with two thermoplastic resin sheets.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6427-6433
• /
• 2013

For trains to run safely and quickly, the train should always follow the preceding train at a proper spacing. For this purpose, a certain distance between the stations is set for each block section. For the safe operation of trains in one block section, only one train service for an automatic block system is needed. The existing block system is composed an ABS, which is a linked track circuit and line sideway system through the interlocking system. The interlocking system is being replaced with a domestic electronic interlocking system. On the other hand, the block system still uses the relay format of an analog system, and is independently installed of the line sideway systems. Therefore, the existing block system has many problems in terms of construction and maintenance. In addition, the existing domestic line is used for ABS and LEU , which is installed separately, despite the train being controlled by the information of the same signal at the same location. This is not efficient in terms of each product price and the maintenance costs. This paper introduces an integrated electronic block system and the field test results. The field test was carried out through a periodic inspection performed eight times from January to late August.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.39 no.4
• /
• pp.229-236
• /
• 2023

Maxillary bone defects may follow surgical treatment of benign and malignant tumors, trauma, and infection. Palatal defects often lead to problems with swallowing and pronunciation from the leakage of air into the nasal cavity and sinus. Obturators have been commonly used to solve these problems, but long-term use of the device may cause irritation of the oral mucosa or damage to the abutment teeth. Utilizing implants in the edentulous area for the fabrication of the obturators has gained attention. This case report describes a patient, who had undergone partial resection of the maxilla due to adenocarcinoma, in need of a new obturator after losing abutment teeth after long-term use of the previous obturator. Implants were placed in strategic locations, and an implant-retained maxillary obturator was fabricated, showing satisfactory results in the rehabilitation of multiple aspects, including palatal defect, masticatory function, swallowing, pronunciation, and aesthetics.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.3
• /
• pp.319-324
• /
• 2017

Patients with maxillectomy defects predisposed to not only difficulty in deglutition, mastication, speech but also psychological depression from impaired facial esthetics that affect life quality. Obturator prostheses play a important role in restoring the lost form, function and the quality of life for patients with maxillectomy defects. This clinical report presents the simplified approach to predict the degree of adequate facial support by Artificial palate which reflected from a maxillary interim obturator during the stabilization period after maxillectomy.

• Proceedings of the KIEE Conference
• /
• 2004.04a
• /
• pp.241-243
• /
• 2004

본 논문은 차상신호시스템의 설치시 기존의 자동폐색장치의 적용 가능성 및 개량 범위 등에 대해 분석하였다. 이는 주로 자동폐색장치의 특성 및 관련 폐색거리, 폐색신호와 차상신호의 혼용 운영 및 차상신호 적용시의 폐색신호 인터페이스 방안 등을 중점적으로 검토하였다.

• The Journal of Korean Academy of Prosthodontics
• /
• v.58 no.1
• /
• pp.30-34
• /
• 2020

Maxillectomy is performed to remove the tumor in the palate, maxillary sinus, buccal mucosa or nasal cavity. The resection range depends on the size and the extent of the tumor and it affects speech production or cause nasal regurgitation during feeding. Obturator can occlude an opening such as an oro-nasal fistula and protect the defect area. Successful reconstrucion of the patient's oral cavity who have gone over the maxillectomy is a difficult task. The condition and number of teeth, the remaining support area, and the extent of the defect area have a great influence on manufacturing the obturator. If these factors are disadvantageous, the prognosis of the prosthesis is uncertain. The final obturator must have a sufficient retention in the patient's oral cavity and must not irritate the surrounding tissue and support area where the resection was performed.In this case, a 55 year old female went through the maxillectomy and the only 3 teeth remained. And the retention of the maxillary prosthesis seems to be poor. So that, we fabricated the closed hollow obturator which has reduced weight compared to the conventional obturator. Consequently the closed hollow obturator can give better sealing and the adaptation.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.25 no.4
• /
• pp.329-336
• /
• 2009

In the case of congenital malformation, acquired trauma, or maxillectomy by neoplasm, the defect in maxilla is combined with nasal cavity, maxillary sinus and oral cavity. This results in abnormal function in pronunciation, mastication, and swallowing. In this situation, the purposes of prosthodontics are also applied. The purposes of obturator for acquired maxillary deficiency patients are restoring pronunciation, mastication, and swallowing, and make patients comfortable and esthetic satisfaction. Reducing weight of the obturator makes edentulous ridge heathy and functional. It also improves patients' comfort. Hollow obturator also reduces unnecessary stress because improves physiologic function, as it weights less than 6.55-33.06% compare to usual one. This case presents the double-processing method for maxillary obturator in the patient treated hemi-maxillectomy due to malignancy neoplasm. We report this case because the patient acquired functional and esthetic satisfaction from double-processing obturator.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.37 no.4
• /
• pp.281-293
• /
• 2021

Patients who went through maxillectomy can have severely impaired swallowing, mastication, and pronunciation functions because of palatal defects. Leakage occurs through the nasal cavity while eating, chewing becomes difficult due to the loss of teeth and alveolar ridges, and oral and nasal passages are not separated, leading to hyper-nasal sound, and significantly reducing the quality of life. To prosthetically reconstruct the defect, the weight of the obturator should be reduced as much as possible to minimize dropout because of gravity, and the bulb of the obturator should be properly extended into the defect to get additional retention and stability. In this case of a partially edentulous patient who underwent additional maxillary resection because of tumor recurrence, a metal framework was designed by applying the basic design principles of removable partial dentures. An obturator with improved retention, stability, and support was fabricated through functional impressions. The patient was satisfied with the improved facial expression, mastication, swallowing, and pronunciation, and showed stable occlusion and oral hygiene management during the follow-up period.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.4171-4176
• /
• 2012

The conventional block systems for railway signaling currently in operation in Korea have not been electrified or integrated and therefore there have been difficulties in terms of construction and maintenance. Two independent systems have been installed for ABS and LEU of ATP system (for speeded-up lines), although they deal with the same signaling information at the same location in order to control the trains. In these conventional ABS and LEU, a number of duplicate modules are installed in each device including lamp detection units and power supply units and it results increased manufacturing costs and maintenance efforts. This paper deals with the prototype development of integrated electronic block system with CPU-based digital control methods in order to overcome the limitations of the conventional ABS. The suggested system is the integration of the conventional ABS with LEU of ATP and it is also applicable for the non-ATP sections as well.

• 대한치과보철학회:학술대회논문집
• /
• 2006.04a
• /
• pp.88-88
• /
• 2006