• The Journal of the Korean dental association
• /
• v.36 no.4 s.347
• /
• pp.262-268
• /
• 1998

• Journal of Dental Rehabilitation and Applied Science
• /
• v.33 no.4
• /
• pp.278-283
• /
• 2017

Purpose: The aim of this study was to evaluate the interdental distances of anterior, premolar, and molar teeth at the cementoenamel junction (CEJ) and 2 mm below the CEJ in healthy natural dentition with cone-beam computerized tomography (cone-beam CT) in order to provide valuable data for ideal implant positioning relative to mesiodistal bone dimensions. Materials and Methods: Two hundred patients who visited Dental Hospital, Wonkwang University, who had natural dentition with healthy interdental papillae, and who underwent cone-beam CT were selected. The cone-beam CT images were converted to digital imaging and communication in medicine (DICOM) files and reconstructed in three-dimensional images. To standardize the cone-beam CT images, head reorientation was performed. All of the measurements were determined on the reconstructed panoramic images by three professionally trained dentists. Results: At the CEJ, the mean maxillary interdental distances were 1.84 mm (anterior teeth), 2.07 mm (premolar), and 2.08 mm (molar), and the mean mandibular interproximal distances were 1.55 mm (anterior teeth), 2.20 mm (premolar), and 2.36 mm (molar). At 2mm below the CEJ, the mean maxillary interdental distances were 2.19 mm (anterior teeth), 2.51 mm (premolar), and 2.60 mm (molar), and the mean mandibular interproximal distances were 1.86 mm (anterior teeth), 2.53 mm (premolar), and 3.01 mm (molar). Conclusion: The interdental distances in the natural dentition were larger at the posterior teeth than at the anterior teeth and also at 2 mm below the CEJ level compared with at the CEJ level. The distances between mandibular incisors were the narrowest and the distances between mandibular molars were the widest in the entire dentition.

• Journal of Oral Medicine and Pain
• /
• v.30 no.3
• /
• pp.361-373
• /
• 2005

Occlusal appliance therapy has been proven to be very useful and effective in reducing signs and symptoms of patients with TMD. However, there are no reports about the masticatory efficiency of the occlusal appliance. The purpose of this study was, first, to investigate the masticatory efficiency of the conventional stabilization appliance experimentally in normal healthy subjects, by comparing it with that of their natural dentition; and, second, to develop a modified stabilization appliance as an attempt to increase masticatory efficiency. Eleven subjects (mean age 25.3 years, range from 23 to 33) participated in this study. Six were men and five were women. They were healthy and had complete or near―complete natural dentition, and did not present with signs or symptoms of TMD. Two kinds of occlusal appliances―the conventional flat maxillary stabilization appliance (i.e., FSA) and a modified maxillary stabilization appliance with additional anatomic structures on its occlusal surface (i.e., ASA)―were made for every subject. Subjects chewed peanuts that were selected as a food to test the three masticatory conditions of the natural dentition, the ASA, and the FSA. The number of chewing strokes was counted during each 1-minute chewing period. Chewed peanut boluses were recovered and their hardness was measured by texture analysis. Statistical tests were performed. The following results were obtained. 1. The masticatory efficiency of the FSA was 38.6 percent that of the natural dentition. The efficiency of the ASA was 78.2 percent that of the natural dentition. 2. The number of chewing strokes in the natural dentition condition was measured to be 1.5 strokes per second. It decreased to 90 percent in the ASA and FSA conditions. These results indicate that the ASA could serve an improved masticatory capacity as well as its therapeutic effects in TMD. A clinical application of the ASA should be considered to extend the management of TMD patients.

• 대한치과보철학회:학술대회논문집
• /
• 1996.11a
• /
• pp.88-89
• /
• 1996

• The Journal of Korean Academy of Prosthodontics
• /
• v.61 no.3
• /
• pp.198-203
• /
• 2023

Purpose. The aim of this study was to evaluate the proximal contact with a dental floss compared to a celluloid strip and a metal strip in normal dental arch and investigate what the most effective method for measuring is. Materials and methods. The subjects of this study was consisted with 20 healthy adults (10 males and 10 females) who had normal dentition. A dentist with more than 5 years of clinical experience evaluated the proximal contacts using a dental floss method, a celluloid strip method, and a metal strip method. Statistical analysis were performed by the use of Mann-Whitney U test. A P-value < .05 was considered statistically significant in all analysis. In addition, in the evaluation of proximal contact using a dental floss, the measurement of proximal contact using a celluloid strip and a metal strip was compared. Results. 80 % of all proximal contact was proper. Proper proximal contact was observed at the posterior area compared to the anterior area (P < .05). And male had proper proximal contact at the anterior area, female had proper proximal contact at the posterior area (P < .05). The consistency analysis between the results of the celluloid strip and the metal strip experiment on the results obtained from the floss using the consistency scale Kappa index shows that using celluloid strip is more advantageous than using the metal strip. Conclusion. Only 80% of all proximal contact was proper. Using celluloid strips with various thickness for evaluating of proximal contact is considered to be helpful for accurate measuring of proximal contact.

• The Journal of the Korean dental association
• /
• v.19 no.3 s.142
• /
• pp.253-260
• /
• 1981

• Venture DIGEST
• /
• s.110
• /
• pp.38-39
• /
• 2007

치열한 자본주의 아래의 기업활동은 경쟁의 연속이다. 현재 세계 50대 기업 중 50년 전에도 존재하였던 기업은 손꼽을 정도라고 하니 자본주의하의 경쟁이 얼마나 치열한 것인지 알 수 있다. 이에 기업은 서로간의 연합, 협정, 결합 등을 통해 경쟁을 회피하려는 동기를 가지게 된다. 그러나 시장경쟁이 줄어들면 자연히 시장에서의 독점적 지위를 보장받는 데만 집중하여 궁극적으로 시장에서 독과점의 위치를 차지하게 된다고 보는 시각도 존재하고 있다. 본 호에서는 기업결합의 페해를 막기 위해 법률상에서 기업결합이 어떻게 규제되고 있는지 살펴 본다.

• The Microorganisms and Industry
• /
• v.13 no.2
• /
• pp.18-19
• /
• 1987

첨단과학기술의 육성은 기술도입과 그 모방으로 이룰 수가 없다. 우리는 아직도 많은 기술과 소재, 부품들을 경쟁국인 선진국에 의존하지 않으면 안된다. 새로운 것을 발견하고, 발명하는 것에 대한 능력과 경험에 있어서 선진국과 우리의 격차는 아직도 크다. 발견과 벌명은 튼튼한 기초과학의 토대위에 이루어지는 것이다. 기초과학은 자연현상을 지배하는 원리를 탐구하는 학문을 말한다. 이러한 기초과학의 탐구는 자연의 법칙을 이해하는데 그치지 않고 새로운 것을 발명하고 창조하는데 응용할 수 있는 방법을 고안하여 준다. 따라서 우리가 치열한 국제경재에서 이겨나가기 위해서는 광범위한 기초과학지식과 탐구능력, 그리고 풍부한 창의력으로 무장된 고급인력을 국내에서 많이 길러내어야 한다.

• Journal of Technologic Dentistry
• /
• v.2 no.1
• /
• pp.35-38
• /
• 1980

이 기술은 레진(acrylic resin) 또는 의과용 도재(dental porcelain)에 의한 치아 색깔의 전장부위를 갖고 있는 금속구치 block(metal posterior tooth block)의 개조에 대한 기술의 일면이다. 이 기술은 모든 가철식 보철물(removable dental restoration)에 적용할 수 있으며 특히 자연치열(natural dentition) 대합치에 가철식 국부의치(removable partial denture)를 갖고 있는 만성 이갈음 환자(chronic bruxing patient)에 적용할 수 있다.

• Life and Agrochemicals
• /
• s.257
• /
• pp.52-55
• /
• 2010

2차 세계대전후 유기합성살충제공업이 구미 유명화학공업회사들 사이에서 일제히 개시되었다. 그 당시 농약연구의 현저한 특징은 처음부터 초거대 연구소가 지어져 스타트 시점부터 치열한 생존경쟁을 했다는 것이다. 그 결과 현재 극히 소수만 이 세상에 살아남아 있다는 것이다.