• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.133-135
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• 1996

This paper deals with the effect of teeth number variation in permanent Magnet DC motor. As teeth number varies, both flux density distribution and winding pitch are influenced, which is closely related to torque-speed characteristics, output power, and efficiency. In this study, motor design carried out using finite element method, and prototype motors were manufactured to test their performance analysis. In spite of torque ripple due to cogging effect better characteristic of machine using small teeth number was recorded than the motors with large number of rotor teeth. One of that reasons is caused by adopting large coil-length due to large number of teeth, i. e. large coil-pitch.

• Mass Spectrometry Letters
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• 제8권4호
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• pp.105-108
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• 2017

Recently, deciduous teeth have been proposed as a promising biomatrix for estimating internal and external chemical exposures of an individual from prenatal periods to early childhood. Therefore, detection of organic chemicals in teeth has received increasing attention. Organic materials in tooth matrix are mostly collagen type proteins, but lipids and other small organic chemicals are also present in the tooth matrix. In this study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) was employed to obtain lipid fingerprints from deciduous teeth. Phospholipids and triacylglcerols (TAGs) from deciduous teeth were successfully detected by MALDI MS with 2,5-dihydroxybenzoic acid (DHB) or gold nanoparticle (AuNP) as a matrix.

• Journal of Oral Medicine and Pain
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• 제43권3호
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• pp.92-96
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• 2018

A 39-year-old male presented with severe pain in right posterior mandibular teeth and temporal area. Initially, the pain in the mandibular teeth was moderate, but the concomitant headache was unbearably severe. His medical history was non-contributory. The clinical and radiographic examination failed to reveal any pathology in the region. There was no tenderness to palpation in the temporalis and masseter muscles or temporomandibular joints. The clinical impression was migraine. The pain in the teeth and headache were aborted using ergotamine tartrate and sumatriptan succinate. Atenolol prevented further pain, while amitriptyline and imipramine had no effect. Migraine can present as non-odontogenic pain in the mandibular teeth, although not as frequently as in the maxillary teeth. A correct diagnosis is essential to avoid unnecessary dental treatments and to manage pain effectively. Clinicians should be able to identify migraine with non-odontogenic dental pain and establish a proper diagnosis through a comprehensive evaluation.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.11-15
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• 1987

Thirty maxillary second premolars were fixed, decalcified, washed and embedded in celloidin to observe the root canal size and morphology at apical 5mm area. The results were as follows: 1. Single canaled teeth and two canaled teeth were approximately equal numbered. 2. Single canaled teeth have round canal but two canaled teeth have long, slender buccal canal and ovoid lingual canal. 3. The canal size of single canaled teeth was $380{\pm}30{\mu}m,\;340{\pm}22{\mu}m$, but that of buccal canal of two canaled teeth was $360{\pm}32{\mu}m,\;240{\pm}28{\mu}m$, lingual canal was $330{\pm}28{\mu}m,\;280{\pm}20{\mu}m$.

• Mass Spectrometry Letters
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• 제9권4호
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• pp.110-114
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• 2018

Since accumulation of chemicals in deciduous teeth can occur from the second trimester of fetal development to shedding, a deciduous tooth has been considered as an attractive biomatrix for estimating individual chemical exposures recently. Therefore, detection of organic chemicals from teeth has received an increasing attention in exposomics research. Most previous studies on organic chemical analysis of teeth not only focused on a few targeted chemicals but also ignored potential contaminants from an enamel surface or a dental pulp. Recently, our group started developing a multi-class organic analysis method for deciduous teeth and tried to find a proper incubation condition of tooth materials. Our results showed that incubation with methanolic HCl provided the best performance among tested.

• 치위생과학회지
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• 제11권3호
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• pp.205-211
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• 2011

본 연구는 경기도 C치과의원에서 2010년 1월부터 12월까지 1년 동안 18-24개월에 해당되는 293명의 영유아 구강검진 결과표와 부모가 작성한 문진표를 토대로 구강건강상태와 구강건강행태 및 우식성 식품섭취가 우식치와 탈회치에 미치는 영향을 조사하였으며, 결과는 다음과 같다. 1. 18-20개월 영유아는 탈회치의 비율이 36.4%로 높고, 23-24개월 영유아는 우식치의 비율이 37.0%로 높게 나타났다. 2. 우유병을 뗀 여부는 탈회치와 우식치의 발생에 관련이 있다(p<.001). 3. 구강상태에서 썩은치아와 뿌연치아에 대해 부모가 인지하는 것으로 나타났다. 4. 식품군 중에서 2군(탄산음료/청량음료/가당 과일 쥬스)이 탈회치와 우식치와 관련이 있다(p<.001), 4군(케이크/과자/도우넛/말린과일/바나나), 5군(캐러멜/사탕류/초코렛바)은 탈회치와 관련이 있다(p<.001). 5. 구강검진 결과, 치아치료는 21-22개월(89.3%)에서, 예방치료와 치면세균막 제거는 18-20개월(94.5%)에서 가장 높게 필요한 것으로 나타났다. 이상의 결과를 통해 보면, 생후 18-24개월은 구강건강관리에 주의를 요하는 시기이므로 영유아 검진시에 부모의 체계화된 구강보건교육이 필요할 것으로 사료된다.

• 대한치과의사협회지
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• 제12권8호
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• pp.567-571
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• 1974

The author have had a case of Anodontia Partialis in 15 year old, Korean female. 1. The disturbance was shown on the mandible development and mastication. 2. No general disturbances were found. 3. The teeth were normally shaped, no torsiversion had taken place, and the teeth were lining up normally. 4. X-Ray examination revealed that no teeth were unerupted.

• 대한치과교정학회지
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• 제47권1호
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• pp.21-30
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• 2017

Objective: The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods: Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions: Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.

• 인지과학
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• 제18권4호
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• pp.445-455
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• 2007

본 논문은 주성분분석기법을 이용한 치아의 다면특징을 기반으로 한 새로운 생체 식별시스템을 제안한다. 치아의 다면 특징들은 정면치아와 좌측, 우측 치아들로 이루어진다. 우리는 실생활 환경에서 보안 접속을 위하여 치아를 이용한 생체식별을 목표로 한다. 다면 치아 영상들은 특별히 고안된 실험환경에서 획득되었으며, 개인 식별을 위한 특징으로 42개의 주성분이 개발되었다. 개인 식별은 학습된 다면치아와 회전된 다면치아 사이의 최소근접기법에 의해 계산되었다. 2도 회전 후의 다면치아 인식성능은 평균값으로 좌측면 치아 95.2%, 우측면 치아 91.3%을 보였다.

• 보건교육건강증진학회지
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• 제14권1호
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• pp.63-72
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• 1997

In order to develop the programme for the improvement of dental health among primary school children, epidemiological survey to examine dental caries status was conducted among primary school children in Changwon, Korea. We sampled 2 primary schools and surveyed children from first to sixth grade aged 6-11 years. All samples were 3,206 consisted of 1,715 males and 1,491 females. We assessed caries prevalence on permanent teeth. 1. Children with caries experience on permanent teeth were 15.1% at 1st grade, 48.2% at 2nd grade, 73.8% at 3rd grade, 75.6% at 4th grade, 76.8% at 5th grade, 77.4% at 6th grade. 2. Decayed, Missing and Filled teeth were 0.31 at 1st grade, 1.16 at 2nd grade, 2.12 at 3rd grade, 2.38 at 4th grade, 2.50 at 5th grade, 2.69 at 6th grade. 3. Decayed teeth among Decayed, Missing and Filled teeth were totally 63.4%. Filled teeth among Decayed, Missing and Filled teeth were totally 36.6%. 4. Community dental health programmmes including water fluoridation, fluoride mouth rinsing, use of fluoride-containing toothpastes and fissure sealants should be developed to prevent dental caries among school children. 5. School incremental dental care programme should be also developed to prevent and treat children's dental caries by use of dentists and oral hygienists.