• 치과방사선
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• 제21권2호
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• pp.275-285
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• 1991

The clinical and radiographic features of 655 congenitally missing teeth were studied with full mouth periapical radiograms and/or pantomograms from 368 persons visited the Department of Oral Radiology, Infirmary of Dentistry, Kyung Hee University during January 1981 to December 1989. The obtained results were as follows: 1. The prevalence of congenitally missing teeth was revealed to be 8.75% in total examined persons, and there was a higher prevalence in females (9.5%) than in males (8.0%). 2. The most frequently missing teeth were mandibular second premolars (24.6%), followed by mandibular lateral incisors (21.7%), maxillary second premolars (16.2%), and maxillary lateral incisors (11.5%). 3. There was a higher prevalence in the mandible (60.3%) than in the maxilla (39.7%), and no significant differences between right (49.65%) and left (50.35%) side. 4. In number of congenitally missing teeth per person, 54.6% had one missing tooth, and 32.9% had two missing teeth. 5. In persons with one or two congenitally missing teeth, the most frequently missing tooth was mandibular lateral incisor, and the second premolar was the tooth most frequently missing in those persons with more than three congenitally missing teeth.

• 대한소아치과학회지
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• 제46권3호
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• pp.239-246
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• 2019

이 연구의 목적은 항암 치료를 받은 후 소아환자에서 나타나는 치아의 발육장애의 유병률에 대해 조사하고, 항암 치료의 시기, 치료방법, 그리고 치료 기간에 따라 어떤 차이를 보이는 지 알아보고자 하였다. 임상 및 방사선학적 기록이 존재하는 93명의 소아암 환자에 대해 치아의 수, 치아의 형태, 치근의 형태, 치아의 발달 정도를 평가하였다. 조사된 치아의 형성장애는 전체 환자의 61.3%에서 발견되었고, 이중에는 치근의 형태이상이 31.2%로 가장 많이 관찰되었다. 6세 이후에 항암치료를 시작한 환아보다 6세 이전에 항암 치료를 시작한 환아에서 결손치(p = 0.029)와 왜소치(p = 0.003) 수가 더 많았으며, 이는 통계적으로 유의한 차이를 나타냈다. 화학요법과 방사선요법을 병행한 경우 화학요법만을 시행한 경우보다 결손치(p = 0.030), 왜소치(p = 0.046), 그리고 치근형태이상(p = 0.009)이 더 높은 빈도로 관찰되었고, 이는 통계적으로 유의한 차이를 나타냈다. 18개월 미만의 항암 치료 기간을 경험한 환아에 비해 18개월 이상 항암 치료를 받은 환아에서 결손치(p = 0.032), 왜소치(p = 0.011), 치근형태이상(p = 0.025), 그리고 총 치아이상(p = 0.036)의 수가 더 많았으며, 이는 통계적으로 유의한 차이를 나타냈다. 결론적으로, 항암치료를 받은 소아환자에서 더 빠른 항암치료 개시시기, 화학 및 방사선 요법의 병행, 그리고 더 긴 항암치료 기간이 치아 형성 중의 이상소견을 증가시켰다.

• 한국치위생학회지
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• 제18권6호
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• pp.921-932
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• 2018

Objectives: The aim of this study was to investigate the number of existing permanent teeth and the denture usage status in elderly adults aged 65 years and above living in metropolitan cities and to confirm the degree of oral health inequality caused by the differences in oral conditions in each metropolitan city using the Lorenz curve and the Gini coefficient. Methods: The raw data for the analysis were obtained from the dataset of the sixth Korea National Health and Nutrition Examination Survey conducted between 2013 and 2015. The subjects included 1,764 people who underwent oral examination and answered questions. The complex samples general linear model was used to analyze the number of existing permanent teeth adjusted for age and monthly household income. The proportion of edentulousness and the denture status was analyzed using complex samples crosstabs. Results: The number of existing permanent teeth in the elderly adults aged 65 years and above was lowest in Ulsan (15.41) and highest in Gwangju (20.44). The proportion of edentulousness was highest in Busan (14.5%) and lowest in Daejeon (4.0%). With regard to the proportion of denture users, Busan had the highest tendency for denture usage (50.4%) and Gwangju had the lowest tendency (34.9) (p=0.172). The Gini's coefficient for the number of existing teeth was lowest in Busan (0.332). Oral health inequality was most severe in metropolitan cities. Conclusions: We found that oral health inequality exists among elderly adults living in the metropolitan cities of Korea using the Lorenz curve and Gini's coefficient.

• Applied Microscopy
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• 제18권2호
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• pp.132-140
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• 1988

The radulae of six species of bithyniid snails, Bithynia striatula, B. tentaculate, B. siamensis, B. leachi, Gabbia misella and G. australis, were observed by SEM. The radular formula of all the bithyniids studied was 2 : 1 : 1 : 1 : 2. The all teeth were multicuspid and the central teeth had numerous basal denticles. The mesocones of the central and lateral teeth were spade or arrow-head shape. The mesocones of the central teeth and the lateral teeth of B. leachi, G. misella and G. australis were slightly larger than the other cusps in contrast of those of the other species. Number of cusp was varied by the specimen and the species.

• 대한치과교정학회지
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• 제10권1호
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• pp.55-64
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• 1980

The purpose of this study was to investigate the interrelationship of the experimental group and control group by analyzing case histories, intraoral radiographs, orthopantomographs, intraoral slide films and dental casts. The data for this study were complied from 654 outpatients of the Department of Orthodontics, Seoul National University Hospital. The following conclusions were obtained. 1. When one or more thins molar teeth were congenitally missing, the incidence of the other congenitally missing teeth was high. 2. The frequency of congenitally missing teeth was comparatively higher in male, maxilla, class II and class III. 3. The congenitally missing srea of the third molar by Angle's classification was not significant. 4. The order of frequency of congenitally missing teeth was the third molar, the second premolar, the lateral incisor, the first premolar, the central incisor, the canine, the first molar, the second molar.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.126-129
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• 1991

The effect of each tooth for optimal design of Hybrid permanent magnet step motor is presented on this paper. For this consideration, Hybrid permanent magnet step motor was designed in the first consideration tooth structure on the stator and the rotor and poles structure, as number of teeth on the stator and the rotor and slot depth and pitch of teeth, simulated by AutoLISP. During actual rotating, a chracteristic of Hybrid permanent magnet step motor which designed by AutoLISP program is considered. A chracteristic of Hybrid permanent magnet step motor is considered in change each variable, also. As a result, it was found that characteristic of Hybrid permanent magnet step motor changed in accordance with tooth structure and number of teeth and optimal design is possible by AutoLISP.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.71-75
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• 1980

The purpose of this study was to determine the close relation between clinical symptom and histopathologic finding in pulp. 20 samples of pulp tissue were collected from badly decayed teeth with considerable pulp vitality. Hemogram was also made with the first drop of bleedieg after total pulp extirpation (10cases) and vital pulpotomy(10cases). Histologic specimen was made routinely with extirpated pulp and stained by H&E and P.A.S. Stains. The results under microsopic examination were as follows; 1. Hemogram obtained from dental pulp with acute inflammation revealed increase of polymorphonuclear leukocyte in number, more lymphocytes and monocytes. 2. Hemogram from pulp with chronic inflammation shown the number of lymphocyte and monocyte was remarkably increased. 3. Histologi specimen obtained from teeth with severe clinical symptome showed polymorphonuclear leukocyte infiltration and the hemogram also showed polymorphonuclear leukocytes. 4. Specimen from teeth with moderate symptom showed lymphocyte infiltration and vessel dilatation underneath decayed area. Erythrocytes were massively accumulated inside of the vessel wall.

• 대한치과의사협회지
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• 제12권2호
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• pp.107-111
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• 1974

In order to collect some necessary data to promote correcting the toothbrushing technic on the Korean public, the author had examined the number of present teeth on which had cervical abrasion and the most basic home dental care in 2,000 Korean male and female adults from 19 to 52 years in the age. Then, the cervical abrasion experience rate and the cervical abrasion experience teeth rate were calculated and evaluated. The obtained results were as follows: 1. Cervical abrasion experience rate was 32.45% 2. Cervical abrasion experience rate was gradually increased by ageing. 3. Cervical abrasion experience rate in male adults was higher than that in female adults. 4. Cervical abrasion experience rate in the lower jaw was higher than that in the upper jaw. 5. Cervical abrasion experience rate of the teeth at the right side was higher than that of the teeth at the left side. 6. Cervical abrasion experience teeth rate was 3.82%. 7. Cervical abrasion experience rate was highest on the first bicuspid, and followed in the sequence of the second bicuspid, canine, first molar, incisors, and 2nd and 3rd molars.

• 대한소아치과학회지
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• 제35권2호
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• pp.333-338
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• 2008

과잉치란 정상에 비해 많은 수의 치아를 일컫는 것으로 유치열기와 혼합치열기에 발생하며, 여러 가지 임상적 문제를 일으킬 수 있다. 특히 상악 전치부의 과잉치는 상악 전치의 맹출 장애 및 전위, 정중부의 치간 이개, 치근 흡수, 함치성낭종 형성 등의 문제를 유발할 수 있으므로 조기에 진단하고, 과잉치의 위치 및 수, 형태에 따라 적절한 치료를 시행하는 것이 중요하다. 이 증례는 상악 전치부에 네 개의 과잉치가 영구치의 맹출을 방해하고 있는 경우로, 발거 시 합병증을 최소화하기 위하여 두 단계로 나누어 발거하였다. 컴퓨터 단층 촬영에서 네 개의 과잉치가 주위의 영구치 맹출을 방해하고 있었고, 그 중 두 개의 과잉치는 절치 치배에 매우 근접해 있었다. 네 개의 과잉치를 동시에 제거할 경우 영구 치배에 손상을 줄 위험이 있으므로 두 개의 역위 매복된 원추형의 과잉치만 먼저 발거하였다. 남은 두 개의 과잉치는 위치가 변화되기를 기다린 후 두 번째 발거 수술을 시행하여, 주위 절치 치배에 손상을 가하지 않고 치조골 삭제를 적게 하여 합병증 발생을 줄일 수 있었다.

• 한국치위생학회지
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• 제19권1호
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• pp.65-78
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• 2019

Objectives: This study was conducted to characterize the impact of cognitive function and oral health status on mastication in senior citizens, ${\geq}65$ years of age, using senior centers in the city of Wonju, South Korea. Methods: A cross-sectional study consisting of a simple oral examination and survey questionnaires was performed in 154 individuals. General characteristics, subjective masticatory function, objective masticatory function, cognitive function, and oral health status were collected as variables. Correlation and multiple linear regression analyses were conducted. A p-value of <0.05 was considered to be statistically significant. Results: The subjective masticatory function was scored using the 5-point Likert scale. When subjective masticatory function was analyzed in groups according to cognitive function, the mean subjective masticatory function scores were 4.31, 4.09, and 3.29 in the normal group (cognitive score of ${\geq}16$), suspected dementia group (cognitive score of 1215), and mild dementia group (cognitive score of ${\leq}11$), respectively. Thus, subjective masticatory function decreased along with decreasing cognitive function. When cognitive function, subjective masticatory function, and objective masticatory function were compared with indicators of oral health status (number of functional teeth, oral dryness), subjective masticatory function exhibited a significant positive correlation with objective masticatory function (r=0.635, p<0.01), cognitive function (r=0.292, p<0.01), and total number of functional teeth, including prosthetic appliances (dentures) (r=0.305, p<0.01). According to the regression analysis, age, sex, number of functional teeth, and cognitive function affected subjective masticatory function. Conclusions: The results of this study revealed that age, sex, number of functional teeth, and cognitive function affected subjective masticatory function, whereas oral dryness did not. Therefore, dental professionals must consider subjective masticatory function when providing oral care in senior patients with low cognitive function.