• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.133-139
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• 1995

The aim of this study was to investigate the state of anterior tooth contacts in patient with internal derangement of TMJ. We have investigated the change of the number of tooth contacts after conservative treatment including stabilization spint in 83 patients with TMJ internal derangemnet who visited the Orofacial Pain Clinic, Dept of Oral Diagnosis, Seoul National University Dental Hospital. The obtained results were as follows : 1. The gender ratio of patients was 1:3.7(M:F) 2. The number of patients with bony changes in TMJ was 17(20.5%) 3. The number of patients with absence of incisor tooth contacts was 73(88%) 4. The number of Tooth contacts after treatment was decreased compared with that before treatment in both groups. However there was no significant difference between groups 5. There was the decrease in the number of tooth contacts in 12(76%) of 17 patients with bony changes in TMJ and in 23(34.8%) of 66 patients without bony changes in TMJ. 6. The ratio of patients who showed the decrease of the number of tooth contacts was higher in patients with bony changes in TMJ than patients without bony changes in TMJ. 7. After conservative treatments with stabilization splints in patients with TMJ internal derangement, the possibility of the decrease in the number of tooth contacts had no relationship with the presence of incisor tooth contacts. However, the incidence was higher in patients with bony changes in TMJ.

• The Korean Journal of Physiology and Pharmacology
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• 제17권2호
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• pp.121-125
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• 2013

The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth.

• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.280-286
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• 2024

In this paper, layered UNet with warmup and dropout tricks was used to segment teeth instantly by using data labeled for each individual tooth and increase performance of the result. The layered UNet proposed before showed very good performance in tooth segmentation without distinguishing tooth number. To do instance segmentation of teeth, we labeled teeth CBCT data according to tooth numbering system which is devised by FDI World Dental Federation notation. Colors for labeled teeth are like AI-Hub teeth dataset. Simulation results show that layered UNet does also segment very well for each tooth distinguishing tooth number by color. Layered UNet model using warmup trick was the best with IoU values of 0.80 and 0.77 for training, validation data. To increase the performance of instance segmentation of teeth, we need more labeled data later. The results of this paper can be used to develop medical software that requires tooth recognition, such as orthodontic treatment, wisdom tooth extraction, and implant surgery.

• 치위생과학회지
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• 제6권2호
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• pp.55-63
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• 2006

본 연구는 향후 치아우식증 예방을 예방하고 구강건강을 유지 증진시키는데 필요한 기초자료를 제공하고자 하였으며, 김포시 면단위에 소재하는 초등학교 6학년 남 녀 138명을 대상으로 설문지 및 학교 구강검사 결과를 이용하여 우식치아수 및 우식치아수와 관련있는 요인을 조사하여 다음과 같은 결론을 얻었다. 1. 우식치아가 전혀 없는 경우가 응답자의 37.7%로 가장 많았고, '2-3개' 23.9%, '4개 이상' 21%, '1개'는 17.4%이였다. 2. 최근 1년동안 치과의료기관 방문횟수는 1-2회가 52.2%로 가장 많았고, 23.9%는 1년 동안 치과의료기관을 한번도 방문하지 않았다. 3. 하루 평균 잇솔질 횟수에서 2회는 71.7%였고, 54.3%는 잇솔 외 구강관리용품을 전혀 사용하지 않았으며, 86.9%와 71.3%는 각각 치면열구전색과 불소도포 경험이 전혀 없었고, 66.9%는 현재 사용하고 있는 세치제에 불소 배합여부를 전혀 인식하지 못하고 있었다. 4. 우식치아수와 관련있는 사회 인구학적 요인으로는 모친 연령, 모친 최종학력, 모친 취업여부, 하교 후 돌봐주는 사람이었다(p > 0.05). 5. 우식치아수와 관련있는 구강건강행위 요인으로는 하루 평균 잇솔질 횟수, 잇솔 외 구강관리용품 사용, 불소도포 경험이었다(p > 0.05). 6. 우식치아수와 관련있는 간식섭취요인으로는 치아보호식품과 우식성식품 섭취 횟수였다(p >0.05). 7. 우식치아수와 관련있는 구강건강신념항목은 감수성으로 나타났다(p > 0.05). 8. 회귀분석 결과 모친이 미취업이고, 하루 평균 잇솔질 횟수가 많으며, 치아보호식품 섭취횟수가 많고, 우식성 식품섭취가 적으며, 감수성이 낮을수록 우식치아수가 적은 경향을 보였다. 9. 초등학교 아동들에게 많이 발생되는 치아우식증을 예방하고 조기치료를 하기 위하여 학교 내 구강보건실 설치를 확대하며, 집단 구강검사를 통해 구강병을 초기단계에서 발견하여 치료로 연결시키고, 잇솔질 교습 및 불소용액 양치, 식이조절 등이 추진되어야 할 것이다.

• 오토저널
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• 제6권3호
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• pp.45-54
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• 1984

Bending strength of an internal gear tooth is discussed as tooth form factor taking into account the actual stress magnitude. Stress analysis was carried out by the finite element method(FEM) for the calculation of tooth form factor of an internal gear. This paper also investigated the influences of number of teeth and addendum modification coefficient of the internal gear and the influences of number of teeth, addendum modification coefficient, pressure angle, radius of rounding of tooth tip, and bottom clearance coefficient of the pinion-shaped cutter on tooth form factor of internal gear. Generalizing the resultant data, a simple formula for the tooth form factor of an internal gear was derived for the calculation of tooth bending strength of an internal gear.

• 한국정밀공학회지
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• 제22권4호
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• pp.159-166
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• 2005

This study deals with the correction of gear tooth profile error by finish roll forming. First, we experimentally confirmed that the tooth profile error is a synthesis of the concave error and the pressure angle error. Since various types of tooth profile errors appear in the experiments, we introduced evaluation parameters for rolling gears to objectively evaluate profile quality. Using these evaluation parameters, we clarified the relationship among the tooth profile error, the addendum modification factor (A. M. factor), and the tool loading force. We verified the character of concave error, pressure angle error, tool loading force and number of cycles of finish roll forming by using a forced displacement method. This study makes clear that tool loading force and number of cycles of finish roll forming are very important factors that affect involute tooth profile error. The results of the experiment and analysis show that the proposed method reduces concave and pressure angle errors.

• 한국공작기계학회논문집
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• 제13권6호
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• pp.17-22
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• 2004

A study for investigating the effects of the cutting conditions (radial depth of cut feed per tooth) and the number of tooth on the side wall of prismatically milled workpiece is described. This study is available not only for understanding the geometrical characteristics of the end milled side wall but also for finding the optimal cutting conditions. In this work, the side wall geometry was characterized by the straightness and the location of maximum peak point. Through this study, it was revealed that the geometrical characteristics of the end milled side wall are strongly related to the material removal per tooth and the number of tooth.

• 한국치위생학회지
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• 제19권2호
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• pp.161-172
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• 2019

Objectives: This study aimed to analyze the correlation between oral function, oral environment, and brain cognitive function in the elderly. Methods: The subjects were 60 users of senior community center and elderly day care center. The survey was conducted from November to December 2018. Subjects were assessed by oral examination and myofunction test. Oral myofunction was measured using $IOPI^R$ and Lip de $Cum^R$. Survey data were analyzed using the statistical programs of PASW Statistics ver. 18.0. Results: Tongue muscle strength and lips muscle strength was higher in males than in females. The tongue and lip strengths were higher in the <81 years old group than the ${\geq}81$ years old group. Functional tooth analysis showed that there was a ${\geq}15$ teeth group ($40.91{\pm}7.36$) and a <15 teeth group ($32.52{\pm}7.14$). Lip muscle strength analysis showed that the ${\geq}15$ teeth group ($10.54{\pm}3.40$) was higher than the <15 teeth group ($8.20{\pm}2.41$, p<0.05). Tongue muscle strength, lumbar muscle strength, and functional tooth number were lower in the elderly subjects with mild cognitive impairment. Cognitive function was significantly correlated with functional tooth number (r=0.386, p<0.001), tongue strength (r=0.478, p<0.001), and lip strength (r=0.281, p<0.05). Tongue strength was significantly correlated with lip strength (r=0.360, p<0.001) and functional tooth number (r=0.633, p<0.001). Lip strength was significantly correlated with functional tooth number (r=0.376, p<0.001). Conclusions: These results showed that age and functional tooth number influenced oral muscle strength and that the number of functional teeth and oral muscle strength were low in the elderly with mild cognitive impairment. Oral myofunction training and oral care program are suggested to improve the quality of life of the elderly.

• 한국치위생학회지
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• 제20권5호
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• pp.545-559
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• 2020

Objectives: The purpose of this study was to systematically analyze and examine the relationship between the number of lost teeth and quality of life (QoL) among elderly. Methods: Papers published in Korean and English between 2000 and 2020 were searched. Relevant papers were selected by two independent readers according to predefined exclusion criteria. Quality assessment and consistency tests were conducted using ROBIS. Results: Twelve of the 854 studies were targeted, and the analysis confirmed that tooth loss was related to a decrease in the QoL in 11 studies. Tooth loss negatively affected the QoL among the elderly. However, one study indicated that the QoL and number of teeth were not related. Rather, dry mouth affected the QoL, and cavities caused by oral dryness led to tooth loss. Most of the selected studies indicated that the QoL of elderly individuals with a single tooth was higher than that of those with no teeth. Conclusions: This study provides strong evidence that tooth loss in the elderly is associated with impairment of QoL.

• The Journal of Advanced Prosthodontics
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• 제5권1호
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• pp.51-57
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• 2013

PURPOSE. The purpose of this study was to to analyze the effect of Type 2 diabetes on tooth mortality, implant treatment and prosthetic status. MATERIALS AND METHODS. 275 Type 2 diabetics and 300 non-diabetics, aged 40-80 years were selected for analysis. The assessment of number of teeth, missing teeth, fixed prostheses (bridge pontics), implants using panoramic radiographs and dental records were carried out. RESULTS. Diabetes mellitus (DM) patients had a higher number of missing teeth (P<.05) and placed implants (P=.074), age (P<.05), male gender percentage (P=.042), smoker percentage (P<.05) than non-DM patients. In univariate analysis, the patients in older group showed significantly higher number of tooth loss rate at the first dental examination than the patients in younger group. Tooth loss rate of smokers did not show higher value than that of non-smokers. When multiple variables including DM, age, smoking, gender were considered together, diabetics and older group patients showed significantly higher tooth loss rate at the first dental examination than non-diabetics and younger group patients, respectively. Smokers and male group did not show a significant difference than nonsmokers and female group, respectively. CONCLUSION. Tooth mortality and implant treatment rate were significantly higher in the DM group as indicated by univariate and multivariate logistic regression analysis. Old age groups showed significantly higher odds ratios and tooth loss rate. As diabetics showed the higher tooth loss rate than non-diabetics, diabetics also had more implant restorations than non-diabetics.