• Journal of Oral Medicine and Pain
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• v.20 no.1
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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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• v.17 no.2
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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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• v.16 no.1
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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.

• Journal of dental hygiene science
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• v.6 no.2
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• pp.55-63
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• 2006

The purpose of this study was to provide the basic data for preventing dental caries, and maintaining and enhancing oral health. The subjects of this study were 138 male and female students who were in the 6th grade of elementary schools in Gimpo city. This study investigated the number of decayed tooth and the factors related to the number of decayed tooth, by using the results of questionnaire and oral health survey over such subjects. So, this study obtained the following conclusions. 1. For the number of decayed tooth, 'nothing(D = 0)' was the highest as 37.7%, and 'from two to three' was 23.9%, 'more than four' was 21%, and 'one' was 17.4% in order. 2. For the frequency of visiting dental clinics within the last one year, 'one to two times' was the highest as 52.2%, and the children who have not visited dental clinics even one time during one year were 23.9%. 3. For average daily tooth brushing frequency, 'two times' was the highest as 71.7%. For the use of oral health devices besides toothbrushes, 'I don't use' was the highest as 54.3%. For the experience of sealant and fluoride application, 'nothing' was the highest as 86.9% and 71.3% respectively. For the recognition on the use of fluoride dentifrice, 'I don't know' was the highest as 66.9%. 4. The socio-demographic factors related to the number of decayed tooth were mother's age, mother's background, mother's employment, and after-school fosterer(p > 0.05). 5. The oral health care factors related to the number of decayed tooth were average daily tooth brushing frequency, the use of oral health devices besides toothbrushes, and the experience of fluoride application.(p > 0.05) 6. The snack intake factors related to the number of decayed tooth were tooth care foods intake frequency and decaying foods intake frequency(p > 0.05). 7. The oral health belief item related to the number of decayed tooth was susceptibility(p > 0.05). 8. According to the results of regression analysis, the less mother was employed, the more the average daily tooth brushing frequency was, the more the tooth care foods intake frequency was, the less the decaying foods intake frequency was, and the higher susceptibility was, the lower the number of decayed tooth. 9. In order to prevent and cure early the dental caries which occur frequently in elementary school students, the establishment of oral health centers within schools should be expanded to promote tooth brushing instruction, fluoride solution rinsing, diet control, periodic oral examination.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.3
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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.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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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.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.6
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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.

• Journal of Korean society of Dental Hygiene
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• v.19 no.2
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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.

• Journal of Korean society of Dental Hygiene
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• v.20 no.5
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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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• v.5 no.1
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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.