• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.123-132
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• 1980

The author conducted a dental survey of a college girl students and compared with that of E college students 10 years ago which based on the same criteria. The items of this survey included the prevalence of dental caries, DMFT and the kinds of restored material. All college students 1,414 were examined in May 1978, with the recommended criteria and method of W.H.O.. Among them, the data of 1,393 were analyzed for this study. The following results were obtained: 1. The average number of present teeth were 28.97${\pm}$1.64. 2. The prevalence of dental caries was 84.92% and D.M.F. index was 15.51. Average D.M.F. teeth were 4.49${\pm}$3.69. 3. The average number of decayed (D) teeth were 2.09${\pm}$2.16. 4.30% of the present decayed teeth was secondary decay, and 2.44% of the decayed teeth was indicated for extraction. 4. The average number of missing(M) teeth were 0.32${\pm}$0.79. It included 8.56% of root fragements. 5. Average number of filled(F) teeth were 2.09${\pm}$3.17. F-ratio of this group was 46.45%. The analysis revealed 50.88% of amalgam alloy, 31.41% of gold inlays, and 1.20%, the least among the filling materials, silicate cement or composite resin. 6. While the prosthodontic treatment, such as crown and bridge has reduced than that of 10 years ago, the fillings and inlays as the conservative means has increased.

• The Journal of the Korean dental association
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• v.19 no.1 s.140
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• pp.40-44
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• 1981

This study is proposed to analyze statistically the causes of extraction of permanent teeth among outpatients who visited our dental department of Sung-Sim Hospital, Chung-Ang University from Jan. 29th 1979 to Nov. 30th 1980. the results are as follows. 1. The group of patients aged 25-34 had more number of extracted teeth than any other age group. 2. It was found that woman's (0.13) was more than man's(0.9) in average number of extracted teeth per patient. 3. In analyzing the causes of extraction, it was identified as caries 37.5%, periodontal diseases 27.2%, wisdom teeth 17.6%, for orthodontic treatment and impacted supernumerary teeth and others 8.0% trauma and fracture 4.2%. 4. The primary cause of extraction was found to be changed from caries to periodontal diseases according to the increase of age. 5. The number of teeth that were extracted by trauma was found that man's (38) was more than twice as much as woman's (17) and the group of patients aged 35-44 had the most number of all age groups.

• The Korean Journal of Health Service Management
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• v.10 no.3
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• pp.123-133
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• 2016

Objectives : This study analyzed the effect of health-related characteristics of middle-aged and elderly people on the number of existing permanent teeth by considering each age group through the improvement of health-related characteristics. This study contributes by offering fundamental information on the prevention of dental diseases and on developing an education program that can be used by dental health businesses to improve dental health. Methods : This study used primitive data of the sixth term of the first year and the second year and selected a total of 4,393 people as the final research subject. In order to determine the factors that influence the number of existing natural teeth, confounding factors were considered, and regression analysis using general linear models was done. Results : According to the results of this research, the middle-aged and elderly groups have more existing permanent teeth in the following three cases: 1. Talking is comfortable when daily brushing frequency is 3 times or more. 2. Self-recognition of dental health condition is good. 3. Number of dental caries present in permanent teeth is low. Conclusions : For a and medical system, a dental health care system that takes into consideration the lifespans of people must be legislated and implemented.

• Journal of dental hygiene science
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• v.11 no.3
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• pp.181-187
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• 2011

This study conducted oral examinations and individual interviews on migrant multi-cultural family women in Daegu and measured their socio-demographic characters, oral health conditions and OHIP-14 in an aim to investigate the relevance between the oral health of migrant multi-cultural family women living in some big cities and their quality of life. Based on data finally collected from 189 women, the t-test, ANOVA and binary logistic regression analysis were conducted and the conclusions are as follows: The average number of decayed teeth was 2.23, loss teeth was 1.48, and treated teeth was 5.58. Women from the Philippines had more number of loss teeth than those from other countries, and women from China relatively had a small number of filled permanent teeth. The quality of life related to oral health was found to be poor in proportion to the number of loss teeth. A comparison of life quality related to oral health depending on loss teeth showed that life quality related to oral health was lowest in the areas of mental discomfort, physical ability decrease, mental ability decrease, social ability decrease and social disadvantage. Life quality related to oral health was found to be low in proportion to the number of permanent teeth with decay experience and poor monthly household income, which shows that the number of permanent teeth with decay experience and monthly income are mostly related to life quality related to oral health. As migrant multi-cultural family women's life quality related to oral health is low in proportion to the number of loss teeth and decayed teeth, it needs to develop a program to improve their oral healthrelated life quality and conduct follow-up research to verify its effect.

• Journal of Korean society of Dental Hygiene
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• v.15 no.3
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• pp.417-424
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• 2015

Objectives: The purpose of the study is to investigate the relationship between oral health conditions and their subjective oral health perception in the elderly in Gimcheon. Methods: The study subjects were 214 elderly aged over 65 years old in Gimcheon. The study was carried out by direct interview method of from February 20 to 24, 2014. The oral examination was performed by the dentist base on the World Health Organization criteria including direct examination and observation. The questionnaire consisted of sex, type of family, use of medical services, and oral health behavior, The independent variable included three questions of the general characteristics of the subjects, two questions of use of medical services, and two questions of oral health behavior. The subjective oral health perception was composed of heathy and unhealthy. The objective oral health condition was evaluated by number of residual teeth, FT index, MT index, and DMFT index. Results: In the elderly, the number of residual tooth was $8.89{\pm}9.72$ and the number of decayed teeth was $0.03{\pm}0.20$. The numbers of missing teeth and filled teeth were $19.26{\pm}9.65$ and $0.28{\pm}1.01$, respectively. The DMFT index was $19.57{\pm}9.28$. In relation to the subjective oral health perception, 76.6% answered 'good' and 23.4% answered 'bad'. The subjective oral health perception showed a weak quantitative linear relationship of r=0.235 with the number of residual tooth. the subjective oral health perception showed a weak negative linear relationship(p<0.01) of r=-0.225 with the number of missing teeth and r=-0.217 with DMFT(number of decayed missing and filled teeth) index.

• 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.

• The korean journal of orthodontics
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• v.23 no.3 s.42
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• pp.319-326
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• 1993

The purpose of this study was to evaluate the frequency of congenital missing teeth and supernumerary teeth in cleft patients. The subjects were divided into bilateral cleft lip and palate(BCLP), unilateral cleft lip and palate(UCLP) and cleft palate alone(CP alone) groups. 97 cleft patients(BCLP 15, UCLP 70, CP alone 12) between 6-20 years old were evaluated. Panorama film, Orthodontic chart and initial intraoral photogram were employed for this research. The obtained results were as follows. 1. The incidence of congenital missing teeth in total cleft samples was $57.7\%$, and the incidence of supernumerary teeth was $26.8\%$. Each incidence was higher than non-cleft. 2. The incidence of congenital missing teeth was the highest in BCLP and the lowest in CP alone. 3. The number of congenital missing teeth per perso was usually one, and the frequency was higher in the maxillary lateral incisors$(67.8\%)$, and maxillary second premolar$(14.9\%)$ than other teeth. 4. Most of tooth number anomalies in cleft patients were found in maxilla, especially adjacent region to the cleft site.

• Journal of Korean society of Dental Hygiene
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• v.18 no.2
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• pp.205-215
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• 2018

Objectives: The purpose of the study is to investigate the relationship between the number of remaining teeth and bone health status among adults over 65 years old. Methods: The study subjects were 1,843 adults over 65 years old drawn from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2008-2010. Oral health status included the number of remaining teeth, and prosthetic appliance status. Bone health statuses were assessed using dual-energy X-ray absorptiometry (DEXA). Bone health statuses were classified into normal (T-score ${\geq}-1.0$), osteopenia (-2.5 < T-score < -1.0), and osteoporosis (T-score ${\leq}-2.5$). Complex samples chi-square test was used to estimate the relationship between the number of remaining teeth and bone health status, and related factors included in the model were analyzed with the complex samples logistic regression analysis. Results: Using the multinomial logistic regression analytic method, the elderly having 20 or more remaining teeth and those having less than 20 remaining teeth with prosthesis were compared. The latter group had 1.89 times higher rate of being diagnosed as having osteoporosis. Conclusions: This study suggests that oral health is an important factor for geriatric osteoporosis. Therefore, in order to prevent fractures due to osteoporosis and osteoporosis in old age, it is necessary to be aware of the relationship between oral health and osteoporosis, and oral health should be considered when preparing preventive management strategies.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.629-637
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• 2021

Objectives: The purpose of this study was to investigate the degree of activity restriction and the number of remaining teeth of the elderly and to analyze the correlation. Methods: Statistical analysis of the collected data was analyzed using the SPSS window program 25.0 version (IBM) using a composite sample for the analysis of the 7th National Health and Nutrition Survey data, and a composite sample multiple logistic regression analysis was performed to confirm the effect of activity restrictions on the number of remaining teeth. Results: As a result of analyzing the effect of activity restriction on the number of remaining teeth, in the model that analyzed only activity restriction variables, the risk ratio of less than 20 remaining teeth was 1.61 times higher and the age-adjusted model, the risk ratio of less than 20 remaining teeth was 1.46 times higher (p<0.001). In the model that corrected all variables, the results were not statistically significant. Conclusions: In this study, the relationship between activity restriction and the number of remaining teeth could be confirmed, and in subsequent studies, more in-depth studies are considered to be needed using sub-variables that specifically reflect the reasons for activity restriction.

• Journal of Oral Medicine and Pain
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• v.16 no.1
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• pp.33-72
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• 1991

The purpose of this study was to investigate the stress distribution and the displacement in the temporomandibular joints following the teeth loss patterns. The three dimensional finite element method was used for a mathematical model. The finite element model was composed of 1,632 elements and 2,411 nodes in the mandible with articular disc and mandibular fossa of the temporal bone. The masseter, the temporal and the internal pterygoid muscle forces were applied at each insertion site, bisecting point of gonion and antegonion, tip of the coronoid process, and gonion at the ration of 2:2:1 respectively. The directions of muscles force were obtained from frontal and lateral cephalometric tracings using bony landmarks of the skull. The results were as follows : 1. In control model, the minimum principal stresses were concentrated on the region of anterosuperior part of the condyle head and articular disc, and maximum principal stresses on the anterior part of the condyle head and posterolateral part of the articular disc. 2. In case of unilateral teeth loss, the greater principal stress appeared at the teeth loss side and the principal stresses increased at the teeth loss side as the number of the posterior teeth loss went up. 3. In case of bilateral teeth loss, the principal stresses were greater than those of the control model and as the number of the posterior teeth loss increased, the grater principal stresses on the temporomandibular joints appeared at the both side. 4. When the posterior teeth existed bilateral, the principal stress patterns were similar to those of the control model. 5. The displacement ws directed mainly upward and backward in the upper part of the temporomandibular joints and upward and forward in the largest part of the condyle head. The displacement increased as the number of the posterior teeth loss went up.