Tooth caries classification with quantitative light-induced fluorescence (QLF) images using convolutional neural network for permanent teeth in vivo.

BACKGROUND: Owing to the remarkable advancements of artificial intelligence (AI) applications, AI-based detection of dental caries is continuously improving. We evaluated the efficacy of the detection of dental caries with quantitative light-induced fluorescence (QLF) images using a convolutional neural network (CNN) model. METHODS: Overall, 2814 QLF intraoral images were obtained from 606 participants at a dental clinic using Qraypen C® (QC, AIOBIO, Seoul, Republic of Korea) from October 2020 to October 2022. These images included all the types of permanent teeth of which surfaces were smooth or occlusal. Dataset were randomly assigned to the training (56.0%), validation (14.0%), and test (30.0%) subsets of the dataset for caries classification. Moreover, masked images for teeth area were manually prepared to evaluate the segmentation efficacy. To compare diagnostic performance for caries classification according to the types of teeth, the dataset was further classified into the premolar (1,143 images) and molar (1,441 images) groups. As the CNN model, Xception was applied. RESULTS: Using the original QLF images, the performance of the classification algorithm was relatively good showing 83.2% of accuracy, 85.6% of precision, and 86.9% of sensitivity. After applying the segmentation process for the tooth area, all the performance indics including 85.6% of accuracy, 88.9% of precision, and 86.9% of sensitivity were improved. However, the performance indices of each type of teeth (both premolar and molar) were similar to those for all teeth. CONCLUSION: The application of AI to QLF images for caries classification demonstrated a good performance regardless of teeth type among posterior teeth. Additionally, tooth area segmentation through background elimination from QLF images exhibited a better performance.

Effects of professional toothbrushing among patients with gingivitis.

OBJECTIVES: This study aimed to evaluate the biological and clinical effect of professional toothbrushing on the periodontal health of patients with gingivitis. METHODS: We enrolled 21 university students with gingivitis in Jinju City in this study between April 24 and October 28, 2014. A dental hygienist performed a professional toothbrushing routine on the participants twice, once at baseline and after 3 months. Oral examinations were performed at baseline, 3, and 6 months to assess the periodontal health. The patient hygiene performance index, gingival bleeding rate, periodontal pocket depth, amount of gingival sulcus fluid, and number of bacterial colonies in the gingival sulcus (CFU/mL) were evaluated during the oral examination. RESULTS: The patient hygiene performance index, gingival bleeding rate, pocket depth, amount of gingival sulcus fluid, and CFU/mL within the gingival sulcus significantly decreased after professional toothbrushing (p < 0.05), indicating an improvement in the periodontal health. The patient hygiene performance index, gingival bleeding rate, pocket depth, amount of gingival sulcus fluid, and CFU/mL within the gingival sulcus decreased more among those whose pocket depth was 4-5 mm than among those whose PD was ≤3 mm (p < 0.05). CONCLUSIONS: Professional toothbrushing improved the periodontal health in patients with gingivitis in respect of both biological and clinical results.

Caries detection with tooth surface segmentation on intraoral photographic images using deep learning.

BACKGROUND: Intraoral photographic images are helpful in the clinical diagnosis of caries. Moreover, the application of artificial intelligence to these images has been attempted consistently. This study aimed to evaluate a deep learning algorithm for caries detection through the segmentation of the tooth surface using these images. METHODS: In this prospective study, 2348 in-house intraoral photographic images were collected from 445 participants using a professional intraoral camera at a dental clinic in a university medical centre from October 2020 to December 2021. Images were randomly assigned to training (1638), validation (410), and test (300) datasets. For image segmentation of the tooth surface, classification, and localisation of caries, convolutional neural networks (CNN), namely U-Net, ResNet-18, and Faster R-CNN, were applied. RESULTS: For the classification algorithm for caries images, the accuracy and area under the receiver operating characteristic curve were improved to 0.813 and 0.837 from 0.758 to 0.731, respectively, through segmentation of the tooth surface using CNN. Localisation algorithm for carious lesions after segmentation of the tooth area also showed improved performance. For example, sensitivity and average precision improved from 0.890 to 0.889 to 0.865 and 0.868, respectively. CONCLUSION: The deep learning model with segmentation of the tooth surface is promising for caries detection on photographic images from an intraoral camera. This may be an aided diagnostic method for caries with the advantages of being time and cost-saving.

Costunolide Induces Apoptosis via the Reactive Oxygen Species and Protein Kinase B Pathway in Oral Cancer Cells.

Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

Subjective chewing ability and health-related quality of life among the elderly.

OBJECTIVE: Chewing ability may reflect the overall oral health, which affects the general health of the elderly. Therefore, we assessed the association between subjective chewing ability and health-related quality of life (HRQOL) among the elderly. METHODS: We analysed the data of 3034 elderly people aged ≥65 years from the Korean National Health and Nutrition Examination Survey that was conducted by the Korean government from 2013 to 2015 (KNHANES-VI). Subjective chewing ability was evaluated using a questionnaire, and HRQOL was assessed using EuroQol 5-dimension (EQ-5D) instrument by trained examiners. Covariates, such as socio-demographic, oral health-related and general health-related variables, were investigated. RESULTS: Logistic regression analysis showed that chewing ability was significantly associated with HRQOL in both crude and adjusted model for covariates such as age, gender, economic activity, residence, education, smoking, alcohol, hypertension, diabetes, remaining teeth, denture, CPI, tooth brushing and oral hygiene (crude OR, 2.67; 95% CI, 2.23-3.20) (adjusted OR, 2.36; 95% CI, 1.95-2.86). Chewing ability was also significantly associated with most dimensions of EQ-5D, such as motor ability, self-care, daily activities, pain and discomfort, and anxiety and depression (P < 0.05). CONCLUSION: Chewing ability was significantly associated with HRQOL, suggesting that elderly people with low chewing ability are more likely to have poor health-related quality of life.

Lead exposure may affect gingival health in children.

BACKGROUND: Several studies have reported the harmful effects of lead poisoning. However, the relationship between lead exposure and oral health of children has not been well defined. The aim of this study was to investigate the relationship between blood lead level (BLL) and oral health status of children. METHODS: A total of 351 children (aged 7-15 years) were recruited from the pilot data of the Korean Environmental Health Survey in Children and Adolescents, which was designed to examine environmental exposure and children's health status in South Korea. Blood samples were taken to determine BLLs and oral examinations were performed to assess oral health parameters, including community periodontal index (CPI), gingival index (GI), and plaque index (PI). Information regarding socioeconomic status, oral hygiene behavior, and dietary habits was collected from parents and guardians. RESULTS: The participants were divided equally into four quartiles, with quartile I comprised of children with the lowest BLLs. There were significant differences for PI (p < 0.05) among the quartile groups. Using logistic regression models, we found a significant relationship between BLL and oral health parameters. The crude odds ratios for CPI, GI, and PI in the third quartile were 5.24 (95% CI: 1.48-18.56), 4.35 (95% CI: 1.36-13.9), and 4.17 (95% CI: 1.50-11.54), respectively, while the age and gender-adjusted odds ratios were 7.66 (95% CI: 1.84-31.91), 6.80 (95% CI: 1.80-25.68), and 3.41 (95% CI: 1.12-10.40), respectively. After adjustments for age, gender, parent education level, and frequency of tooth brushing, the adjusted odds ratios were 7.21 (95% CI: 1.72-30.19), 6.13 (95% CI: 1.62-23.19), and 3.37 (95% CI: 1.10-10.34), respectively. CONCLUSIONS: A high BLL might be associated with oral health problems in children, including plaque deposition and gingival diseases.

Orotidine-Containing RNA: Implications for the Hierarchical Selection (Systems Chemistry Emergence) of RNA.

The prebiotic synthesis of canonical nucleobases from HCN is a cornerstone for the RNA world hypothesis. However, their role in the primordial pathways to RNA is still debated. The very same process starting from HCN also gives rise to orotic acid, which (via orotidine) plays a crucial role in extant biology in the de novo synthesis of uridine and cytidine, the informational base-pairs in RNA. However, orotidine itself is absent in RNA. Given the prebiotic and biological relevance of orotic acid vis-à-vis uracil, we investigated orotidine-containing RNA oligonucleotides and show that they have severely compromised base-pairing properties. While not unexpected, these results suggest that the emergence of extant RNA cannot just be a consequence of the plausible prebiotic formation of its chemical constituents/building blocks. In combination with other investigations on alternative prebiotic nucleobases, sugars, and linkers, these findings imply that the selection of the components of extant RNA occurred at a higher hierarchical level of an oligomer/polymer based on its functional properties-pointing to a systems chemistry emergence of RNA from a library of precursors.

Hydrogen-Bonding Complexes of 5-Azauracil and Uracil Derivatives in Organic Medium.

Uracil derivatives form strong complexes with complementary 2,4-diaminotriazine and adenine compounds, whereas derivatives of 5-azauracil (2,4-dioxotriazine) are known to form weak complexes in aqueous medium. However, herein we report that in organic medium (CDCl3), the 5-azauracil moiety forms hydrogen-bond-mediated complexes with complementary 2,4-diaminotriazine and adenine compounds, with strengths comparable to those formed by uracil compounds. Such dichotomous base-pairing behavior of the 5-azauracil moiety, in organic versus aqueous media, is found to be consistent with the ionization of the 5-azauracil moiety in aqueous medium leading to competitive interference from water molecules (via solvation), which is absent (lack of such ionization and solvent interference) in organic medium. This discriminating role of solvent (e.g., water) could have been an important factor in the selection of molecules, based on their physicochemical properties, and subsequently in the emergence of potential primordial informational oligomers that would have played a role in the origins of life.

Metabolic syndrome parameters in adolescents may be determinants for the future periodontal diseases.

AIM: The prevalence of metabolic syndrome (MetS) increases even in adolescents. The evidence that MetS is associated with the periodontal diseases in adolescents has been understudied. Therefore, our aim was to assess the association between MetS parameters and gingivitis in adolescents. MATERIAL AND METHODS: A total of 941 participants (590 boys, 351 girls), aged 12-18 years was selected from the Fourth Korea National Health and Nutrition Examination Survey, a cross-sectional and nationally representative survey, which had had information on waist circumference, blood pressure, serum triglyceride, high-density lipoprotein (HDL) cholesterol, and the fasting blood sugar and community periodontal Index (CPI). RESULTS: The number of positive parameters of MetS showed significant positive correlation with gingivitis; adjusted and crude ORs with one positive parameters of MetS were 1.92 (95% CI: 1.21-3.04) and 1.88(95% CI: 1.28-2.76), respectively. And adjusted OR with three or more positive parameters of MetS was 3.29 (95% CI: 1.24-8.71). Among five parameters of MetS, Low HDL-cholesterol showed significant association with gingivitis (crude OR 2.12, 95% CI 1.20-3.73; adjusted OR 1.96, 95% CI 1.24-3.12). CONCLUSIONS: Having more positive parameters of MetS and low HDL-cholesterol parameter had an independent relationship with the prevalence of gingivitis, which may be determinants for the future periodontal diseases even in adolescents.

Relationship between bone mineral density, its associated physiological factors, and tooth loss in postmenopausal Korean women.

BACKGROUND: Previous studies have proposed a relationship between bone mineral density (BMD) and oral health. However, the relationship between BMD and tooth loss in female individuals is not yet well understood. Therefore, the aim of this study was to assess the association between BMD, including its related physiological factors, and tooth loss among postmenopausal women in Korea. METHODS: A total of 3,992 postmenopausal women aged 50 years or above were selected from the Fourth and Fifth Korea National Health and Nutrition Examination Surveys, which were cross-sectional in design and conducted from 2008 to 2011. The participants' BMD and number of teeth were assessed by radiologists and dentists. Socioeconomic characteristics and female-related physiological factors, including menarche age, duration of menopause, number of pregnancies, age at first child's birth, and duration of oral contraceptive or female hormone use, were surveyed. RESULTS: Participants who had lower BMD had significantly fewer teeth (p < 0.001). Female-related physiological factors, including the duration of menopause, number of pregnancies, age at first child's birth, duration of oral contraceptive or female hormone use, and calcium intake level, showed a significant relationship with the number of teeth. Using multiple regression analysis, BMD, duration of menopause, age at first child's birth, and duration of female hormone use significantly influenced the number of teeth. CONCLUSIONS: BMD and its related physiological factors in female individuals showed a significant relationship with the number of teeth in postmenopausal Korean women, implicating osteoporosis as a risk factor for tooth loss in postmenopausal women.

Burnout and its related factors in Korean dentists.

OBJECTIVES: Dentistry has been identified as one of the most stressful work environments. Knowledge of modifiable work-environment factors related to job stress could lead to a strategy and policy to provide a better work environment for dentists. The aims of this study were to examine the degree and distribution of burnout and to determine the factors associated with burnout subscale of Korean dentists. METHODS: A cross-sectional survey of Korean dentists was conducted using a custom-designed and validated questionnaire that incorporated the Maslach Burnout Inventory Human Services Survey (MBI-HSS) as well as questions regarding sociodemographic and job-related characteristics. A random sample of 1,000 dentists was selected from 13,207 registered dentists in the Korean Dental Association. The MBI-HSS scores were summarised in the three dimensions of emotional exhaustion, depersonalisation, and personal sense of accomplishment. Bivariate and multivariate analyses were conducted to assess the prevalence of burnout and its related factors. RESULTS: The adjusted response rate was 45.9% (444/967). In the subscales of burnout, 41.2%, 55.9%, and 41.4% of respondents scored highly in emotional exhaustion and depersonalisation and poorly for personal sense of accomplishment, respectively. High burnout seems to be more likely to occur in association with some of the sociodemographic and job-related characteristics, especially younger age, male gender, without occupational calling, and unwilling to reselect a dentistry as a job. CONCLUSIONS: This study suggests that burnout is a common problem in Korean dentists and that occupational calling and willing to reselect a dentistry as a job are important factors for managing burnout.

Association between diabetes-related factors and clinical periodontal parameters in type-2 diabetes mellitus.

BACKGROUND: Evidence consistently shows that diabetes is a risk factor for increased prevalence of gingivitis and periodontitis. But there is a controversy about the relationship between diabetes related factors and periodontal health. The aim of the present study is to explore the relationship between diabetes related factors such as glycosylated hemoglobin, fasting blood glucose, duration of diabetes and compliance to diabetes self management and periodontal health status. METHODS: Periodontal health of 125 participants with type-2 diabetes mellitus was measured by the number of missing teeth, community periodontal index (CPI), Russell's periodontal index and papillary bleeding index. Information on sociodemographic factors, oral hygiene behavior, duration and compliance to self management of diabetes, levels of glycosylated hemoglobin(HbA1c) and fasting blood glucose(FBG) were collected by interview and hospital medical records. Statistically, independent t-test, an analysis of variance (ANOVA), chi-squared test and multiple regression analyses were used to assess the association between diabetes-related factors and periodontal health. RESULTS: Periodontal parameters including the number of missing teeth and papillary bleeding index were significantly influenced by duration of diabetes, FBG and compliance to self management of diabetes. CPI was significantly influenced by duration of diabetes, FBG and HbA1C. And Russell's periodontal index was significantly influenced by duration of diabetes, FBG, HbA1C and compliance to self management of diabetes. Results of multiple linear regression analysis showed that the duration of diabetes showed significant positive correlation with all of the periodontal health parameters, except for missing teeth. HbA1c was correlated with Russell's periodontal and papillary bleeding index. FBG and compliance to self management of diabetes were correlated with missing teeth and papillary bleeding index respectively. CONCLUSIONS: Diabetes-related factors such as duration of diabetes, FBG, HbA1c and compliance to self management of diabetes were significantly correlated with periodontal health among individuals with type-2 diabetes.

Three-dimensional printing of temporary crowns with polylactic acid polymer using the fused deposition modeling technique: a case series.

With recent developments in digital dentistry, research on techniques and materials for three-dimensional (3D) printing is actively underway. We report the clinical applications and outcomes of 3D printing of temporary crowns fabricated with polylactic acid (PLA) using a fused deposition modeling (FDM) printer. Five participants were recruited from among patients scheduled to be treated with a single full-coverage crown at a dental clinic in a university medical center from June to August 2022. We used 3D-printed crowns fabricated with PLA using an FDM printer as temporary crowns and were assessed for discomfort, fracture, and dislodging. The 3D-printed temporary crowns were maintained without fracture, dislodging, or discomfort until the permanent prosthesis was ready. The average time required for printing the temporary crowns was approximately 7 minutes. The 3D printing of temporary crowns with PLA using an FDM printer is a convenient process for dentists. However, these crowns have some limitations, such as rough surface texture and translucency; therefore, the 3D printing process should be improved to produce better prostheses.

Association between periodontal disease and hypertriglyceridemia: Propensity score matching analysis using the 7th Korea National Health and Nutrition Examination Survey.

The prevalence of periodontitis and dyslipidemia continues to increase, and several studies have reported an association between the 2. Therefore, we assessed the relationship between periodontitis and hypertriglyceridemia using propensity score matching to efficiently address confounding factors, as well as complex sample analysis with data from Korea National Health and Nutrition Examination Survey VII (2016-2018). To match the 1:1 ratio between the groups with and without periodontitis, the propensity scores of covariates, such as age, sex, education, income, smoking, drinking, obesity, and diabetes mellitus, were calculated using logistic regression. Both results of logistic regression analysis using complex sample design for whole and matched sample after propensity score matching demonstrated a significant association between hypertriglyceridemia and periodontitis, of which the adjusted odds ratio was 1.28 (95% confidence interval = 1.10-1.50) and 1.29 (95% confidence interval = 1.09-1.52), respectively. Our findings suggest that dental healthcare workers can help raise awareness among patients with periodontitis regarding the association between periodontitis and hypertriglyceridemia, which may help them manage the condition and receive treatment.

Association between dental amalgam restoration and urine mercury concentrations among young women: a cross-sectional study.

BACKGROUND: The association between dental amalgam fillings and urine mercury concentrations was investigated in this study to assess the health risks associated with dental amalgams. METHODS: This cross-sectional study included 99 women in their 20s who visited the dental clinic in Daegu, Korea. The 99 participants were composed of 68 subjects who had dental amalgam fillings (exposure group) and 31 subjects who did not have dental amalgam fillings (nonexposure group). Oral examinations were conducted by a single dental hygienist, sociodemographic features were investigated as confounding variables, and urine mercury concentrations were measured using an automatic mercury analyzer. RESULTS: The mean±standard deviation of the urine mercury concentrations of the exposure and nonexposure groups were 1.50±1.78 µg/g creatinine and 0.53±0.63 µg/g creatinine, respectively. The exposure group showed significantly higher levels than the nonexposure group (p<0.01). The urine mercury concentration significantly increased with an increase in the number of teeth filled with amalgam, cavity surfaces involved, and number of defective amalgam fillings, and according to the latest exposure time (p<0.001). In the multiple regression analysis of amalgam-related factors and urine mercury concentrations after correction for confounding factors, the urine mercury concentration in the group with six or more amalgam-filled teeth, 11 or more cavity surfaces, and two or more defective amalgams was significantly higher than that in the nonexposure group (p<0.001). CONCLUSION: According to this study, exposure to dental amalgams was confirmed to significantly affect urine mercury concentrations.

Effects of Hydrogen-rich Water on Cariogenic Bacteria.

Context: Some kinds of electrolysed water have been reported to exhibit antioxidant and bactericidal activity. However, studies on the effect of electrolysed hydrogen-rich water (EHW) with a neutral pH on cariogenic bacteria are limited. Aim: This study aimed to evaluate the feasibility of using EHW as a mouthwash by examining its various effects on cariogenic bacteria. Materials and Methods: To test the bactericidal and anti-biofilm formation effects of EHW on Streptococcus mutans and Streptococcus sobrinus, bacterial growth curves, colony-forming unit (CFU) counts, and crystal violet staining of biofilms were examined after exposing the bacterial pellets to EHW or tap water as a control for one minute. In addition, the expressions of glucosyltransferase and glucan-binding proteins encoding genes were examined using real-time PCR. Results: Bacterial growth and biofilm formation were inhibited, and the number of CFUs was significantly reduced in the EHW group compared to the control group. The expression of genes encoding glucosyltransferases (gtfB, gtfC, and gtfI) and glucan-binding proteins (gbpC and dblB) were also decreased in the EHW group compared to the control. Conclusions: Exposing cariogenic bacteria to EHW at neutral pH for one minute can effectively inhibit bacterial growth and biofilm formation in vitro, suggesting that EHW is a promising mouthwash.

Silibinin induces oral cancer cell apoptosis and reactive oxygen species generation by activating the JNK/c-Jun pathway.

Background: Oral cancer is one of the most prevalent malignant tumors worldwide. Silibinin has been reported to exert therapeutic effects in various cancer models. However, its mechanism of action in oral cancer remains unclear. We aimed to examine the molecular processes underlying the effects of silibinin in oral cancer in vitro and in vivo as well as its potential anticancer effects. Next, we investigated the molecular processes underlying both in vitro and in vivo outcomes of silibinin treatment on oral cancer. Methods: To investigate the effects of silibinin on the growth of oral cancer cells, cell proliferation and anchorage-independent colony formation tests were conducted on YD10B and Ca9-22 oral cancer cells. The effects of silibinin on the migration and invasion of oral cancer cells were evaluated using transwell assays. Flow cytometry was used to examine apoptosis, cell cycle distribution, and accumulation of reactive oxygen species (ROS). The molecular mechanism underlying the anticancer effects of silibinin was explored using immunoblotting. The in vivo effects of silibinin were evaluated using a Ca9-22 xenograft mouse model. Results: Silibinin effectively suppressed YD10B and Ca9-22 cell proliferation and colony formation in a dose-dependent manner. Moreover, it induced cell cycle arrest in the G0/G1 phase, apoptosis, and ROS generation in these cells. Furthermore, silibinin inhibited the migration and invasion abilities of YD10B and Ca9-22 cells by regulating the expression of proteins involved in the epithelial-mesenchymal transition. Western blotting revealed that silibinin downregulated SOD1 and SOD2 and triggered the JNK/c-Jun pathway in oral cancer cells. Silibinin significantly inhibited xenograft tumor growth in nude mice, with no obvious toxicity. Conclusions: Silibinin considerably reduced the development of oral cancer cells by inducing apoptosis, G0/G1 arrest, ROS generation, and activation of the JNK/c-Jun pathway. Importantly, silibinin effectively suppressed xenograft tumor growth in nude mice. Our findings indicate that silibinin may be a promising option for the prevention or treatment of oral cancer.

Association between periodontal disease and diabetes using propensity score matching: The seventh Korea National Health and Nutrition Examination Survey.

The association between periodontitis and diabetes have been assessed by many cross-sectional studies, in which controlling confounding factors is important. Propensity score matching (PSM) may help address this issue. Therefore, we evaluated this relationship in a (PSM) analysis of individuals representing the general Korean population. Periodontitis was significantly associated with diabetes before PSM (odds ratio [OR] = 1.53; 95 % confidence interval (CI) = 1.31-1.80) and after PSM (OR = 1.52; 95 % CI = 1.28-1.80). This study showed the association between periodontitis and diabetes using PSM, suggesting that periodontitis may be positively related with diabetes. We included 9508 adults who were aged ≥ 19 years from the Korea National Health and Nutrition Examination Survey VII (2016-2018) and performed logistic regression analyses before and after PSM. The PSM was based on periodontal disease (yes or no) using a 1:1 match ratio and included 5858 individuals (2929 per group). Confounding variables, such as age, sex, marital status, occupation, education, income, smoking and drinking habits, obesity, hypertension, hypercholesterolemia, and hypertriglyceridemia, were matched and adjusted in the logistic regression analysis.

Incidence of edentulism among older adults using the Korean National Health Insurance Service database, 2013-2018.

OBJECTIVES: Population aging is rapidly accelerating worldwide. Oral diseases related to aging are also on the rise. This study examined trends in the incidence of edentulism among the older Korean population using data from the Korean National Health Insurance Service (KNHIS). METHODS: Data on older adults, aged ≥75 years of age, were obtained from the KNHIS for the period 2013-2018. Edentulism was defined as a treatment history of complete dentures in the KNHIS database. The exclusion criteria consisted of both disease codes and treatment codes related to conservative dental treatment, including periodontal and extraction treatment afterward. Crude incidence rates (CIRs) and age-standardized incidence rates (AIRs) with 95% confidence intervals were calculated and reported per 100,000 person-years by the direct method. Trends were tested by Cochrane Armitage models. RESULTS: Statistically significant increasing trends in both CIRs and AIRs were found among the older Korean population registered in the KNHIS (CIRs, 707.92 to 895.92; AIRs, 705.11 to 889.68; p<0.01). The incidence tended to increase in both genders (p<0.01). Both CIRs and AIRs in specific regions also showed slight but significant annual increases except for Jeju Island (p<0.01 or <0.05). The incidence showed increasing trends (p<0.01) in all income quintiles apart from the highest quintile. The edentulism incidence was highest in the lowest income group (the first quintile). CONCLUSIONS: Our data showed that the incidence of edentulism among the elderly showed an increasing trend from 2013 to 2018. This result provides a basis for future epidemiological studies on the incidence of edentulism in the older Korean population.

Influence of Chewing Ability on Elderly Adults' Cognitive Functioning: The Mediating Effects of the Ability to Perform Daily Life Activities and Nutritional Status.

Chewing ability is also related to activities of daily living (ADLs) and nutritional status; however, these associations have not been firmly established. We examined chewing ability as a predictor variable and explored its relationship with cognitive functioning as mediated by ADLs and nutritional status data were collected by face-to-face interviews. Patients were receiving home healthcare service in Mun-gyeong city, Gyung-buk, Korea. Participants comprised 295 patients aged 81.35 ± 6.70 years. Structural equation modeling (SEM) was performed using AMOS 18.0 (SPSS Inc., Chicago, IL, USA). The model fit was based on absolute fit index and incremental fit index. Data were collected to assess cognitive functioning (using the Korean version of the Mini-Mental Status Examination for dementia screening (MMSE-DS)), ADL, a mini-nutritional assessment (MNA) questionnaire, and a chewing ability test. Participants with better chewing ability had significantly better cognitive functioning, ADLs, and nutritional status (p < 0.001). Chewing ability directly affected cognitive functioning and indirectly affected how ADLs and MNA affected MMSE-DS. Chewing ability is an important factor influencing the cognitive functioning of elderly adults in Korea, both directly and indirectly through mediating variables such as nutritional status and ADLs. Efforts to help older adults maintain their chewing ability are necessary for preventing cognitive impairment.