Impact of the Coronavirus Disease 2019 Pandemic on Dental Visits in Japan.

PURPOSE: This study aimed to clarify the impact of the coronavirus disease 2019 (COVID-19) pandemic on individual dental-visit behaviour and examine the difference between elderly and other individuals regarding the impact on dental visits. MATERIALS AND METHODS: An interrupted time-series analysis was performed to examine the change in data from the national database before and after the first declaration of a state of emergency. RESULTS: The number of patients visiting a dental clinic (NPVDC), number of dental treatment days (NDTD) and dental expenses (DE) during the first declaration of a state of emergency decreased by 22.1%, 17.9%, and 12.5% in the group under 64 years of age and 26.1%, 26.3%, and 20.1% in the group over 65 years of age, respectively, compared with those in the same month of the previous year. Between March and June 2020, the monthly NPVDC and NDTD were significantly reduced (p < 0.001, p = 0.013) in those over 65 years of age. The DE did not change statistically significantly in either the under 64 group or the over 65 group. There was no statistically significant change in the slope of the regression line in the NPVDC, NDTD, and DE before and after the first state-of-emergency declaration. CONCLUSION: The first state of emergency greatly reduced the NPVDC, NDTD, and DE compared to those in the previous year. In people aged over 65 years, it might still be unresolved 2 years after the postponement of dental treatment owing to the first declaration of a state of emergency.

Discordance between hyposalivation and xerostomia among community-dwelling older adults in Japan.

Individuals with an objective decrease in salivary flow (objective dry mouth) may not be aware of subjective dry mouth (xerostomia). However, no clear evidence exists to explain the discordance between subjective and objective dry mouth. Therefore, this cross-sectional study aimed to assess the prevalence of xerostomia and decreased salivary flow among community-dwelling elderly adults. In addition, this study assessed several potential demographic and health status determinants of the discrepancy between xerostomia and reduced salivary flow. The 215 participants in this study were community-dwelling older people aged 70 years and above who underwent dental health examinations between January-February 2019. Symptoms of xerostomia were collected in the form of a questionnaire. The unstimulated salivary flow rate (USFR) was measured by a dentist using visual inspection. The stimulated salivary flow rate (SSFR) was measured using the Saxon test. We identified 19.1% of participants as having mild-severe USFR decline with xerostomia and 19.1% as having mild-severe USFR decline without xerostomia. Additionally, 26.0% of participants had low SSFR and xerostomia, and 40.0% had low SSFR without xerostomia. Except for the age trend, no factors could be associated with the discordance between USFR measurement and xerostomia. Furthermore, no significant factors were associated with the discordance between the SSFR and xerostomia. However, females were significantly associated (OR = 2.608, 95% CI = 1.174-5.791) with low SSFR and xerostomia, as compared to males. Age was a factor that was also significantly associated (OR = 1.105, 95% CI = 1.010-1.209) with low SSFR and xerostomia. Our findings indicate that approximately 20% of the participants had low USFR without xerostomia, and 40% had low SSFR without xerostomia. This study showed that age, sex, and the number of medications may not be factors in the discrepancy between the subjective feeling of dry mouth and reduced salivary flow.

Comparison of two alcohol hand rubbing techniques regarding hand surface coverage among hospital workers: a quasi-randomized controlled trial.

BACKGROUND: The adapted 6-step without interlock (A6Sw/oI) hand rub technique, commonly practiced in Japan, adds the "wrist" but omits the "interlock" step compared to the WHO 6-step technique (WHO6S). The first objective of this study was to assess the differences of the two techniques regarding surface coverage. The second objective was to analyze the coverage differences between hand sizes. METHODS: Hospital workers went under stratified quasi-randomization by glove size. The overall mean coverage, and the coverage of the sections of the hands were evaluated by fluorescent dye-based coverage assessment using a digital device with artificial intelligence technology. RESULTS: Total of 427 workers were randomly allocated to WHO6S (N = 215) or the A6Sw/oI (N = 212). The overall mean dorsum coverage by WHO6S and A6Sw/oI was 90.6% versus 88.4% (p < 0.01), and the percentage of the participants with insufficient coverage of the backs of the four fingers ranged from 0.0-7.4% versus 28.2-51.4% (p < 0.001). Dorsum coverage varied largely between hand size for both techniques, and significant differences were found between small and large hands. CONCLUSION: The WHO6S was superior to the locally adapted technique regarding hand surface coverage. Hand size should be considered when assessing coverage differences between procedures. No trial registrations or fundings.

[Relationship between the number of prescribed medications and oral dysfunction in elderly individuals].

Objective　Polypharmacy in elderly individuals may cause reduced flow of saliva and xerostomia. A dry mouth can lead to poor oral function; however, there are no reports on the relationship between polypharmacy and subjective or objective oral dysfunction. The purpose of this study was to clarify the relationship between the number of prescribed medications and subjective and objective oral dysfunction.Methods　The subjects of this study were 215 community-dwelling, elderly individuals, aged 75 years or older, who visited the dental clinic in the Chubu region for a dental health examination from January to February 2019. A medical interview was conducted to assess three items that were related to subjective oral function and record four measurements related to objective oral function. In addition, information was collected on the diseases being treated and prescribed medications. A subject with a decrease in any of the three subjective oral function categories was considered to have subjective oral dysfunction. Objective oral dysfunction was analyzed with respect to two types of oral dysfunction: a decrease in all four objective oral functions and a decrease in two or more of the four objective oral functions. Logistic regression analysis was performed to examine the relationship between subjective and objective oral dysfunction after adjustment for sex, age group, inveterate disease, and the number of prescribed medications.Results　Individuals who had eight or more prescribed medications had lower subjective oral function than those with seven or fewer medications (odds ratio, 95% confidence interval: 2.3, 1.0-5.1; P<0.05). Individuals with eight or more medications had lower scores in all four objective oral functions than those with seven or fewer medications (4.4 : 1.5-12.6, P<0.01). A decrease in two or more of the four objective oral functions was related to 10 or more prescribed medications (4.3 : 1.2-16.2, P<0.05).　In addition, taking eight or more prescribed medications was associated with a decrease in either subjective oral function or all four objective oral functions (8.1 : 2.1-30.8, P<0.01). A decrease in either subjective oral function or two or more objective oral functions was related to taking 10 or more prescribed medications (4.9 : 1.6-15.6, P<0.01).Conclusion　In conclusion, more than eight prescribed pharmaceutical medications in the elderly is associated with subjective or objective oral dysfunction.

Application of Deep Learning in the Identification of Cerebral Hemodynamics Data Obtained from Functional Near-Infrared Spectroscopy: A Preliminary Study of Pre- and Post-Tooth Clenching Assessment.

In fields using functional near-infrared spectroscopy (fNIRS), there is a need for an easy-to-understand method that allows visual presentation and rapid analysis of data and test results. This preliminary study examined whether deep learning (DL) could be applied to the analysis of fNIRS-derived brain activity data. To create a visual presentation of the data, an imaging program was developed for the analysis of hemoglobin (Hb) data from the prefrontal cortex in healthy volunteers, obtained by fNIRS before and after tooth clenching. Three types of imaging data were prepared: oxygenated hemoglobin (oxy-Hb) data, deoxygenated hemoglobin (deoxy-Hb) data, and mixed data (using both oxy-Hb and deoxy-Hb data). To differentiate between rest and tooth clenching, a cross-validation test using the image data for DL and a convolutional neural network was performed. The network identification rate using Hb imaging data was relatively high (80‒90%). These results demonstrated that a method using DL for the assessment of fNIRS imaging data may provide a useful analysis system.

The effect of a 5-year hand hygiene initiative based on the WHO multimodal hand hygiene improvement strategy: an interrupted time-series study.

BACKGROUND: A World Health Organization (WHO) guideline-based multimodal hand hygiene (HH) initiative was introduced hospital-wide to a nonteaching Japanese hospital for 5 years. The objective of this study was to assess the effect of this initiative in terms of changes in alcohol-based hand rub (ABHR) consumption and the Hand Hygiene Self-Assessment Framework (HHSAF) score. METHODS: The consumption of monthly hospital-wide ABHR was calculated in L per 1000 patient days (PDs). The change in ABHR consumption was analysed by an interrupted time series analysis with a pre-implementation period of 36 months and an implementation period of 60 months. The correlation between annual ABHR consumption and the HHSAF score was estimated using Pearson's correlation coefficients. RESULTS: The annual ABHR consumption was 4.0 (L/1000 PDs) to 4.4 in the pre-implementation period and 10.4 to 34.4 in the implementation period. The HHSAF score was 117.5 (out of 500) in the pre-implementation period and 267.5 to 445 in the implementation period. A statistically significant increase in the monthly ABHR consumption (change in slope: + 0.479 L/1000 PDs, p <  0.01) was observed with the implementation of the initiative. Annual ABHR consumption was strongly correlated with the annual HHSAF score (r = 0.971, p <  0.01). CONCLUSIONS: A 5-year WHO-based HH initiative significantly increased ABHR consumption. Our study suggested that the HHSAF assessment can be a good process measure to improve HH in a single facility, as ABHR consumption increased with the HHSAF score.

Brain activity in response to the touch of a hand on the center of the back.

The aim of this study was to validate the possibility of using functional Near-Infrared Spectroscopy (fNIRS) to measure changes in cerebral blood flow in response to a hand being placed on a participant's back, and to identify the areas of enhanced activity in the brain. Nineteen female adult volunteers participated in the study. An experienced school nurse touched the center of the participant's back between the shoulder blades with the palm of her hand. Cerebral blood volume dynamics were measured with a 52-channel fNIRS system. Significantly higher oxygenated hemoglobin (oxy-Hb) concentration levels were recorded by channels 11, 14, 21, 22, 24, 32, 35, 45, 46, and 49 during the touching period than during the resting period. These channels indicated enhanced activity in the supramarginal gyrus, the middle frontal gyrus, the superior temporal gyrus, and the inferior frontal gyrus. The ability to detect changes in cerebral blood flow using this method indicates the possibility of measuring changes in cerebral blood flow using fNIRS when a person is touched on the back. fNIRS has been shown to be useful for studying the effects of touch.

Change in the Fusion Limit by Insertion of a Middle Image Equally Dividing the Parallactic Angle of 3D Stereoscopic Images.

OBJECTIVES: The purpose of this study was to identify and clarify the requirements for 3D stereoscopic images that do not cause viewing discomfort to the human eye even when the protrusion distance is large. METHODS: A total of 140 healthy men and women aged 14 to 79 years participated in this study. We first measured the fusion limits in these participants using two 3D stereoscopic images. We then measured the expansion of the fusion limit by inserting a middle image in a region located equally parallax from the two images. RESULTS: The results showed that the fusion limits were significantly expanded (p<0.01) after inserting the middle image. CONCLUSIONS: Insertion of middle images with parallax can extend the fusion limit. This method was shown to be an effective for viewing 3D stereoscopic images without causing discomfort.

Impact of interocclusal contacts on infrared laser fluorescence in pits of sound first permanent molars in children.

BACKGROUND: A device based on infrared laser fluorescence (IRLF) has become available as an adjunct for the diagnosis of dental caries. AIMS: The objective of this study was to clarify the differences of IRLF readings in the mesial, central and distal occlusal pits of first permanent molars. DESIGN: Sixty-four children (average age 8.0 years) were examined using IRLF. The mesial, central and distal pits of clinically healthy first permanent molars were measured. The instrument provides measurements in arbitrary units on an open-ended interval scale. RESULTS: Mean (± SE) IRLF values in the mesial pits were 4.9 ± 0.4 (upper) and 6.5 ± 0.4 (lower) and were significantly lower than those in the central (8.8 ± 0.6 and 11.5 ± 0.9) and distal (9.6 ± 0.7 and 10.4 ± 0.8) pits in the maxilla and mandible. There was no significant difference between the right (7.3 ± 0.5, 9.4 ± 0.6) and left (8.2 ± 0.5, 9.5 ± 0.6) dental arches. IRLF measurements in the mesial pits of human first permanent sound molars were lower than the central and distal pits in children whose second molars had not erupted. CONCLUSIONS: The inherently higher IRLF values of some sites should not be misinterpreted and trigger early invasive treatment.

Is there a relationship between periodontal disease and smoking after adjusting for job classification in Japanese employed males?

OBJECTIVES: The objective of this study is to examine whether the well-known association between periodontal disease and smoking persists after adjusting for job classification. METHODS: A sample of 16,110 employed Japanese males aged 20-69 years was included in the study. Periodontal examinations were conducted using the Community Periodontal Index. The association between periodontal disease and smoking status was examined using logistic regression adjusting for age, diabetes and job classification. Job classification was based on criteria of the Japanese Ministry of Health, Labour and Welfare. There are nine major job groups: (1) Professional (professionals, specialists), (2) Managers, (3) Office workers (computer operators, clerks, secretaries), (4) Skilled worker (factory workers, construction workers), (5) Salesperson (shop assistants), (6) Service occupations (superintendents, cleaners or car park attendants), (7) Security (guards), (8) Farmers and fishermen, (9) Transport and telecommunication workers (truck drivers). RESULTS: Current and former smokers were more likely to have periodontal disease than non-smokers. Adjusting for job classification attenuated the association between smoking and periodontal disease but did not eliminate the association. The odds ratios for the association between smoking and Community Periodontal Index score 3 or 4 attenuated from 2.25 to 2.04 and from 2.62 to 2.52 for individuals aged 20 to 39 and 40 to 69 years, respectively. The effect of job classification on the association between periodontal disease and smoking was higher among younger participants aged 20 to 39 years. CONCLUSIONS: Smoking persisted as an important determinant of periodontal disease after adjusting for job classification in Japanese employed males.

Relationships between mandibular cortical bone measures and biochemical markers of bone turnover in elderly Japanese men and women.

OBJECTIVE: The aim was to clarify the association between dental panoramic radiography measures of mandibular inferior cortical shape and biochemical markers of bone turnover in elderly men and women. STUDY DESIGN: Subjects were 80-year-old men (n = 85) and women (n = 153). Mandibular cortical shape and width were evaluated on dental panoramic radiographs. Bone formation and resorption, respectively, were estimated by serum levels of carboxy-terminal propeptide of type I collagen (PICP) and serum type I collagen carboxy-terminal telopeptide (ICTP). RESULTS: Eroded cortices of the mandible were significantly associated with increased serum PICP levels (P = .005) in women. Lower mandibular cortical width quartiles were also significantly associated with increased serum PICP levels in men (P = .020) and women (P = .006). CONCLUSIONS: Mandibular inferior cortical measures detected on dental panoramic radiographs may be associated with bone formation rates and be useful in predicting osteoporosis in elderly Japanese men and women.

Temporal association of elevated C-reactive protein and periodontal disease in men.

BACKGROUND: Most studies on the relationship between serum C-reactive protein (CRP) and periodontal disease have been cross-sectional. In this study, we investigated the temporal association between CRP and periodontal disease by following a large number of subjects for 1 year. METHODS: We studied 11,162 men in Nagoya, Japan, who had an initial dental examination as part of a complete physical examination and then underwent the same examination 1 year later. For the 4,997 men without periodontal disease at baseline, logistic regression analysis was performed to examine the relationship between baseline CRP and periodontal disease 1 year later, adjusting for age, body mass index, glycosylated hemoglobin A1c level, and smoking status. Similarly, logistic regression analysis was performed to examine the relationship between periodontal disease at baseline and CRP 1 year later for the 10,376 men with normal baseline CRP, adjusting for the same confounding factors. RESULTS: Among men without high CRP at baseline, periodontal disease at baseline correlated to CRP 1 year later. The odds ratio was 1.336 (95% confidence interval [CI]: 1.115 to 1.674). However, in the men without periodontal disease, no significant correlations were seen with baseline CRP or periodontal disease 1 year later. The odds ratio was 1.163 (95% CI: 0.894 to 1.513). CONCLUSION: Periodontal disease increased the risk for high serum CRP levels in men after 1 year of follow-up.

[A pilot study to develop a screening system and maltreatment index for elementary schoolchildren focusing on daily habits and dental caries].

OBJECTIVE: In recent years, the number of consultations for maltreatment cases has been increasing in Japan. The characteristics of maltreated children are important factors for their identification. In an earlier paper, we analysed the daily habits related to maltreated children. In the present study, the objectives were to assess the relative weights of each factor and score the daily habits and treatment percentages for dental caries, and also to develop a screening system to find maltreated children. METHODS: The subjects of this study were 57 elementary schoolchildren who were given temporary protection by the child social welfare authorities. The control group comprised 575 elementary schoolchildren. Multiple logistics regression analysis was used to calculate scores for each item derived from partial correlation coefficients. RESULTS: Two versions of a maltreatment index for elementary schoolchildren (MIES) were developed, a daily habits version (H) and daily habits and treatment percentage of dental caries version (HD) for the 1st to 3rd grades (G1-3) and the 4th to 6th grades (G4-6). The MIES for G1-3H was: Do you brush your teeth before bedtime (3 points); Do you know that the first molars are important for chewing (2); Have you used a fluoride gel or mouth rinse (2); Do you have any hobbies except video games (2); Do you know the differences between permanent teeth and milk teeth (1). The MIES for G1-3HD were: Have you used a fluoride gel or mouth rinse (4); Do you brush your teeth before bedtime (3); Do you wash your hands after you play outside (2); Is the number of untreated deciduous teeth larger than the number of treated deciduous teeth (1). The MIES for G4-6H were: Do you wash your hands after you play outside (4); Do you brush your teeth after breakfast (3); Do you brush your teeth before bedtime (3). The G4-6HD were: Do you brush your teeth before bedtime (3); Do you wash your hands after you play outside (2); Is the number of untreated permanent teeth greater than the number of treated permanent teeth (1). The availability (sensitivity + specificity) of MIES HD was higher than MIES H when the original values were substituted into MIES. CONCLUSIONS: A screening system for finding maltreated children for MIES was designed. The precision of MIES could be improved by adding the treatment percentage of dental caries to daily habits.

[An intervention comparison of dental hygienist visits and leaflet mailing for improvement of oral health scores in village residents].

PURPOSE: This study was undertaken to clarify to what extentintervention by dental hygienist visits and leaflet mailing, once or three times a year, increased the dental health scores of Tobishima Village residents in a 3 year period. METHODS: The oral health status and oral health score (the Oral Salutogenic Score) of 786 residents were examined in May, 2004. Of the total, 446 people had oral health scores equal to or less than 15. They were divided into three groups at random, receiving: dental hygienist visits (visit group); leaflet mailing three times a year (three times mail group); and leaflet mailing only once a year (single mail group). Oral health status and scores were examined a second time by dentists in May, 2007 and average increases of scores over 3 years were calculated for each of the three groups. The Mann-Whitney test and cost-effectiveness analysis were employed for comparisons. RESULTS: The average increase in oral health score was 46.2 +/- 8.1% for the visit group, 31.2 +/- 4.4% for the three times mail group and 25.0+/-5.2% single mail group over 3 years. The visit group value was significantly higher than the single mail group (P<0.05). Of the resi-dents who had an oral health score equal to or less than 15 points, increase of their oral health score those who received a dental hygienist visit had a higher than the groups who were sent leaflets. With the latter, the greater frequency of leaflet distribution was more effective for increasing the oral health score. CONCLUSION: It was concluded that visits by dental hygienists are more effective than mailing of leaflets. In addition, mailing 2 or 3 times a year is more effective than once a year.

Development of an oral salutogenic checklist to promote lifelong oral health in Japanese adults.

PURPOSE: The aim of this study was to assess the relative weights of each factor related to tooth retention identified in our previous study with an objective of developing a risk assessment tool that could be incorporated into a self-administered oral salutogenic checklist. MATERIALS AND METHODS: Oral health status and lifestyle were investigated in 777 subjects aged > or = 20 years. Eleven items that had a statistically significant odds ratio of being related to the number of retained teeth in our previous study were identified. Discriminant analysis was used to calculate the scores for each item. RESULTS: Based on the discriminant analysis, the variables affecting tooth retention, from the most to the least important, were 'gum swelling' (1.241), followed by 'toothache' (0.766) and 'do you have any hobbies' (0.691). Based on the above analysis, a total of 20 points were allocated in proportion to the ranges. The final oral salutogenic score (OSS) was swollen gums (4), toothache (3), frequency of between-meal snacks (3), having some hobbies (3), having a family clinician (2), consulting a clinician when having dental symptoms (1), bleeding gums (1), frequency of tooth brushing (1), having one's own toothbrush (1) and smoking (1). CONCLUSIONS: A self-administered checklist for the OSS was designed. The first part contains a list of questions for the participants to fill out. The second part offers comments depending on the range of score values. The suggestions include advice to decrease or to stop the behaviours for which the subject obtained zero points.

Gradients in periodontal status in Japanese employed males.

AIM: The objective was to assess whether there was a social gradient in periodontal status by job classification in Japanese male workers. MATERIAL AND METHODS: Study participants were 15,803 Japanese male workers aged 20-69 years. There were seven groups classified by jobs. Oral examinations were conducted using community periodontal index (CPI). RESULTS: The percentages of sextants with a CPI score of 3 or 4 of professionals were significantly lower than for other job classes. The gradient also existed for the percentage of sextants with CPI score 4. After adjusting for age, a history of diabetes mellitus and smoking status, those lower on the gradient, namely, drivers, service occupations, salespersons and managers were 2.0, 1.5, 1.4 and 1.4, times, respectively more likely to have one or more sextants with CPI score 3 or 4 compared with professionals. Odds ratios of having more than one or more sextants with CPI score 4 after adjusting for age, clinical history of diabetes mellitus and smoking status for drivers, service occupations, salespersons and managers were 2.1, 1.5, 1.5 and 1.2, respectively, compared with professionals. CONCLUSIONS: There was a gradient in periodontal status by job classification. Professional and office workers had better periodontal status than salespersons, service occupations and drivers.

Is there a gradient by job classification in dental status in Japanese men?

The objective of this study was to assess whether there is a gradient in dental health status by job classification in male Japanese workers. The study subjects were 16,261 male Japanese workers aged 20-69 yr. Jobs were classified into seven job groups. Oral examination was conducted using World Health Organization criteria for decayed, missing or filled teeth (DMFT). Professionals, managers, and office workers had a better oral status than those in service occupations and drivers. Professionals had significantly more natural and sound teeth than those in other job classes. The DMFT of professionals was significantly lower than in workers of other job classes. Professionals had a significantly higher restorative index than did workers of other job classes. The restorative index of office workers was significantly higher than that in managers, skilled workers, salespersons, those in service occupations, and drivers. Drivers were 1.8 times, and those in service occupations 1.3 times, more likely to have one or more carious teeth compared with professionals. Skilled workers, salespersons, those in service occupations, and drivers were 1.3, 1.3, 1.4, and 2.1 times, respectively, more likely to have a missing tooth compared with professionals. Skilled workers, those in service occupations, and drivers were 1.7, 1.9, and 3.1 times, respectively, more likely not to have 20 or more teeth compared with professionals aged 50-69 yr.

Salutogenic factors that may enhance lifelong oral health in an elderly Japanese population.

OBJECTIVES: The objective of this study was to assess which factors affected the maintenance of more than 20 teeth in Japanese patients aged 80 years and older, using a life-course perspective. SUBJECTS AND METHODS: The oral examination was carried out by dentists. The questionnaire asked about family background, background during various stages of growing up, tooth brushing, snacking, job history, health examination, war experience, number of children, oral health condition and dietary preferences. Some of the questions asked about conditions when they were a primary school student, 20 years old, 40 years old and 60 years old. Multivariable logistic-regression analysis was used to adjust for sex at significant life stages. RESULTS: The group with mothers who did not prefer sweet food had an approximately four times greater chance of having >or=20 teeth compared with the group with mothers who preferred sweet food. Those participants who did not prefer sweet food themselves were approximately three to five times more likely to be in the >or=20 tooth group compared with those who preferred sweet food at all stages of their life course. Non-smokers and those who quit smoking were three times more likely to be in the >or=20 tooth group than those who smoked throughout the years from 20 to 60 years of age. CONCLUSIONS: Factors associated with the maintenance of a sufficient number of functioning teeth were: not having a mother with a preference for sweet food, not having a preference for sweet food themselves and not smoking over a long period.

Behavioral factors to include in guidelines for lifelong oral healthiness: an observational study in Japanese adults.

BACKGROUND: The aim of this study was to determine which behavioral factors to include in guidelines for the Japanese public to achieve an acceptable level of oral healthiness. The objective was to determine the relationship between oral health related behaviors and symptoms related to oral disease and tooth loss in a Japanese adult community. METHODS: Oral health status and lifestyle were investigated in 777 people aged 20 years and older (390 men and 387 women). Subjects were asked to complete a postal questionnaire concerning past diet and lifestyle. The completed questionnaires were collected when they had health examinations. The 15 questions included their preference for sweets, how many between-meal snacks they usually had per day, smoking and drinking habits, presence of oral symptoms, and attitudes towards dental visits. Participants were asked about their behaviors at different stages of their life. The oral health examinations included examination of the oral cavity and teeth performed by dentists using WHO criteria. Odds ratios were calculated for all subjects, all 10 year age groups, and for subjects 30 years or older, 40 years or older, 50 years or older, and 60 years or older. RESULTS: Frequency of tooth brushing (OR = 3.98), having your own toothbrush (OR = 2.11), smoking (OR = 2.71) and bleeding gums (OR = 2.03) were significantly associated with number of retained teeth in males. Frequency of between-meal snacks was strongly associated with number of retained teeth in females (OR = 4.67). Having some hobbies (OR = 2.97), having a family dentist (OR = 2.34) and consulting a dentist as soon as symptoms occurred (OR = 1.74) were significantly associated with number of retained teeth in females. Factors that were significantly associated with tooth loss in both males and females included alcohol consumption (OR = 11.96, males, OR = 3.83, females), swollen gums (OR = 1.93, males, OR = 3.04, females) and toothache (OR = 3.39, males, OR = 3.52, females). CONCLUSION: Behavioral factors that were associated with tooth retention were frequency of eating snacks between meals, tooth brushing frequency, having one's own toothbrush, smoking and drinking habits, having hobbies, having a family dentist and when they had dental treatment. Clinical factors included bleeding gums, swollen gums, and toothache.