Increasing number of teeth present in a quasi-longitudinal study in adults: a methodological note

This paper discusses the impossible result of an increase in the number of teeth present in a quasi-longitudinal study of an adult population. In 1983 and 1994, random samples were drawn from birth cohorts 1939–48 and 1930–38. The paradoxical result that adults acquired new teeth in the quasi-longitudinal study gave rise to questions about the comparability of the two samples. Four main sources of failure in comparability are described and discussed: instrumental stability, criteria consistency, response bias, and compositional change in aging cohorts. The lower response rate among persons with two edentulous jaws, and possibly among persons with one dentate jaw, was concluded to be the main reason for the increase in the overall group median and mean number of teeth present. In general, in studies with a similar study design, problems of comparability between the samples demand ones attention and should therefore be carefully evaluated. Compositional change of the population as a source of failure in sample comparability cannot be avoided, while the other three sources (instrumental stability, criteria consistency, response bias) can largely be avoided by careful planning and efficient use of resources.     

Oral health changes in an adult Norwegian population: a cohort analytical approach

Abstract – Objectives: The purpose of this analysis was to study temporal variation in oral health in an adult population. The cohort analysis comprised 1) estimation of longitudinal, cross‐sectional, and time‐lag differences in caries and treatment experience of the adult population in Trøndelag from 1973 to 1983 and to 1994; 2) assessment of which of the effects of age, period and cohort was the most plausible explanation for the observed differences and 3) discussion of causal and other factors underlying the effects of age, period and cohort. Methods: Cohort analysis was used to study changes in oral health over time. Study participants were selected by random sampling in 1973, 1983, and 1994 (n=1959, n=3195, n=2341 respectively). The methods of data collection comprised standardised clinical measurements and a self‐administered questionnaire. Cohort tables were established to analyse changes in DFT from 1973 to 1983 and DFT and DFS from 1983 to 1994. Results: Four patterns of changes in oral health were identified from adolescence to older adulthood. They point in different directions which indicate that complex processes are present. There were two and three significant changes in the subsets of analysis. Assumptions and conditions that allow identification of separate cohort, period, and age effects appeared not to be present. The pattern of changes was consistent with main effects of both age, period, and cohort. The effects were discussed from the perspective of the chosen frame of explanatory factors. Conclusions: The changes in oral health between populations in 1973, 1983 and 1994 were the combined consequences of simultaneously occurring factors that account for both age, period and cohort effects.     

Caries prevalence and distribution in 20-80-year-olds in Jönköping, Sweden, in 1973, 1983, and 1993

Abstract – In 1973, a cross‐sectional study on oral health status was performed on 1000 individuals in the age groups 3–70 years in Jönköping, Sweden. In 1983 and 1993, new cross‐sectional studies were carried out in the age groups 3–80 years. The aim of the present study was to analyze caries prevalence and distribution in the three investigations 1973, 1983, and 1993 in the age groups 20–80 years. In the younger age groups (20–40 years), a larger proportion of individuals with good oral health was found in 1993 than in 1973 or 1983. A steady increase in the number of teeth in the age groups 40–80 years could be found, which was also reflected in the increasing number of decayed and filled tooth surfaces (DFS) in the same age groups. A marked decrease in proximal DFS in 20–50‐year‐olds in 1993 compared to 1973 and 1983 was found. However, a rather large and unchanging group of individuals suffering from severe caries was also observed. This situation demands an individualized caries treatment strategy based on risk assessment.     

Oral health impacts among adults in Finland: competing effects of age, number of teeth, and removable dentures

The aims of the present study were to evaluate the prevalence and severity of oral health impacts among adults and to analyse the effects of age, gender, level of education, number of teeth, and removable denture wearing on these impacts. Nationally representative data ( n  = 5,987) on Finnish adults aged 30+ yr were gathered in an interview, in a clinical examination, and by a questionnaire including the 14-item Oral Health Impact Profile. Subject age and the number of teeth were significantly associated with oral impacts (occurring fairly or very often) when the effects of gender, educational level, and removable dentures were considered. When subjects ≥ 75 yr of age were used as the reference group, the odds ratios (95% confidence interval) were 0.5 (0.3–0.8) and 0.7 (0.5–0.9) for 30–34-yr-old and 34–74-yr-old subjects, respectively. The odds ratios for those with 1–9 teeth and for those who were edentate were 3.4 (2.4–4.9) and 4.0 (2.6–6.3), respectively (20+ teeth as reference). Number of teeth modified the effect of denture wearing, and age modified the effect of educational level on oral impacts. Impaired subjective oral health related to many missing teeth might be improved by wearing removable dentures. Population groups needing special attention are young people with low education and those for whom only a few missing teeth are replaced with removable dentures.     

Oral health of individuals aged 3-80 years in J?nk?ping, Sweden, in 1973 and 1983. II. A review of clinical and radiographic findings

The aim of this study was to present data from clinical and radiographic examinations on oral health in two cross-sectional studies carried out in 1973 and 1983. A random sample of approximately 1000 individuals, evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60 and 70 years was studied for each of these two years. In the 1983-year examination 80 individuals, 80 years of age, were also included. All subjects were inhabitants of the community of J?nk?ping, Sweden. The clinical and radiographic examination assessed edentulousness, removable dentures, number of teeth, caries, restorations and overhangs, gingival and periodontal status, oral hygiene and calculus, endodontic treatment and periapical status. A reduction in number of edentulous individuals by 25% was recorded between the two examinations. This was matched by an increase in the mean number of teeth, mainly of molars. The largest difference in mean number of teeth between the 1973 and 1983 examinations was found for the 70-year-olds. These were 8.5 and 11.8 teeth respectively. The younger age groups showed an increase in the proportion of individuals free from caries and restorations. In 1973 the caries-free proportions were 35% for 3-year-olds and 9% for 5-year-olds. In 1983 these values had improved to 70% and 29% respectively. Corresponding to this trend the number of decayed tooth surfaces was lower in 1983. Fewer filled tooth surfaces were present 1983 compared with 1973 for the age groups 10, 15, 20 and 30 years but higher for the age groups 5, 50 and 60 years and unchanged for the remaining groups. For the younger age groups the overall reduction in DFS was about 50% but this increased to 90% for buccal and lingual surfaces. Both secondary caries and overhanging restorations had decreased in the 1983 group for all ages. At least 75-86% of restorations were without overhangs in 1983 compared to 47-65% in 1973. Gingival health had improved over the 10-year period. Sites with plaque and calculus and gingival units exhibiting gingivitis had all decreased in frequency by 1983. Buccal surfaces showed the greatest improvement. The frequency of individuals with one or more periodontal pockets (greater than or equal to 4 mm) increased with age but was of the same distribution in 1983 as in 1973.(ABSTRACT TRUNCATED AT 400 WORDS)     

Root caries patterns and risk factors of middle-aged and elderly people in China

Abstract –  The objectives of this study were to describe root caries patterns of Chinese adults and to analyze the effect of selected demographic and socioeconomic factors on these patterns. A total sample of 1080 residents aged 35–44-years-old and 1080 residents aged 65–74-years-old from three urban and three rural survey sites in Hubei Province participated in both an oral health interview and a clinical oral health examination. Root surface caries prevalence rates were 13.1% in the middle-aged group and 43.9% in the elderly group. The mean number of teeth affected by caries in the middle-aged group was reported at 0.21 and 1.0 in the elderly group. Mean Root Caries Index (RCI) scores of the middle-aged were reported at 6.29 and elderly subjects were reported at 11.95. Elderly people living in rural areas reported a higher RCI score (13.24) than those living in urban areas (10.70). A significantly higher frequency of root surface caries was observed in elderly participants ( P  < 0.001, OR = 3.80) and ethnic minorities ( P  < 0.001, OR = 1.93). In addition, smokers, nontea drinkers, and those with an annual household income of 10 000 yuan or less tended to have higher caries prevalence. RCI figures for the different tooth types ranged from 1% to 16%, indicating a wide variation in attack rates. In conclusion, our study suggests that root surface caries occurrence is high among the Chinese adult population, especially older adults. With an increasing number of retained teeth in both middle-aged and elderly people, root caries is a growing disease in the People's Republic of China which deserves more attention in future research.     

Clinical factors and self‐perceived oral health

Self‐perceived oral health is affected not only by awareness of the clinical status but also by comparisons with people of a similar age. This study explored the relative contributions of clinical variables assessing caries, periodontal status, and prosthetic status to self‐perceived oral health within two age groups. Data of 891 adults (35–44 yr of age) and 760 older people (65–74 yr of age) from the Fourth German Oral Health Study (DMS IV, 2005) were evaluated. Self‐perceived oral health was obtained from questionnaires. Numbers of decayed, filled, and unreplaced teeth, mean attachment loss, bleeding on probing (BOP), the presence of a fixed denture, and the presence of a removable denture were assessed. Multinomial logistic regression models were developed for both age groups, separately, using stepwise methods. For adults, unreplaced teeth, filled teeth, decayed teeth, the presence of a removable denture, and mean attachment loss were added to the final model. For older people, the presence of a removable denture, unreplaced teeth, decayed teeth, mean attachment loss, filled teeth, and BOP were included in the final model. Awareness of the relative contributions of clinical variables to self‐perceived oral health is important for obtaining a clearer understanding of patients' subjective and objective self‐perceptions of oral health.     

Oral health of individuals aged 3-80 years in Jönköping, Sweden during 30 years (1973-2003). II. Review of clinical and radiographic findings

The aim of this epidemiological study was to analyze various clinical and radiographic data on oral health and compare the results to those of three cross-sectional studies carried out in 1973 and 1983, and 1993. In 1973, 1983, 1993, and 2003 a random sample of 1,000; 1,104; 1,078; and 987 individuals, respectively, were studied. The individuals were evenly distributed in the age groups 3, 5, 10, 15, 20, 30, 40, 50, 60, 70, and 80 years. In 1973 80-year-olds were not included. All subjects were inhabitants of the City of J?nk?ping, Sweden. The clinical and radiographic examination assessed edentulousness, removable dentures, implants, number of teeth, caries, restorations and overhangs, oral hygiene, calculus, periodontal status, endodontic treatment, and periapical status. The number of edentulous individuals in the age groups 40-70 years was reduced from 16 per cent in 1973 to 8 per cent in 1993, and to 1 per cent in 2003. The mean number of teeth increased, and up to the age of 60 years, individuals had more or less complete dentitions. During the 30-year period,the number of carious lesions and restorations decreased in general. In the 15-year-olds the decrease in number of restored tooth surfaces was 900 per cent and the corresponding figure for 30-year-olds was 79 per cent. The age groups 60-800 years showed an increase in number of restored tooth surfaces and had as a mean 50 filled tooth surfaces. The oral health among 3-5-year-olds improved markedly between 1973 and 1993. In 2003, however, there was no further improvement in 3- and 5-year-olds compared to 1993. Generally, restorations in 2003 exhibited a high quality and 90-95 per cent had no proximal overhangs. In 1973 this figure was about 60 per cent. In the age groups 20-50 years there were continuously fewer teeth fitted with crowns or bridges during the 30-year period. In 1973 the 50-year-olds had a mean of 24.5 per cent of the teeth crowned and in 2003 6.8 percent. Compared to data from 1973 there was a reduction by half concerning occurrence of plaque and gingivitis in 2003. The frequency of individuals with one or more periodontal pockets (> or = 4 mm) increased with age. In 2003 the bone level at the age of 60 years corresponded to the bone level at the age of 40 years in 1973. The percentage of endodontically treated teeth was lower in 2003 in all age groups compared to 1973, 1983, and 1993. The percentage of endodontically treated teeth with periapical orjuxtaradicular destructions was generally lower in 2003 than in the earlier surveys, about 20 per cent in 2003 compared to 25-30 per cent in 1973,1983, and 1993. The comparison of the four studies shows that there has been a great overall improvement in oral health over this 30-year period.     

Assessment of predictors of global self‐ratings of oral health among Korean adults aged 18‐95 years

Objectives: The aims of this study were to assess predictors of global self‐ratings of oral health (GSROH) and to examine whether they varied by age among Korean adults aged 18‐95 years. Methods: Data from 4,546 adults aged 18‐95 years completing the Korean National Oral Health Survey 2006 were included in the analysis. Results: Subjects' mean age was 43.5 years, with 12.1 percent aged ≥65 years; 47.8 percent were men; and 2.5 percent were edentulous. The predictors of GSROH in adults were number of missing teeth, concern about oral health, and difficulty in chewing. While wearing removable dentures was associated only in elders, perceived treatment need was associated in younger age groups. The number of decayed and filled teeth was significant only in the 18‐44 age group. Conclusions: GSROH status was associated with measures of oral disease, oral functional problems, oral health behaviors, concerns, and perceived treatment needs, and it varied by age.     

Caries prevalence and distribution in individuals aged 3–20 years in Jönköping, Sweden, over a 30-year period (1973–2003)

Background.  Oral health status of individuals aged 3–80 years in the city of Jönköping, Sweden, has been assessed in a series of epidemiological studies over a 30-year period.
Aim.  To analyse the changes in caries prevalence and caries distribution in child population sample groups, based on studies performed in 1973, 1978, 1983, 1993, and 2003.
Design.  Each time point included 500 randomly sampled individuals, divided into age groups of 3, 5, 10, 15, and 20 years.
Results.  Thirty-five per cent of 3-year-olds were caries free in 1973, compared with 69% 30 years later. Decayed and filled primary (dfs) and permanent surfaces (DFS) were reduced by 50–80% between 1973 and 2003. Adolescents aged 10 and 15 years exhibited the most pronounced reduction in DFS on the occlusal surfaces. By 2003, 90% of the proximal carious lesions in 15-year-olds were initial carious lesions. In 2003, about 60% of 15-year-olds had a DFS of ≤ 5, while about 7% exhibited a DFS of ≥ 26.
Conclusions.  Despite the dramatic decline in the prevalence of caries, caries remains a health problem among children, particularly those of preschool age. Continuous epidemiological studies are recommended to evaluate preventive measures.     

Oral health: perceptions of need in a rural Iowa county

Several studies have shown that oral health problems impact the quality of life of older adults. However, few data are available to describe the oral health status, barriers to care, and patterns of care for adults and older populations living in rural areas. The purpose of this study was to evaluate the perceived need for treatment of oral health problems by adult residents in a rural county in Iowa.
The oral health component was part of a larger longitudinal health study of the residents. The sample was stratified into three groups by residence, that is, farm households, rural non-farm households and town households. The sample was subsequently post-stratified by gender and age group into young elderly, 65–74 years old, and old elderly, 75 years and older.
Dentition status varied according to age and was related to the perception of treatment needs. Edentulous persons had fewer perceived treatment needs and utilized a dentist less frequently. Place of residence, education, and marital status were not associated with the subjects' perceived problems with eating and chewing. However, persons with difficulty chewing were more likely to have some missing upper teeth, have a perceived need to have denture work, and have smoked for a number of years. The results suggest that this rural population is retaining more teeth and consequently may need and may seek dental services more often than previous more edentulous cohorts.     

Prediction of Periodontitis Occurrence: Influence of Classification and Sociodemographic and General Health Information

Background: Prediction of periodontitis development is challenging. Use of oral health–related data alone, especially in a young population, might underestimate disease risk. This study investigates accuracy of oral, systemic, and socioeconomic data on estimating periodontitis development in a population‐based prospective cohort. Methods: General health history and sociodemographic information were collected throughout the life‐course of individuals. Oral examinations were performed at ages 24 and 31 years in the Pelotas 1982 birth cohort. Periodontitis at age 31 years according to six classifications was used as the gold standard to compute area under the receiver operating characteristic curve (AUC). Multivariable binomial regression models were used to evaluate the effects of oral health, general health, and socioeconomic characteristics on accuracy of periodontitis development prediction. Results: Complete data for 471 participants were used. Periodontitis classifications with lower thresholds yielded superior predictive power. Calculus, pocket, or bleeding presence at age 24 years separately presented fair accuracy. Accuracy increased using multivariable models; for example, the Beck et al. classification AUC from 0.59 to 0.75 combining proportion of teeth with calculus, bleeding, or pocket with income; number of lost teeth; sex; education; people living in the house; prosthetic needs; or number of decayed, missing, or filled teeth (DMFT). Proportion of teeth with pocket, bleeding, or calculus; number of DMFT; toothbrushing frequency; blood pressure; sex; and income were most frequently associated. Conclusions: Choice of classification might have an impact on accuracy to predict periodontitis occurrence. Regardless of the classification, predictive value for development of periodontitis in young adults might be increased by combining periodontal information, sociodemographic information, and general health history.     

Oral health knowledge, attitudes, and practices of Chinese adults.

Only recently have behavioral aspects been taken into consideration in oral health studies in China; thus, relevant information on perceptions in adult Chinese about oral health care is inadequate. In 1996-97, a large-scale oral epidemiological study was conducted in Southern China. Among its objectives were to describe the oral health knowledge, attitudes, and practices of the urban and rural adults living in Southern China and to analyze the influence of selected demographic and socio-economic factors. From 8 urban and 8 rural communities in Guangdong Province, 1,573 35- to 44-year-olds and 1,515 65- to 74-year-olds were sampled. Specially trained interviewers from the staff of local government or hospitals conducted face-to-face structured interviews. Almost all of the middle-aged and more than 90% of the dentate elderly surveyed claimed that they brushed their teeth every day and used toothpaste during toothbrushing, but awareness about fluoride content was lacking. The respondents had poor oral health knowledge but positive attitudes toward oral health, providing a basis for more community-based oral health education programs, especially targeting adults who are less-well-educated and have fewer socio-economic advantages.     

Satisfaction with teeth and life-course predictors: a prospective study of a Swedish 1942 birth cohort

Ekbäck G, Nodrehaug-Åstrøm A, Klock K, Ordell S, Unell L. Satisfaction with teeth and life-course predictors: a prospective study of a Swedish 1942 birth cohort. Eur J Oral Sci 2010; 118: 66–74. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci
This study aimed to assess the stability or change in satisfaction with teeth among Swedish adults between the ages of 50 and 65 yr, and to identify the impact of socio-demographics and of clinical and subjective oral health indicators on participants' satisfaction with teeth during that period. Self-administered standardized questionnaires were used as part of a longitudinal study. In 1992, 1997, 2002, and 2007 all residents (born in 1942) of two Swedish counties were invited to participate in the study. A total of 63% women and 66% men reported being satisfied with their teeth between 50 and 65 yr of age. The corresponding figures, with respect to dissatisfaction, were 7% and 6% respectively. Generalized estimated equation models revealed a decline in the odds of being satisfied with advancing age, which was particularly important in subjects with lower education, tooth loss, and smokers. Consolidation in oral health perceptions starts before age 50, suggesting early intervention before that age. Promotion of a healthy adult lifestyle and improved access to quality oral healthcare might increase the likelihood of people being satisfied with their teeth throughout the third age-period in both genders.     

Oral hygiene and gingivitis in a Swedish adult population 1973, 1983 and 1993

Abstract. The periodontal condition of the inhabitants of Jönköping County, Sweden was followed for 20 years by means of 3 cross-sectional investigations performed in 1973, 1983, and 1993. The study comprised individuals in the age groups 20, 30, 40, 50, 60, and 70 years. The number of dentate individuals was 537 in 1973, 550 in 1983, and 552 in 1993. All individuals participating in the studies were examined clinically and radiographically. They also filled out a questionnaire about dental care habits, socio-economic status, and general health. A clear reduction in the plaque score was seen between 1973 and 1983 in all age groups. With one exception, no further significant change in plaque levels was found between 1983 and 1993: the increase in plaque among the 20-year-olds was significant. In 1993 the mean % of surfaces with plaque was between 30% and 40% in all age groups. Gingivitis values corresponded well with the values of dental plaque: the same pattern with a clear reduction in gingivitis score was seen in all age groups between 1973 and 1983, and an increase in the mean frequency of gingival inflammation between 1983 and 1993 was seen in the 20-year age group. 30% of the individuals in this age group had more than 50% gingivitis in 1993 compared with 9% of the individuals in 1983. The 20-year-olds were further analyzed in a linear regression model using gingivitis as a dependent variable against some socio-economic, general health, and dental care variables associated with poor oral hygiene and gingivitis. In 1993, the most important explanatory variable was gender: significantly more males than females had higher gingivitis scores. The second most important explanatory variable was toothbrushing habits. Together they explained 10.9% of the variance. The multivariate analysis did not reveal approximal cleaning habits to be significant, probably due to their strong connection to gender and toothbrushing habits. In the 1983 sample, no significant explanatory variables were found. It was concluded from this data that it is important not only to renew but also to direct preventive guidelines more towards young adults who have no previous extensive experience of oral disease so that they will not be excluded from dental care and their dental health thereby jeopardised. In addition to preventive programmes aimed at the population as a whole, individual programmes based on risk targeting are also necessary to reduce the number of people developing dental disease and to increase the quality of dental care.     

Caries experience among publicly-funded dental patients in Australia, 1995-96: type of care and geographic location

Health card holders are a financially disadvantaged group and are the target population eligible for publicly-funded dental care. While their health status is generally worse compared with other Australians, there is also considerable variation among card holders. The aims of this study were to describe the oral health status of publicly-funded dental patients by type of care, geographic location and age, and to compare trends over time against other Australian studies. Patients were sampled randomly, based on date of birth, by State/Territory dental services in 1995-96. Dentists recorded oral health measures at the initial visit of a course of care using written instructions, but there was no formal calibration. The 6109 patients sampled were weighted in proportion to the numbers of publicly-funded dental patients for each State/Territory. Multiple linear regression analysis indicated that caries experience measured by the DMFT index increased across older age groups (p < 0.05). For rural compared with urban patients, mean numbers of decayed and filled teeth tended to be higher. For emergency compared with non-emergency care, mean numbers of decayed and missing teeth were higher, and filled teeth lower. The findings of this monitoring survey document high levels of previous disease and treatment and indicate variation between subgroups of users of publicly-funded dental care. This included an uneven geographic distribution of oral health and disease, and variation in unmet treatment needs by type of course of care. Temporal comparisons indicate publicly-funded patients have experienced the population trend towards lower levels of tooth loss over time but have higher levels of untreated decayed teeth compared with the general population.     

Oral health,sense of coherence and dental anxiety among middle-aged women

Abstract

Aims. The specific aims of this investigation were to analyze the relationship between sense of coherence (SOC), dental anxiety (DA) and oral health status among middle-aged women, measured both subjectively and objectively and adjusted for socioeconomic status (SES). Materials and methods. Randomly selected women, 38 (n = 206) and 50 (n = 287) years of age, were included in a cross-sectional health examination. The participants underwent a series of examination stages, including a clinical and dental radiographic examination. The women responded to questionnaires concerning SES, oral health, DA and SOC. Results. The number of teeth was significantly related to SOC, where more missing teeth revealed a lower SOC level among 50-year-olds. The variables of caries, apical periodontitis and filled surfaces were not statistically significantly associated with SOC. However, the self-reported measure of oral health was associated with SOC in both age groups. High DA was significantly related to self-perceived poor oral health regardless of age. Individuals with high DA also had fewer teeth, more filled surfaces and more approximal caries. The multivariate models showed that higher SOC levels were associated with better oral health, as estimated by objective or subjective measures, while the inverse results were seen for DA. Thus, individuals reporting high DA were more likely to have fewer teeth and poor perceived oral health, taking SES into account. Conclusions. Sense of coherence and dental anxiety are psychological aspects with respect to health- and risk-factors of oral health.     

Oral Disease Beliefs, Behaviors, and Health Status of Korean-Americans

Previous research with other ethnic minorities has shown that culture and age cohort, as well as language and economic limitations, act as barriers to obtaining dental care and maintaining good oral health. This study compared self-reported oral health attitudes, self-efficacy, and dental practices of 20 younger and 23 elderly Korean-Americans. Oral assessments were also conducted to determine plaque and gingival status, and root and coronal caries. Significant differences emerged in health self-efficacy (P less than .01) and preventive health orientation (P less than .002). Elderly had fewer teeth (P less than .0001), more decayed and filled root surfaces (P less than .05 and P less than .004, respectively), and more decayed and filled coronal surfaces (P less than .001 and P less than .03). Both groups showed higher levels of distal and mesial plaque than occlusal and cervical plaque; however, the elderly had higher rates of both (P less than .0001). Gingival status was also worse for the elderly, on distal and mesial (P less than .01), facial (P less than .01), and lingual (P less than .01) surfaces. These differences are striking, since the elderly reported visiting the dentist more recently (P less than .0001); but most of these visits were for prosthodontic and emergency care. Better preventive dental care and education are necessary for elderly immigrants who have not been exposed to preventive dentistry in their home countries.     

The Japanese version of the Oral Health Impact Profile (OHIP)--validation among young and middle-aged adults

OBJECTIVE: To validate the Japanese version of the Oral Health Impact Profile (OHIP-J) for use among young and middle-aged adults. Evaluating the criterion validity was particularly important in this study. METHOD: The original Oral Health Impact Profile (OHIP) was translated into Japanese. Data from 6,079 subjects aged 20-59 were collected by means of a self-administered questionnaire and the oral condition records of a sample of workers. The survey involved items for the OHIP-J and self-rated oral health, denture wearing, number of missing teeth, work type, occupational rank, gender, and age. We adopted a self-rated oral health and number of missing teeth as validity criteria for this analysis. RESULTS: Using multiple linear regression analysis, the adjusted total OHIP-J scores for respondents who rated their oral health as poor were higher than those who did not (46.6 vs. 27.6; p<0.001). The variable of missing teeth was significantly associated with the OHIP-J total and subscale scores independent of gender, age and denture wearing (p<0.001). CONCLUSIONS: These findings suggest that the OHIP-J is suitable for assessing the oral health-related quality of life of young and middle-aged adults in Japan.