School Achievement and Oral Health Behaviour Among Adolescents in Finland: A National Survey.

PURPOSE: We examined oral health behaviour and its association with school achievement among Finnish adolescents. MATERIALS AND METHODS: This study is part of the Finnish national School Health Promotion study (SHP). The study population comprised a representative sample of Finnish 15-year-olds (N = 45,877). A questionnaire inquired about the respondents' school achievements and health habits (toothbrushing, smoking), background factors (age, gender, school type, family structure), and their parents' background factors (education, smoking). Chi-square tests and logistic regression models were used in the statistical analyses. RESULTS: Better school achievements were associated with better oral health behaviour: 73.1% of students with the highest mean grades (9-10) brushed their teeth twice daily, compared to 33.8% of those with the lowest mean grade (6.9 or less). The lowest mean grade was associated with brushing less than twice daily, especially among boys (odds ratios (OR) = 4.1; 95% CI 3.6-4.7) when compared to those with the highest mean grade, but also among girls (OR = 2.3; 95% CI 2.1-2.7). Smoking among boys was associated with poor oral hygiene (OR = 1.3; 95% CI 1.2-1.4). CONCLUSION: School success is strongly associated with oral health behaviour among adolescents. Preventive treatment should be targeted especially at boys with poor school achievement and smoking behaviour.

Physical activity, BMI and oral health behaviour among adolescents: Finnish School Health Promotion Study.

BACKGROUND: To assess associations between oral health behaviour and physical activity and related factors among adolescents. METHODS: The study population (n = 76 529) consisted of a representative sample of 16- to 18-year-old Finnish adolescents (boys: 37 211, girls: 39 318). An anonymous, confidential and voluntary classroom-administered questionnaire included questions about tooth brushing frequency, physical activity, BMI and eating habits. Moderate-to-vigorous physical activity (MVPA) was used to assess the adolescents' physical activity. The chi-square test and multiple binary logistic regression were used for statistical analyses. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) were calculated for MVPA, BMI, breakfast, smoking and socioeconomic factors as parents' education and school type. RESULTS: The prevalence of twice daily tooth brushing was highest among adolescents reporting 4 hours or more of MVPA (51-77%). Obese and smoking adolescents exercised less often than normal weighted and non-smokers. Girls brushed their teeth twice daily significantly more often than boys (P < 0.001), and high-school students brushed their teeth significantly more often than vocational school students (P < 0.001). Logistic regression models showed that obesity (OR = 2.14, 95% CI 1.92-2.37) and irregular breakfast eating (OR = 2.35, 95% CI 2.19-2.52) among boys, and obesity (OR = 2.81, 95% CI 2.48-3.17), physical inactivity (OR = 1.89, 95% CI 1.78-2.00) and irregular breakfast eating (OR = 1.91, 95% CI 1.79-2.04) among girls were strong predictors for poor tooth brushing. CONCLUSIONS: Physically active adolescents had better oral health behaviour than less active adolescents. Obesity and smoking were associated with infrequent tooth brushing.

Validity of self-reported number of teeth in middle-aged Finnish adults: the Northern Finland Birth Cohort Study 1966.

BACKGROUND: We examined the validity of self-reported number of teeth in middle-aged adults by using representative cohort data to compare corresponding self-reported and clinical values. METHODS: This validity study is part of the representative 46-year-old follow-up of the Northern Finland Birth Cohort 1966 (NFBC1966) Study. Mailed questionnaires (n = 5950) requested information on self-reported number of teeth and background variables (education, tooth brushing and smoking), while clinical oral health examinations (n = 1891) assessed the number of teeth (the 'gold standard'). The main analyses compared the self-reported and clinical values for the number of teeth in 1669 participants. Scatterplot and Bland-Altman plot served for visual analyses, and alternative correlation coefficients (Pearson, Spearman, intraclass) for numerical comparisons separately for men and women, with stratification according to background variables. RESULTS: The clinical assessment revealed that the mean value for the number of teeth was 27.46 (SD = 2.38), while the corresponding value based on self-reported information was 27.48 (SD = 2.78). According to the Bland-Altman plot, the mean difference between the clinical and self-reported values was - 0.02 (95% limits of agreement, LoA: - 3.37 to 3.32). The observed ranges of intraclass correlation coefficients (ICC) among men and women were 0.72 to 0.95 and 0.72 to 0.85, respectively, depending on the background variables. CONCLUSIONS: Self-reported number of teeth in middle-aged Finnish adults agreed closely with the corresponding clinical measure.

Impaired glucose metabolism is associated with tooth loss in middle-aged adults: The Northern Finland Birth Cohort Study 1966.

AIM: We investigated the association of impaired glucose metabolism with tooth loss in adults in the Northern Finland Birth Cohort Study 1966 (NFBC1966). METHODS: We examined 4394 participants from the 46-year follow-up of the NFBC1966. Self-reported number of teeth as well as insulin and glucose values, taken during a standard oral glucose tolerance test (OGTT), served as the primary study variables. A multinomial logistic regression model served to analyse (unadjusted, smoking-adjusted and fully adjusted) the association between number of teeth (0-24, 25-27, 28-32) and glucose metabolism in women and men. RESULTS: Among women, type 2 diabetes - whether previously known or detected during screening - pointed to a higher likelihood of 0-24 teeth (fully adjusted OR = 2.99, 95%CI = 1.54-5.80) and 25-27 teeth (OR = 1.91, 95%CI = 1.18-3.08) than did normal glucose tolerance. Similarly, impaired fasting glucose and impaired glucose tolerance together indicated a higher likelihood of 0-24 teeth (OR = 1.71, 95%CI = 1.09-2.69) than did normal glucose tolerance. A similar, statistically non-significant, pattern emerged among men. Number of teeth associated with OGTT insulin and glucose curves as well as with the Matsuda index in both women and men. CONCLUSIONS: Tooth loss strongly associated with impaired glucose metabolism in middle-aged Finnish women.

Long-term effects of smoking on tooth loss after cessation among middle-aged Finnish adults: the Northern Finland Birth Cohort 1966 Study.

BACKGROUND: Despite smoking cessation efforts, cigarette smoking remains a serious general and oral health problem. We aimed to investigate the putative benefits of smoking cessation on dentition and to analyse whether the time elapsed since smoking cessation associated positively with the remaining number of teeth. METHODS: This cross-sectional study analyses data from the 46-year follow-up of the Northern Finland Birth Cohort Study 1966 (NFBC1966). A total of 5 540 subjects participated in this cross-sectional study, which utilises both clinical dental examinations and mailed questionnaires. We used the following information on smoking: status (current, former, never), years of smoking (current, former) and years elapsed since smoking cessation (former). Self-reported and clinically measured number of teeth (including third molars) served as alternative outcomes. We used binary logistic regression models to analyse the dichotomised number of teeth ('0-27', '28-32') and then calculated unadjusted and adjusted odds ratios (OR) with 95 % confidence intervals (CI) for the smoking variables (never smoker as the reference). Gender, education, tooth brushing frequency, diabetes and alcohol use served as confounders for the adjusted models. RESULTS: Ten years or more of smoking associated with tooth loss; this effect was the strongest among men who reported having an ongoing smoking habit (self-reported outcome: adjusted OR = 1.74, CI = 1.40-2.16) and the weakest among women classified as former smokers (self-reported outcome: adjusted OR = 1.27, CI = 1.00-1.62). CONCLUSIONS: This study shows that smoking has long-term effects on tooth loss even after cessation. The findings support smoking cessation efforts to reduce oral health risks.

Association between smoking intensity and duration and tooth loss among Finnish middle-aged adults: The Northern Finland Birth Cohort 1966 Project.

BACKGROUND: Smoking is a risk factor for oral diseases and tooth loss. Our aim was to analyze the association between smoking intensity and duration and tooth loss among middle-aged Finnish adults who have enjoyed access to subsidized dental care since childhood. METHODS: This study was based on the Northern Finland Birth Cohort 1966 (NFBC1966) Project, a representative sample of Finnish 46-year-olds. Altogether 1946 46-year-olds participated in a survey and comprehensive clinical oral examinations. We measured smoking exposure in pack-years (intensity) and years of smoking (duration) combined with recent smoking status (current, former, occasional or never). We used negative binomial regression models to estimate the unadjusted and adjusted relative risks (RR) with corresponding 95 % confidence intervals (CI) for tooth loss as an outcome. Gender, education, tooth brushing frequency, dental plaque, diabetes and alcohol use served as explanatory variables for the adjusted models. RESULTS: Smoking intensity associated with tooth loss in an exposure-dependent manner: those with a high number of pack-years had a significantly greater probability of tooth loss than never smokers: 11-20 pack-years (RR = 1.55, 95 % CI = 1.15-2.08) and 21 or more pack-years (RR = 1.78, 95 % CI = 1.36-2.33). Smoking duration also associated with tooth loss: those who had smoked for several years had a significantly higher probability of tooth loss than never smokers: 21-30 years of smoking (RR = 1.66, 95 % CI = 1.29-2.12) and 31 or more years of smoking (RR = 1.72, 95 % CI = 1.20-2.45). CONCLUSIONS: We found a clear intensity- and duration-dependent relation between smoking and tooth loss among adults with access to subsidized dental care and in good oral health.