A Case-Control Study of Fluoridation and Osteosarcoma.

Public health policy decisions in the United States have resulted in 62.4% of the population having access to fluoridated water. The purpose of this study was to examine the association between community water fluoridation and osteosarcoma. A secondary data analysis was performed with data collected from 2 separate but linked studies. Patients for phase 1 and phase 2 were selected from US hospitals via a matched case-control study design. For both phases, cases included patients diagnosed with osteosarcoma, and controls were patients diagnosed with other bone tumors or nonneoplastic conditions. In phase 1, cases (n = 209) and controls (n = 440) were patients of record in the participating orthopedic departments from 1989 to 1993. In phase 2, cases (n = 108) and controls (n = 296) were incident patients who were identified and treated by orthopedic physicians from 1994 to 2000. This analysis included all patients who met eligibility criteria on whom we had complete data on covariates, exposures, and outcome. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% CIs for the association of community water fluoridation with osteosarcoma. A modestly significant interaction existed between fluoridation living status and bottled water use (P = 0.047). The adjusted OR for osteosarcoma and ever having lived in a fluoridated area for nonbottled water drinkers was 0.51 (95% CI, 0.31 to 0.84; P = 0.008). In the same comparison, the adjusted OR for bottled water drinkers was 1.86 (95% CI, 0.54 to 6.41; P = 0.326). Findings from this study demonstrated that community water fluoridation is not associated with an increased risk for osteosarcoma.

An assessment of bone fluoride and osteosarcoma.

The association between fluoride and risk for osteosarcoma is controversial. The purpose of this study was to determine if bone fluoride levels are higher in individuals with osteosarcoma. Incident cases of osteosarcoma (N = 137) and tumor controls (N = 51) were identified by orthopedic physicians, and segments of tumor-adjacent bone and iliac crest bone were analyzed for fluoride content. Logistic regression adjusted for age and sex and potential confounders of osteosarcoma was used to estimate odds ratios (OR) and 95% confidence intervals (CI). There was no significant difference in bone fluoride levels between cases and controls. The OR adjusted for age, gender, and a history of broken bones was 1.33 (95% CI: 0.56-3.15). No significant association between bone fluoride levels and osteosarcoma risk was detected in our case-control study, based on controls with other tumor diagnoses.

Exploring opportunities for collaboration between the corporate sector and the dental education community.

The ultimate purpose of both dental industry and dental education is to improve the oral health of the public. This report provides background information on the different roles and objectives of the dental industry and dental education communities, the different operating environment of each sector and also areas of common interest where collaboration will be of mutual benefit. The report addresses five areas for potential collaboration between the dental industry and the dental education communities: 1. Contribution to joint activities. 2. Effectiveness and efficiency. 3. Workforce needs. 4. Middle- and low-income countries. 5. The future of International Federation of Dental Educators and Associations (IFDEA). The traditional areas of support and their limitations that have been provided by industry are outlined in the report and some new approaches for collaboration are considered. Industry-based research has been an important factor in developing new products and technologies and in promoting oral health. However there is a need to facilitate the introduction of these developments at an early stage in the education process. Industry has to operate in an efficient manner to remain competitive and maximise its returns and therefore survive. The academic sector operates in a different environment and under different governance structures; although some trends are noted towards adoption of greater efficiency and financial accountability similar to industry. Opportunities to jointly develop best business practices should be explored. Industry has responded well to the oral health needs of the public through the development of new products and technologies. The education community needs to respond in a similar way by examining different healthcare delivery models worldwide and developing programmes to train members of the dental team to cater for future needs and demands of communities in different regions of the world. The reputation of industry-based scientists and clinicians is high, and their role in contributing to the dental education process in practical ways needs to be explored and further developed. Closer relationships between industry scientists and faculty and students could assist industrys need and desire to develop new technologies for the broader dental care system. The corporate sector can play a key role in the future success of IFDEA by providing support and expertise in developing areas such as regional leadership institutes, a Global Faculty and Network and in collaborating in developing continuing education programmes as well as involvement in its governance. Thirteen recommendations are made in the report. These are considered to be important initial steps in developing the already strong relationship between the education and corporate sectors. Partnership and collaborating more effectively along the lines suggested should, almost certainly, generate mutually beneficial outcomes, whilst serving over the long term to elevate the publics oral health status on a global basis.

Environmental and heritable factors in the etiology of oral diseases--a population-based study of Swedish twins.

A population-based twin study is a useful design for quantification of the effects of genes and environmental factors in disease etiology. We used data from 10,000 Swedish twin pairs to quantify genetic and environmental contributions to tooth loss and periodontal health. Oral health information was obtained from telephone interviews. Structural equation models measured the relative importance of genetic and environmental factors. Genetic factors contributed to 14% of variation in tooth loss among women, and 39% among men. Non-shared environmental factors accounted for one-quarter of risk; environmental factors shared by twins comprised the remainder. Heritability estimates of periodontal disease were 39% and 33% for women and men, respectively, while non-shared environmental factors accounted for the remaining variation. Heritability for both conditions varied as a function of age and smoking status. Analysis of data from this large, population-based study demonstrates a moderate role of genetic factors in oral diseases, and suggests potential gene-environment interactions.

Frailty approach for the analysis of clustered failure time observations in dental research.

Because dental implant failure patterns tend to cluster within subjects, we hypothesized that the risk of implant failure varies among subjects. To address this hypothesis in the setting of clustered, correlated observations, we considered a retrospective cohort study where we identified a cohort having at least one implant placed. The cohort was composed of 677 patients who had 2349 implants placed. To test the hypothesis, we applied an innovative analytic method, i.e., the Cox proportional hazards model with frailty, to account for correlation within subjects and the heterogeneity of risk, i.e., frailty, among subjects for implant failure. Consistent with our hypothesis, risk for implant failure among subjects varied to a statistically significantly degree (p=0.041). In addition, the risk for implant failure is significantly associated with several factors, including tobacco use, implant length, immediate implant placement, staging, well size, and proximity of adjacent implants or teeth.

Risk factors for dental implant failure: a strategy for the analysis of clustered failure-time observations.

This study's objective was to identify, in a statistically valid and efficient manner, the risk factors associated with dental implant failure. We hypothesize that factors exist which can be modified by clinicians to enhance outcome. A retrospective cohort study design was used. Cohort members had >or= one implant placed. Risk factors were classified as demographic, health status, implant-, anatomic-, or prosthetic-specific, and reconstructive variables. The outcome variable was implant failure. The cohort was composed of 677 patients who had 2349 implants placed. Based on the adjusted multivariate model, factors associated with implant failure were tobacco use, implant length, staging, well size, and immediate implants (p

Factors associated with delay in the diagnosis of oral cancer.

Early detection and treatment improve the prognosis for oral cancer. Delays from the onset of symptoms to clinical diagnosis are common. Our aim is to identify factors associated with this delay. Between 1995 and 1998, we interviewed 105 consecutive patients with histologically confirmed oral cancer in Greece. If 21 or more days elapsed from the time the patient noticed major symptoms to a definitive diagnosis, we called it a delay (52% of cases). We used logistic and linear regression to estimate odds ratios of delayed diagnosis and to identify correlates of length of delay, respectively. Former smokers had a 4.3 times greater risk of delayed diagnosis compared with current smokers (95% confidence interval: 1.1-17.1). The length of delay was greater among single patients, non-smokers, or those with stage IV tumors. Clinicians should be advised that delay in the diagnosis of oral cancer occurs frequently, even in individuals who do not smoke heavily.

Smoking and alcohol in the etiology of oral cancer: gender-specific risk profiles in the south of Greece.

Oral and pharyngeal cancer (OC) mortality is very low in Greece, especially among men, compared to other European countries. We conducted a case-control study of OC in Athens, and obtained information on tobacco, alcohol use and other potential risk factors and confounding variables for 110 incident cases and 115 hospital-based controls. We used multivariate logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Tobacco smoking (pack years, P(trend)=0.01) and alcohol use (drinks/week, P(trend)=0.07) were independent risk factors, with a multiplicative effect for combined exposures (OR, 8.3; 95% CI, 2.4-29.1, for >28 alcohol drinks/week and >50 pack years of cigarette smoking). The type of alcoholic beverage also seemed important: drinking ouzo and tsipouro (liquors of high ethanol concentration) was associated with greater increased OC risk than drinking comparable amounts of wine, beer or dark spirits. While alcohol drinking is more common for male cases versus controls, few men reported regularly consuming large quantities of ethanol associated with highest risk of OC in other studies. This may partially explain the low rates of male OC mortality in Greece. Among the 38% of our cases who were women, however, neither smoking nor alcohol drinking frequencies were significantly elevated compared to controls, and so the etiology of OC risk in females requires further investigation.

Patients' expectations for oral health care in the 21st century.

BACKGROUND: This article examines trends in patient demographics and dental disease patterns. Data suggest the patient expectations about oral health are increasing, as is their knowledge of oral health services. CLINICAL IMPLICATIONS: Changing patient demographics and technological advances will lead to higher patient expectations and greater demands for oral health care in the 21st century than they had been during most of the 20th century.

Possible explanations for the tooth loss and cardiovascular disease relationship.

Several studies have shown relationships between periodontal disease and cardiovascular disease (CVD). A few studies have also shown that tooth loss may be associated with increased risk of coronary heart disease and stroke. We have reviewed the relevant literature to assess possible explanations for the reported associations between tooth loss and CVD. In particular, we considered whether the reported association between tooth loss and CVD could be explained by antecedent periodontal disease, antecedent caries, the extraction process, dietary changes following tooth loss, or confounding or bias from other sources. Since access to care and attitudes to health care may influence the decision to extract teeth, as well as cardiovascular disease risk, one needs to be cautious about confounding from behaviorally related factors. Available evidence suggests that further studies are needed to rule out that confounding is a possible explanation for the tooth loss and CVD relationship, that prior periodontal disease may not completely explain the tooth loss-CVD relationship, and that the role of diet needs to be further explored

Update on student debt: trends and possible consequences.

This paper is an update on the issue of dental student debt and provides additional data and an exploration of continued trends which were outlined by Douglass and Fein in the 1995 IOM study of The Future of Dental Education. Dental school tuitions have continued to increase at rates at or above the consumer price index. These tuition bills are increasingly being met by debt financing on the part of the students. These trends are described and then related to recent data on the future plans of dental school seniors. The second part of the paper will provide new updated date on dentists' incomes and analyze the trend in dental fees versus the consumer price index. The final section provides a summary of pay back mechanisms currently being offered to students.

Poor oral health and coronary heart disease.

A few recent studies have shown associations between poor oral health and coronary heart disease (CHD). The objective of this study was to examine the incidence of CHD in relation to number of teeth present and periodontal disease, and to explore potential mediators of this association, in a prospective cohort study. This study is a part of the ongoing Health Professionals Follow-Up Study (HPFS). Participants included a US national sample of 44,119 male health professionals (58% of whom were dentists), from 40 to 75 years of age, who reported no diagnosed CHD, cancer, or diabetes at baseline. We recorded 757 incident cases of CHD, including fatal and non-fatal myocardial infarction and sudden death, in six years of follow-up. Among men who reported pre-existing periodontal disease, those with 10 or fewer teeth were at increased risk of CHD compared with men with 25 or more teeth (relative risk = 1.67; 95% confidence interval, 1.03 to 2.71), after adjustment for standard CHD risk factors. Among men without pre-existing periodontal disease, no relationship was found (relative risk = 1.11; 95% confidence interval, 0.74 to 1.68). The associations were only slightly attenuated after we controlled for dietary factors. No overall associations were found between periodontal disease and coronary heart disease. Tooth loss may be associated with increased risk of CHD, primarily among those with a positive periodontal disease history; diet was only a small mediator of this association.

The impact of edentulousness on food and nutrient intake.

The authors collected dietary intake data about the food and nutrient intake of 49,501 male health professionals. Edentulous participants consumed fewer vegetables, less fiber and carotene, and more cholesterol, saturated fat and calories than participants with 25 or more teeth. These factors could increase the risks of cancer and cardiovascular disease. Mean differences in intake ranged from 2 to 13 percent, independent of age, smoking, exercise and profession. Longitudinal analyses suggest that tooth loss may lead to detrimental changes in diet.

Cost effectiveness of periodontal services.

This paper presents the combined use of decision trees and cost-effectiveness analysis to determine on which patients new diagnostic tests can be useful, and whether they can change the dentist's decision to provide different services and thus improve patient outcomes in 5 different categories of patients. A decision tree is constructed in which the primary decision branches are "test" and "no test". The treatment and outcome branches in the test branch are affected by the results of the test which is then either negative or positive. In contrast, the treatment and outcome branches in the no-test branch represent pathways for patient therapy when the new (or additional) test is not used. Results show that even with excellent test efficacy parameters (sensitivity 0.87 and specificity 0.84) it is not cost effective to use a diagnostic test in the general population or for adults under age 45 years. However for adults > 45 years, patients referred to a periodontist, and patients with a history of periodontal disease, the test would change treatment decisions and improve patient care outcomes.

Consequences of success: do more teeth translate into more disease and utilization?

OBJECTIVES: Increased tooth retention coupled with increased numbers of older adults means that the actual number of teeth at risk to dental disease will increase sharply. Whether this increase in the number of teeth will translate into more disease and utilization in unknown. The purpose of this study was to test this "more teeth, therefore more dental disease" theory using cross-sectional data. METHODS: In-home personal interview and oral examination data were obtained on a probability sample of elders aged 70 years and older living in the six New England states using the Medicare beneficiary list as a sampling frame. Data on dental utilization, number of teeth, dental caries, and periodontal disease were included in the current analysis. RESULTS: Analysis of variance on subjects with 1-10 (Group 1), 11-24 (Group 2), and 25-32 (Group 3) teeth show that the extent of bleeding on probing, pocket depth, and loss of attachment all increase as numbers of teeth increase. Similarly, a greater number of restored coronal and root surfaces were found in Group 3 relative to the other two groups. Mean numbers of decayed and filled coronal surfaces were 8.4 in Group 1.33.0 in Group 2, and 50.3 in Group 3. In contrast, unrestored coronal and root surface were significantly higher in Group 1 (mean root DS = 1.3) than Group 3 (mean root DS = 0.3). Utilization patterns of those with successful aging dentitions (Group 3) show that they are visiting dentists more frequently than the compromised group (Group 1). CONCLUSIONS: These cross-sectional data obtained from a probability sample of New England elders show that subjects who retained higher numbers of teeth have more periodontal disease and dental caries experience, and visit the dentist more frequently.

Validity of a self-reported periodontal disease measure.

OBJECTIVES: The purpose of this study was to determine the validity of a self-reported periodontal disease measure for use in the Health Professionals Follow-up Study. METHODS: Participating dentists responded to the question "Have you had periodontal disease with bone loss?" Radiographs obtained from 140 participants were evaluated for bone loss at 32 posterior sites and used as the standard. A site was positive if it had bone loss > 2 mm and/or complete loss of crestal lamina dura. To avoid falsely classifying participants as positive, three blinded examiners independently evaluated each participant's radiographs. An a priori decision rule was used to classify a participant positive if all examiners independently assessed the same two or more sites positive. RESULTS: The validity of the self-reported measure was good among dentists, with positive and negative predictive values of 0.76 and 0.74, respectively. Among nondentists, the self-reported measure showed discriminatory power by confirming associations with known risk factors such as age and smoking. CONCLUSIONS: Dentists have a good perception of their periodontal status, and there is reasonable consensus among dentists regarding the threshold for defining periodontal disease. Self-reported measures might have potential for use in studies of other populations with substantial cost reduction, and deserve further evaluation.

Dispelling the myth that 50 percent of U.S. schoolchildren have never had a cavity.

The erroneous claim that 50 percent of U.S. schoolchildren have never had a cavity has taken on the virtues of truth through frequent and widespread restatement. The 50-percent caries-free statement is an excessively optimistic misrepresentation by the media of the 1986-87 survey of oral health among schoolchildren by the National Institute of Dental Research because it only tells part of the story--it ignores dental disease in the primary dentition. This article documents that numerous public policy papers reflect failure to consider primary tooth caries data. Consequently, a significant disease burden has been overlooked. The article reviews the persistent underreporting of children's caries experience in policy documents and the dental literature, and reviews additional epidemiologic studies of caries reported in U.S. dental literature since 1985. Dental caries remains the single most common disease of childhood that is not self-limiting or amenable to a course of antibiotics. The popular statement that half of U.S. schoolchildren have never experienced tooth decay fails profoundly to reflect the extremity and severity of this still highly prevalent condition of childhood. At a time of extreme pressure on the Medicaid Early and Periodic Screening, Diagnosis, and Treatment budget this uncritically held belief is leading to inappropriate policy and funding decisions that can put the health of children at risk.