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Biomedical subjects

C W Douglass

Publications and source records attributed to C W Douglass.

At least 19 recordsLinked to original sources
PubMed2005

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.

Analysis of Variance↗
PubMed2005

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.

Adult↗
PubMed2002

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 <or= 0.05). In the setting of correlated survival observations, we recommend adjusting for the correlation of the observations to provide statistically valid and efficient results. Three of the identified factors--tobacco use, immediate implants, and implant staging--potentially may be modified to enhance implant survival.

Age Factors↗
PubMed2002

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.

Adult↗
PubMed2001

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.

Adult↗
PubMed2000

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.

Adult↗
PubMed1998

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

Attitude to Health↗
PubMed1997

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.

Education, Dental↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Aged↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1996

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.

Adult↗
PubMed1994

Epidemiologic study of sound surface trends in a 10-year longitudinal study.

Longitudinal data of 589 men aged 30-65 yr, each followed for 10 yr, were analyzed to identify variables which may be associated with healthy tooth surface loss. A longitudinal linear growth curve model was used. As expected, older cohorts tended to have fewer sound surfaces (P < 0.02), but they also tended to have greater rates of sound surface loss (P < 0.01). Age, bone loss, number of teeth at baseline, gingivitis, pocket depth and calculus were individually correlated (P < 0.05) with the rate of sound surface loss. The number of filled or diseased surfaces at baseline was also marginally correlated (P < 0.06) with rate of sound surface loss.

Adult↗
PubMed1994

The distribution of root caries in community-dwelling elders in New England.

An in-home examination of a probability sample of elders aged 70 and older living in the six New England states was conducted to estimate the prevalence and extent of root caries. Oral examinations were conducted by the visual-tactile method using a portable lamp, explorer, and a mouth mirror. Fifty-two percent of the study participants showed root caries experience and 22 percent had untreated root caries. In contrast to previous studies, this analysis showed that buccal root surfaces were no more likely than proximal surfaces to be affected by root caries. Logistic regression analysis showed that gingival recession and number of teeth were positively associated with root caries, while better oral hygiene maintenance and regular dental visits were negatively associated with root caries lesions (all factors: P < .05). The prevalence of root caries was found to increase with higher numbers of teeth except for a minority subgroup--i.e., those who retained 25 or more teeth. This study provides much-needed data on prevalence and extent of root caries in a probability sample of the oldest old in an entire region of the United States.

Age Distribution↗