Measures of dental disease occurrence

Estimating the prevalence of untreated caries in permanent teeth from the DMF index and lifetime caries prevalence

AIM

To derive formulas to estimate the prevalence of untreated dental caries in permanent teeth based on the DMF index and lifetime caries prevalence.

METHODS

Data from participants, aged 5 years or older, in the National Health and Nutrition Examination Survey 2011-2016 were analyzed. Dental caries was assessed at surface level with the Radike criteria, which matches the case definition of the Global Burden of Disease study. Participants' data were aggregated into 438 groups, based on survey strata and 5-year age brackets, to produce population estimates for the prevalence of untreated caries (DT > 0), DMFT, DMFS, DT, DS, and lifetime caries prevalence (DMFT>0). Conversion formulas were derived using fractional polynomials to characterize the association of each caries indicator with the prevalence of untreated caries.

RESULTS

The mean prevalence of untreated caries was 23.5 percent (SD: 12.9 percent, range: 1.0-72.3 percent). After adjustment for age, the prevalence of untreated caries was correlated with DMFT (r = 0.23), DMFS (r = 0.25), DT (r = 0.74), DS (r = 0.65) and lifetime caries prevalence (r = 0.18). Using fractional polynomial models adjusted for categorical age, the prevalence of untreated caries at population level could be estimated from DMFT with power 1 (linear form), DMFS with power 0.5, DT with power 0.5, DS with powers (0.5; 1) and lifetime caries prevalence with power 1.

CONCLUSION

The prevalence of untreated caries in permanent teeth can be estimated from the DMF index and lifetime caries prevalence. These conversion formulas can facilitate the inclusion of more studies in estimation of the global burden of untreated caries in permanent teeth.

Vitamin D and dental caries in controlled clinical trials: systematic review and meta-analysis

Vitamin D has been used to prevent and treat dental caries. The objective of this study was to conduct a systematic review of controlled clinical trials (CCTs) assessing the impact of vitamin D on dental caries prevention. Random-effects and meta-regression models were used to evaluate overall and subgroup-specific relative-rate estimates. Twenty-four CCTs encompassing 2,827 children met the inclusion criteria. Twenty-two of the 24 CCTs predated modern clinical trial design, some of which nonetheless reported characteristics such as pseudo-randomization (n = 2), blinding (n = 4), or use of placebos (n = 8). The relative-rate estimates of the 24 CCTs exhibited significant heterogeneity (P < 0.0001), and there was evidence of significant publication bias (P < 0.001). The pooled relative-rate estimate of supplemental vitamin D was 0.53 (95% CI, 0.43-0.65). No robust differences were identified between the caries-preventive effects of vitamin D(2) , vitamin D(3) , and ultraviolet radiation (Prob > F = 0.22). The analysis of CCT data identified vitamin D as a promising caries-preventive agent, leading to a low-certainty conclusion that vitamin D may reduce the incidence of caries.

Methodological issues in longitudinal epidemiologic studies of dental caries

As longitudinal epidemiologic studies of dental caries address increasingly complex research questions, approaches to analysis of data from those studies have become more sophisticated. This review examines methods available for analyzing and reporting data from such studies. Traditional analytic methods utilize the DMFS increment as the outcome measure in longitudinal studies of caries. However, two other outcome measures may be needed to address some research issues: cumulative incidence, which quantifies caries risk; and incidence density, which quantifies caries rate. Four major analytic decisions have to be addressed when computing DMFS increment: examiner misclassification ("reversals"), teeth lost due to caries, findings from more than two examinations, and multiple events such as caries initiation and progression. We present a uniform approach for enumerating caries events that permits the same analytic decisions made in calculating DMFS increment to be applied to cumulative incidence and incidence density calculations. In view of the variety of analytic decisions that must be made when enumerating events in longitudinal studies of caries, authors should specify how all potential changes in caries status were handled. Furthermore, if a study uses more than one outcome measure, the same decisions for enumerating events should be used when computing those measures.

Forty-five-year tooth survival probabilities among men in Oslo, Norway

Changes in tooth survival probabilities over a person's lifetime have remained largely unexplored. The goal of this study was to evaluate changes in the 45-year tooth survival probabilities in a cohort of 565 Norwegian males who were examined in 1969 as young adults, and followed up into mid-life (examination years and sample sizes (n): 1971 (n = 381), 1973 (n = 292), 1975 (n = 245), 1981 (n = 228), 1988 (n = 202), and 1995 (n = 223). The results indicated that the tooth survival probabilities varied considerably both (i) among teeth within individuals, and (ii) over time. The 45-year survival probabilities for the 28 teeth fell into the following ranges: larger than 95% for incisors and cuspids; between 84% and 92% for premolars; and between 59% and 96% for molars. Over the first 4 post-eruptive decades, the tooth mortality risks (excluding orthodontic extractions) were: 1st decade, 2.0% (from 1.7 to 2.4%); 2nd decade, 0.2% (from 0.1 to 0.4%); 3rd decade, 0.6% (from 0.4 to 0.8%); and 4th decade, 1.1% (from 0.8 to 1.5%). The tooth mortality risks in the 2nd, 3rd, and 4th decades were probably somewhat underestimated (due to dropout bias), suggesting that the true underlying tooth mortality hazard function may have been V-shaped. The conclusions were that the tooth mortality hazard during the first 4 post-eruptive decades was bathtub-shaped and that it varied considerably among teeth within individuals.

Outcome measures in split mouth caries trials and their statistical evaluation

The split mouth study design in trials of fissure sealants and restorative materials neatly controls for confounding by many of the variables associated with poor retention of sealants and occurrence of dental caries. Traditionally, the outcome measures used in split mouth trials have been material retention, (per cent) effectiveness and net gain. A survey of the literature revealed that a large proportion of split mouth studies report no statistical evaluation of outcome measures. In those studies in which statistical evaluation had been conducted, McNemar's X2 was the test most frequently used. This statistic is appropriate for comparing differences between "success" and "failure" tooth pairs (or "positives" and "negatives" in split mouth terminology) but it cannot evaluate directly effectiveness and net gain. The distributions of effectiveness and net gain are different and it would be desirable to estimate confidence intervals for them. In this paper, we consider these statistics, suggest methods by which confidence intervals may be calculated, and provide examples of the calculations. We demonstrate the close relationship between effectiveness (as used in split mouth trials) and relative effect and relative risk (as used in general epidemiological analysis) and recommend that relative risk should be the preferred outcome measure for split mouth trials. Whatever outcome measure is chosen in split mouth trials should always be subjected to statistical evaluation, preferably by the calculation of confidence intervals.

Oral health status of a long-term-care, veteran population

The Department of Veterans Affairs (VA) operates the largest, integrated health care system in the United States of America. The projected need for long-term-care in the VA health care system parallels an expected increase in need for care in the United States, but precedes the need for care in the general population by 25-30 yr. The VA's Office of Dentistry, in an effort to estimate the resource requirements of this swelling group of veterans, initiated in 1986-7 an oral health survey of long-term care patients. The overall goals were to describe the oral health status of VA nursing home care units (NHCU) residents and to develop a methodology for estimating future dental health services utilization. This study describes the oral health status of the study population. Demographic and oral health data were collected for 650 long-term care residents of six VA NHCUs between October 1986 and July 1987. Data were collected on sociodemographic status, medical history, dental caries, periodontal diseases, oral soft tissue pathology, and the presence of dental prostheses. Caries and periodontal disease were evaluated using the United States National Institute of Dental Research Survey of Employed Adults and Seniors protocols. The oral health status of the population is described using DMF and ESI indices, the prevalence of oral lesions, levels of tooth loss, oral hygiene scores, and the status of existing dentures. Findings show moderate levels of untreated dental caries and periodontal disease and significant tooth loss which increased with age. A need for preventive therapy, restorative dentistry, conservative periodontal therapy, and prosthodontic care was evident.(ABSTRACT TRUNCATED AT 250 WORDS)