Option-4 algorithm for third generation disc probe: agreement of selected site-specific relative attachment level measurements and detection of longitudinal site-specific attachment level change

Modelling changes in clinical attachment loss to classify periodontal disease progression

AIM

The goal of this study was to identify progressing periodontal sites by applying linear mixed models (LMM) to longitudinal measurements of clinical attachment loss (CAL).

METHODS

Ninety-three periodontally healthy and 236 periodontitis subjects had their CAL measured bi-monthly for 12 months. The proportions of sites demonstrating increases in CAL from baseline above specified thresholds were calculated for each visit. The proportions of sites reversing from the progressing state were also computed. LMM were fitted for each tooth site and the predicted CAL levels used to categorize sites regarding progression or regression. The threshold for progression was established based on the model-estimated error in predictions.

RESULTS

Over 12 months, 21.2%, 2.8% and 0.3% of sites progressed, according to thresholds of 1, 2 and 3 mm of CAL increase. However, on average, 42.0%, 64.4% and 77.7% of progressing sites for the different thresholds reversed in subsequent visits. Conversely, 97.1%, 76.9% and 23.1% of sites classified as progressing using LMM had observed CAL increases above 1, 2 and 3 mm after 12 months, whereas mean rates of reversal were 10.6%, 30.2% and 53.0% respectively.

CONCLUSION

LMM accounted for several sources of error in longitudinal CAL measurement, providing an improved method for classifying progressing sites.

Analytical epidemiology of periodontitis

AIMS

To review the literature related to the analytical epidemiology of periodontitis generated over the past decade. This review does not deal with descriptive epidemiologic studies of the prevalence, extent and severity of periodontitis with respect to global geography, but focuses exclusively on analytical epidemiology issues, including the challenges posed by the use of different case definitions across studies, current theories and models of disease progression, and risk factors associated with the onset and progression of periodontitis.

METHODS

Relevant publications in the English language were identified after Medline and PubMed database searches.

FINDINGS AND CONCLUSIONS

There is a conspicuous lack of uniformity in the definition of periodontitis used in epidemiologic studies, and findings from different research groups are not readily interpretable. There is a lack of studies that specifically address the distinction between factors responsible for the onset of periodontitis versus those affecting its progression. Colonization by specific bacteria at high levels, smoking, and poorly controlled diabetes have been established as risk factors for periodontitis, while a number of putative factors, including specific gene polymorphisms, have been identified in association studies. There is a clear need for longitudinal prospective studies that address hypotheses emerging from the cross-sectional data and include established risk factors as covariates along with new exposures of interest. Intervention studies, fulfilling the "targeting" step of the risk assessment process, are particularly warranted. Obvious candidates in this context are studies of the efficacy of elimination of specific bacterial species and of smoking cessation interventions as an alternative to the traditional broad anti-plaque approach in the prevention and control of periodontitis. Ideally, such studies should have a randomized-controlled trial design.

Improvements in methods of periodontal probing: comparison of relative attachment level data selected by outlier reduction protocols from Florida disc probe measurements

OBJECTIVES

To compare relative attachment level data (RAL) selected by the Option-4 algorithm (O-4), Modified Option-4 algorithm (MO-4), Option-3 method (O-3) and Double Pass method (DP) from a common dataset and to determine the most efficient method in eliminating outliers.

MATERIAL AND METHODS

A single clinician recorded full mouth RAL with the Florida Disc Probe on four occasions over 6 months in 16 subjects (mean age 48.1 years) with untreated moderate Chronic Adult Periodontitis (mean Probeable Crevice Depth 2.9 mm).

RESULTS

2312 sites were available for analysis. Within-visit correlation coefficients for the two selected RAL measurements were 0.98 (P < 0.001) for O-4, MO-4 and O-3 and >or= 0.92 (P < 0.001) for DP. The maximum mean differences of within-visit RAL were - 0.05 mm for O-4, - 0.03 mm for MO-4, - 0.03 mm for O-3 and - 0.02 mm for DP. The standard deviations of these differences were <or= 0.44 mm for O-4, <or= 0.47 mm for MO-4, <or= 0.45 for O-3 and <or= 0.96 mm for DP. Repeated Measures Analysis of Variance (RMAV) showed a significant difference in RAL between visits for all methods (P < 0.003). RMAV, investigating predetermined between-method comparisons, showed a significant difference in RAL between visits (P = 0.0002) and a significant interaction between the order of the selected RAL and method (P = 0.0011). Within-visit RAL agreement to within 1.0 mm was achieved at >or= 99.9% sites for O-4, >or= 99.9% sites for MO-4, >or= 99.3% sites for O-3 and >or= 85.6% sites for DP. Remeasurement (in addition to two passes) was required over the study period at 16.6% sites for O-4, 13.2% sites for MO-4 and 13.0% sites for O-3: DP, by definition, required no additional measurements. The mean site-specific variances at all visits were <or= 0.1 mm(2) for O-4, MO-4 and O-3 and <or= 0.44 mm(2) for DP.

CONCLUSIONS

The Option-4 algorithm was found to be the most effective outlier reduction protocol currently available, producing the most reproducible data.

Site-specific attachment level change detected by physical probing in untreated chronic adult periodontitis: review of studies 1982-1997

BACKGROUND

Site-specific attachment level change, detected from sequential physical probing measurements, is currently the most common method of determining the progression/regression or stability of disease status in subjects with chronic adult periodontitis. The sensitivity and accuracy of detection is dependent on the type of probe used, the recording method, the measurement error, and the method of data analysis. In recent years, there has been world-wide interest in developing instruments and methods to minimize measurement error. Published data report disturbingly wide variation in the prevalences and rates of site-specific attachment level change which are difficult to reconcile with biological likelihood. The present paper aims to summarize the salient points from the key studies and to compare the results.

METHODS

The literature between 1982 and 1997 was reviewed for studies in which site-specific attachment level change was detected by physical probing methods in patients with chronic adult periodontitis.

RESULTS

The review documents 23 studies by probe generation, compares methods and results and summarizes the results according to the thresholds and probe type used. The 23 studies used an array of probe types from the 3 probe generations.

CONCLUSIONS

From this review, we conclude that: 1) There are surprisingly few papers which have addressed the question of site-specific attachment level change in untreated chronic adult periodontitis. 2) There are considerable differences in the probes used, in the thresholds achieved, in the number of measurements taken, in the number of subjects and sites studied, and in the duration of the studies. Valid comparisons between studies are, therefore, rarely possible. 3) Only 8 out of 23 papers from 1982 to 1997 have adequate data. Most papers report only losing sites and therefore ignore many of the measurements recorded. Only one paper describes losing sites, gaining sites, and sites showing exacerbation/remission patterns of change. 4) The range of changes described show such variation that it has to be concluded that we cannot reliably detect site-specific attachment level change by physical probing and thus, at the end of the 20th century, we have no clear idea of the natural history of this disease.