Dental nomograms for benchmarking based on the study of health in Pomerania data set

Benchmarking is a means of setting goals or targets. On an oral health level, it denotes retaining more teeth and/or improving the quality of life. The goal of this pilot investigation was to assess whether the data generated by a population-based study (SHIP 0) can be used as a benchmark data set to characterize different practice profiles.

The data collected in the population-based study SHIP (n=4310) in eastern Germany were used to generate nomograms of tooth loss, attachment loss, and probing depth. The nomograms included twelve 5-year age strata (20-79 years) presented as quartiles, and additional percentiles of the dental parameters for each age group. Cross-sectional data from a conventional dental office (n=186) and from a periodontology unit (n=130, Greifswald) in the study region as well as longitudinal data set of a another periodontology unit (n=135, Kiel) were utilized in order to verify whether the given practice profile was accurately reflected by the nomogram.

In terms of tooth loss, the data from the conventional dental office agree with the median from the nomogram. For attachment loss and probing depth, some age groups yielded slight but not uniform deviations from the median. Cross-sectional data from the periodontology unit Greifswald showed attachment loss higher than the median in younger but not in older age groups. The probing depth was uniformly less than the median and tended toward the 25th percentile with increasing age. The longitudinal data of the Unit of Periodontology in Kiel showed a pronounced trend towards higher percentiles of residual teeth, meaning that the patients retained more teeth.

The profile of the Pomeranian dental office does not deviate noticeably from the population-based nomograms. The higher attachment loss of the Unit of Periodontology in Greifswald in younger age strata clearly reflects their selection because of periodontal disease; the combination of higher attachment loss and decreased probing depth may reflect the success of the treatment. The tendency of attachment loss towards the median with increasing age may indicate that the Unit of Periodontology in Greifswald does not fulfill its function as a special care unit in the older subjects. The longitudinal data set of the Unit of Periodontology in Kiel impressively reflects the potential of population-based data sets as a means for benchmarking. Thus, nomograms can help to determine the practice profile, potentially yielding benefits for the dentist, health insurance company, or--as in the case of the special care unit--public health research.