EXTENT AND SEVERITY OF PERIODONTAL DESTRUCTION BASED ON PARTIAL CLINICAL ASSESSMENTS

The aim of the present study was (i) to identify the 10 approximal tooth sites that provide Extent and Severity estimates of clinical attachment loss which are maximally coherent to the full mouth scores, and (ii) to evaluate the applicability of such a partial recording system. Data from two subject samples, comprising 192 subjects aged 30-64 yr (sample A) and 175 subjects aged 35-80 yr (sample B), were involved in the development and the evaluation of the system, respectively. Approximal probing attachment loss (PAL) measurements were available from all subjects. A PAL value of > 1 mm was required for a tooth site in order to qualify for the Extent and Severity computations. A full mouth bivariate Extent and Severity Index (FESI) was firstly calculated for every subject in sample A. Multiple regression models applied on data derived from the same sample identified the 10 approximal tooth sites which provided the best correlation to the full-mouth scores (correlation coefficients between partial and full mouth scorings of Extent and Severity 0.85 and 0.88, respectively). All tooth types were found to be represented in this set of sites and the ratio of mesial/distal sites was 6/4. The applicability of a partial recording system (PESI) based on these sites was evaluated in sample B. Fully comparable estimates between PESI and FESI values were obtained, but the degree of correlation varied at different ages. Further adjustments by means of regression models failed to increase the validity and reliability of the PESI. It was concluded that the proposed partial recording system is robust and warrants further evaluation in epidemiologic studies of destructive periodontal disease.