COMPARATIVE ESTIMATION OF PERIODONTAL CONDITIONS BY MEANS OF DIFFERENT INDEX SYSTEMS

The aim of the present study was to compare epidemiological data of periodontal disease obtained from a sample of adults by means of different, commonly employed, partial and full-mouth index systems, in order to explore the amount of discrepancy attributed to the methodology per se. 169 dentate subjects, aged 25-64 years, were subjected to a clinical examination, including circumferential probing assessments of pocket depth (PPD) and attachment level (PAL) at all teeth present. The individual mean % of tooth sites with PPD of greater-than-or-equal-to 6 mm and the % of subjects exhibiting at least one such deep pocket were calculated based on (i) full-mouth data, (ii) data derived from the buccal and mesial surfaces from 1 randomly selected upper and 1 lower quadrant, (iii) probing assessments at the 6 ''Ramfjord teeth'', (iv) the full-mouth community periodontal index for treatment needs (CPITN), and (v) the partial CPITN based on 10 index teeth. The PAL data were analyzed by means of 3 versions of the extent and severity index, 1 generated by full-mouth assessments and 2 by partial assessments based on 28 and 10 tooth sites, respectively. In the entire sample, the individual mean % of sites with PPD of greater-than-or-equal-to 6 mm generated by the different systems ranged between 5.0 and 4.2 sites/subject. By full-mouth CPITN scorings, an average of 1.0 score-4 sextants/subject was recorded, while the partial CPITN generated a corresponding value of 0.8 score-4 sextants/subject. The prevalence of subjects with at least one deep pocket was found to be (i) 47% by the full-mouth examination, (ii) 24% by the half-mouth examination, (iii) 26% by the use of the ''Ramfjord teeth'', and (iv) 44% by the partial CPITN. Variations in the accuracy of the partial recordings were observed in different age groups. Analysis of the PAL data generated extent values ranging between 93 and 96% and severity values between 3.6 and 3.9 mm. It was concluded that partial recording systems (i) provide reasonably valid estimates of the individual mean number of ''affected'' tooth sites; however, (ii) they grossly underestimate the prevalence of subjects exhibiting deep periodontal pockets.