In vitro determination of the forceps level for extraction of teeth for periodontal reasons.

The aim of the present study was to validate dentists' periodontal reasons for extraction by comparison with the in vitro periodontal status of extracted teeth. A national systematic random sample of Norwegian dentists (n = 500) was requested to record primary, secondary and tertiary reasons for tooth extraction for a period of 2 weeks in 1988. The response rate was 70%. The extracted permanent teeth from the first 2 patients of each dentist were collected. Of the 365 teeth, 329 satisfied the criteria for assessment of periodontal attachment after staining. Using a dissecting microscope (10x), 4 to 8 linear measurements were recorded per tooth. 159 of the 329 teeth had loss of periodontal support. Of the 93 teeth for which the dentists' reason for extraction included periodontal considerations, 1% had 1-10% loss of attachment, 59% had 11-50% loss and 40% had 51-76% loss of periodontal support. There was a significant correlation between in vitro measurements of attachment loss and a ranking of teeth on a scale from 1 to 3 based on the dentists' emphasis on periodontal reasons for extraction (The Spearman Rs = 0.29, p < 0.01). The results suggest that the forceps level for removal of teeth for periodontal reasons was set at a relatively early stage of the disease process by Norwegian dentists, and that there was a weak association between attachment loss and the dentists' emphasis on periodontal reasons for extraction.