Visible third molars as risk indicator for increased periodontal probing depth

Abstract

Purpose: To assess the relationship between visible third molars and the periodontal status of teeth more anterior in the mouth from reports that included periodontal probing data for all teeth.

Materials and methods: Each of 4 reports that included periodontal probing data, 6 probing sites for all teeth, including third molars collected by trained, clinician examiners, were briefly summarized. The design, strengths, and weaknesses of each of the 4 studies were compared and summarized. A Forest plot was used to combine the findings from the 4 studies comparing the mean second molar probing depth differences in mm by the presence of at least 1 visible third molar or no visible third molar.

Results: A review of the data from 4 reports, 1 from middle-age adults and 3 from young adults, suggested an association between the visible presence of a third molar and increased periodontal probing depths on teeth more anterior in the mouth, predominately the first and second molars. Coupled with the probing depth around the third molars, the result was an expanded surface area at the biofilm-gingival interface.

Conclusions: Although all those with retained third molars are not at increased risk, the summary data we have reported suggest that those with a visible third molar are more likely to have greater periodontal probing depths overall, particularly on second molars, and a greater surface area of the biofilm-gingival interface compared with those with no visible third molar.