Exposure measurement in the association between periodontal disease and prematurity/low birth weight.

AIM To compare the use of different definitions for exposure measurement in cases of association between periodontal disease (PD) and prematurity and/or low birth weight (PLBW). MATERIAL AND METHODS A database from a previous case-control study was used to compare four different definitions for periodontitis: at least one site with probing depth > or =4 mm (1); at least one site with clinical attachment loss (CAL)> or =3 mm (2); at least four teeth with one or more sites presenting probing depth > or =4 mm, with CAL> or =3 mm at the same site (3); and at least four teeth with one or more sites with probing depth > or =4 mm, with CAL> or =3 mm at the same site and presence of bleeding on probing (4). The PD frequency, diagnostic values and adjusted association measurements were calculated. RESULTS PD frequency ranged from 33.1% to 94.7%. Odds ratio(adjusted) varied slightly according to the exposure measurement used. CONCLUSIONS The association between PD and PLBW weight was consistent, except for exposure measurement 1, i.e. using at least one site with CAL> or =3 mm for periodontitis diagnosis, while the magnitude of this varied according to the definition established.