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.