This study was designed to evaluate the relationship of certain clinical and biochemical measures of periodontal pathology at anatomically related gingival sites. The maxillary first molar--second bicuspid region was studied in patients with gingivitis and periodontitis. The mesiobuccal site on the first molar was compared to the mesiopalatal and direct buccal sites on the molar and the distobuccal site on the second bicuspid. Probing depth, attachment level, gingival index, gingival crevicular fluid (GCF) volume, and GCF levels of the lysosomal enzyme B-glucuronidase (BG), the cytoplasmic enzyme lactate dehydrogenase, IgG and the protease-inhibitor alpha-2-macroglobulin were studied. For the 3 anatomical pairs that were analyzed, the correlation coefficients for the GCF constituents were generally higher than the correlations for the clinical parameters. The mean correlations for the GCF constituents were higher for the periodontitis patients as compared to the gingivitis patients. For the periodontitis patients, BG activity was correlated at adjacent proximal sites, approached significance at adjacent papillary sites, but was not significantly correlated at adjacent facial-proximal sites. This data suggests that sampling of BG activity from a mesiobuccal site provides information about the anterior papillary unit. In contrast, IgG in GCF collected from the mesiobuccal site on the first molar was significantly correlated with the total IgG in the 3 other sites.(ABSTRACT TRUNCATED AT 250 WORDS)