Histologic evaluation of periodontal tissues generally has included only areas adjacent to the gingival crevice, without knowledge or quantitation of alveolar crest osteoclastic (periodontitis) activity and infiltrate. The purpose of this study was to use human autopsy material to quantitate collagen and cell types adjacent to presumed periodontitis activity and quiescence, each in the same individual. Thirteen subjects contributed 4 sites each, 2 exhibiting alveolar crest periosteal osteoclasts in resorption lacunae/periodontitis activity (OC/PA) and 2 with no osteoclasts or resorption lacunae/ periodontal quiescence (NOC/PQ). Tissue and cell morphotypes were quantitated by 2 evaluators at 100 intersects in 0.06 mm2 fields progressing from the alveolar crest toward the gingival crevice. Cell morphotypes/tissue components were compared between groups and fields using a general linear model with repeated measures. OC/PA fields adjacent to the alveolar crest contained significantly more intersects with macrophage-like cells (10.7+/-1.1 versus 5.3+/-0.6%, P=0.0003), lymphocytes (4.6+/-1.1 versus 0.7+/-0.2%, P=0.0013), plasma cells (13.3+/-2.7 versus 2.1+/-0.6%, P=0.0004), and less with collagen (48.9+/-3.5 versus 75.0+/-2.0%, P=0.0001) than NOC/PQ fields. Numbers of lymphocytes and plasma cells increased (P=0.0006 and P=0.0002, respectively), and fibroblasts and collagen decreased (P=0.0024 and P=0.0001, respectively) in fields up to 1 mm closer to the gingival crevice. However, apparent osteoclastic activity in periodontitis subjects is associated with a significant inflammatory cell infiltrate, especially macrophages and plasma cells.