Early soft tissue pathosis associated with impacted third molars without pericoronal radiolucency

Objectives. This study was performed to histologically evaluate soft tissue pathosis in pericoronal tissues of impacted third molars that did not exhi bit pathologic pericoronal radiolucency. Study design. One hundred impacted third molars without evidence of abnorma l pericoronal radiolucency (follicular space <2.0 mm) were removed for reas ons other than participation in this study, and the pericoronal tissues wer e submitted for histopathologic examination. Specimens were fixed and proce ssed routinely and were stained with hematoxylin and eosin before independe nt evaluation by each of 2 oral pathologists. A subset of both diseased and healthy tissues underwent additional evaluation for the presence of prolif erating cell nuclear antigen (PCNA) for assessment of cellular activity. Results. Of the specimens submitted, 34% showed squamous metaplasia suggest ive of cystic change equivalent to that found in dentigerous cysts. Soft ti ssue pathosis was significantly higher in patients over 21 years of age (P = .001). Five of 8 diseased specimens demonstrated PCNA uptake, whereas non e of 10 healthy specimens were PCNA positive. Conclusions. These findings suggest that radiographic appearance may not be a reliable indicator of the absence of disease within a dental follicle. W e conclude that the incidence of soft tissue pathologic conditions is highe r than generally assumed from radiographic examination alone.