Histologic changes associated with the use of loose and portion-bag packed Swedish moist snuff: a comparative study.

This study was to identify histologic tissue changes in the oral mucosa and to compare them in specimens from users of loose can-packed and portion-bag-packed moist snuff. The material consisted of biopsies from 252 regular snuff users. 184 using exclusively loose and 68 portion-bag snuff. An array of structural changes appearing in different combinations were identified among the 252 specimens. Two major patterns were recognized based on changes in the surface layer. Type 1 was characterized by an increased epithelial thickness with vacuolated cells and frequent chevron type changes. Type 2 showed a variably thickened surface layer with evidence of keratinization. Based on these findings, 14 carefully matched pairs of loose and portion-bag users were analyzed and compared. Loose snuff users showed predominantly histologic Type 1 changes while portion-bag users showed more histologic Type 2 or only very discrete changes.