An unusual form of chronic gingivitis: an ultrastructural, histochemical, and immunologic investigation.

Gingival tissue from a patient suffering from an unusual form of gingivitis, previously described as plasma cell gingivitis, has been subjected to ultrastructural, histochemical, and immunologic investigation. Macrophages and T-lymphocytes infiltrated the oral epithelium where a dissecting type of injury was produced, predominantly in the lower spinous layer. Interkeratinocyte junctions were disrupted and collections of isolated desmosomes were observed in the intercellular spaces. It is postulated that the primary lesion in this atypical gingivitis lies in the epithelium and that the plasma cell infiltrate in the connective tissue is secondary to this. No allergen could be identified, and over a period of 7 years the condition has shown a tendency to resolve spontaneously.