ABSTRACT
OBJECTIVE: To describe the ultrastructural features of hereditary gingival fibromatosis (HGF) in affected family members and compare microscopic findings with normal gingival (NG) tissue. STUDY DESIGN: Gingival tissue samples from nine patients with HGF from five unrelated families were evaluated by transmission electron microscopy. Nine NG tissue samples were used for comparison. RESULTS: Areas containing collagen fibrils forming loops and folds were observed in both groups, whereas oxytalan fibers were frequently identified in the HGF group. The diameter of collagen fibrils and the interfibrillar space among them were more uniform in the NG group than in the HGF group. Fibroblasts were the most common cells found in both the HGF and NG groups and exhibited enlarged, rough endoplasmic reticulum, mitochondria with well-preserved crests, conspicuous nucleoli, and euchromatic chromatin. Other cells, such as mast cells, plasma cells, and macrophages, were also observed. CONCLUSIONS: HGF tissues had ultrastructural characteristics that were very similar to those of NG tissues. Oxytalan fibers were observed more frequently in the HGF samples than in the NG samples. Other studies of HGF in patients from different families should be performed to better understand the pathogenesis of this hereditary condition.
