Ultrastructural evaluation of gingival connective tissue in hereditary gingival fibromatosis.
OBJECTIVE
To describe the ultrastructural features of hereditary gingival fibromatosis (HGF) in affected family members and compare microscopic findings with normal gingival (NG) tissue.


METHODS
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.
Full Professor, Dental School, State University of Montes Claros, Av Rui Braga - Vila Mauriceia - Campus Darcy Ribeiro - CEP 39401-089, Montes Claros, Minas Gerais, Brazil. Electronic address: Sabinapego@yahoo.com.br.
Sabina Pena B
SP
Pêgo
Adjunct Professor, Institute of Biomedical Science, Department of Morphology, Federal University of Uberlandia, Uberlandia, Minas Gerais, Brazil.
Paulo Rogério
PR
de Faria
Full Professor, Dental School, State University of Montes Claros, Av Rui Braga - Vila Mauriceia - Campus Darcy Ribeiro - CEP 39401-089, Montes Claros, Minas Gerais, Brazil.
Luis Antônio N
LA
Santos
Associate Professor, Department of Oral Diagnosis, School of Dentistry, State University of Campinas, São Paulo, Brazil.
Ricardo D
RD
Coletta
Professor, Department of Oral Dentistry, Federal University of Juiz de Fora, Governador Valadares, Minas Gerais, Brazil.
Sibele Nascimento
SN
de Aquino
Full Professor, Dental School, State University of Montes Claros, Av Rui Braga - Vila Mauriceia - Campus Darcy Ribeiro - CEP 39401-089, Montes Claros, Minas Gerais, Brazil.
Hercílio
H
Martelli-Júnior
D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000648:ultrastructure; D003238:Connective Tissue / Q000648:ultrastructure*; D003240:Connective Tissue Diseases / Q000235:genetics* / Q000473:pathology; D004547:Elastic Tissue / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D005260:Female; D005351:Fibromatosis, Gingival / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged
D003094:Collagen