Ultrastructural Changes of Collagen in Different Histopathological Grades of Oral Submucous Fibrosis

Oral submucous fibrosis (OSMF) is a potentially malignant disorder and a crippling condition of oral mucosa. It is usually seen in adults with areca nut chewing habit, which is characterized by changes in the connective tissue fibers leading to stiffness of the mucosa and restricted mouth opening. Patients with severe cases have distinct difficulties in chewing, swallowing, and speaking. It predominantly occurs in Indians and other population of the Indian subcontinent with a prevalence of 0.2%-0.5%. The potentiality of malignant transformation associated with OSMF is much higher with a range of 4.5%-7.6%. This article is about the ultrastructural changes pertaining to collagen and with respect to the histopathological grades of OSMF.

A total of 20 biopsy samples from clinically diagnosed OSMF subjects and 5 healthy controls were collected. After obtaining the biopsy, the specimens were divided into two halves, of which one was studied under light microscope and the other half was observed under transmission electron microscope.

Of the 20 subjects in the study group, most of the subjects were in the 20-29 years age group with an overall male predilection (19 subjects). Four subjects were in grade 1, nine were in grade 2, and seven were in grade 3. Collagen showed sparse to dense fibrosis and normal to thick collagen bundles, and some subjects showed encroachment of collagen into the blood vessels.

This study showed definitive changes with respect to collagen in the OSMF samples compared to the controls. The changes were found to be increasing with the progression of the disease to the higher grades. The changes were pertaining to the collagen and were drawing toward an increased fibrosis of the connective tissue, which compresses the blood vessels. Hence, the state of hypoperfusion and subsequent epithelial atrophy can be considered in the progression of disease to the higher grades.