Stromal characterization and comparison of odontogenic cysts and odontogenic tumors using picrosirius red stain and polarizing microscopy: A retrospective and histochemical study.

INTRODUCTION: Odontogenic lesions represent a range of conditions, the features of which probably depend on the stage of induction towards tooth formation reached prior to neoplastic or hamartomatous proliferation. It has been also suggested that inductive changes may allow progression from one type of odontogenic tumor to another. The epithelium also plays an important role in the pathogenesis of these lesions; even stroma is likely to play an equally important role in the pathogenesis and biological behavior. So, this study was performed to investigate, compare, and correlate different types of collagen fibers in odontogenic cysts and odontogenic tumors. MATERIALS AND METHODS: Thirty each pre‑diagnosed odontogenic cysts and tumors were histochemically analyzed using a special stain (Picrosirius red stain) and polarizing microscopy. RESULTS: Seven cases (99%) of inflammatory cysts exhibited predominantly greenish‑yellow birefringence indicating procollagen, intermediate, or pathologic collagen fibers suggestive of loosely packed collagen fibers. Predominant yellowish‑orange birefringence exhibited by 21 cases (99%) of developmental cysts was comparable to the yellowish‑orange and orangish‑red to red birefringence exhibited by odontogenic tumors suggesting tightly packed fibers. CONCLUSIONS: The Picrosirius red stain in conjunction with polarizing microscopy serves as a specific and sensitive tool in characterizing collagen fibers in odontogenic cysts and odontogenic tumor.

Comparative study of clinicofunctional staging of oral submucous fibrosis with qualitative analysis of collagen fibers under polarizing microscopy.

Objective : The aim of the study was to assess the severity of the disease in oral submucous fibrosis (OSF), correlate the clinical, functional staging with histopathological staging, and analyze collagen distribution in different stages of OSF using the picrosirius red stain under polarizing microscopy. Materials and Methods : The study included randomly incorporated 50 subjects, of whom 40 were patients with OSF, and 10 were in the control group. Clinical, functional staging in OSF cases was done depending upon definite criteria. A histopathological study was conducted using the hematoxylin and eosin stain and picrosirius red stain. Collagen fibers were analyzed for thickness and polarizing colors. Furthermore, clinical, functional, and histopathological stages were compared. Statistical Analysis : Descriptive data which included mean, SD, and percentages were calculated for each group. Categorical data were analyzed by the chi-square test. Multiple group comparisons were made by one-way ANOVA followed by Student's t-test for pairwise comparisons. For all tests, a P-value of 0.05 or less was considered for statistical significance. Results : As the severity of the disease increased, clinically, there was definite progression in subjective and objective symptoms. Polarized microscopic, examination revealed, there was a gradual decrease in the green-greenish yellow color of the fibers and a shift to orange red-red color with increase in severity of the disease. Thereby, it appeared that the tight packing of collagen fibers in OSF progressively increased as the disease progressed from early to advanced stages. We observed that the comparison of functional staging with histopathological staging was a more reliable indicator of the severity of the disease. Conclusion : In the present study, we observed that mouth opening was restricted with advancing stages of OSF. The investigation also points to the importance of assessing the cases of OSF, especially with regard to functional and histological staging in planning the treatment.