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Objective: This study was conducted to correlate and compare the immunoexpression of sex‐determining region Y‐box 2 (SOX‐2) in oral leukoplakia (OL) lesions with that in normal buccal mucosa (control). Materials and Methods: In this observational study, OL with low‐risk (n = 34) and high‐risk (n = 33) dysplasia and control samples (n = 25) were subjected to immunohistochemical analysis for SOX‐2. In the epithelium, SOX‐2 positive and negative cells, as well as semiautomatic segmentation of the immunopositive nuclear area were counted. Statistical tests included chi‐square, one‐way analysis of variance, Tukey, and Games‐Howell. The level of significance was 5%. Results: Groups with OL lesions (low and high‐risk) showed higher mean numbers of SOX‐2 positive cells (63.47 ± 25.70 and 68.18 ± 21.17) compared to the control group (45.85 ± 27.38) (p = 0.00). Groups with OL lesions (low and high‐risk) exhibited higher mean positive nuclear area (0.24 ± 0.47 and 1.09 ± 2.06) compared to the control group (0.00 ± 0.01) (p = 0.01). Conclusion: Oral leukoplakia lesions showed a higher expression of SOX‐2, suggesting its contribution to the pathogenesis of OL. [ABSTRACT FROM AUTHOR]

The aim of this study is to compare the immunoexpression of metalloproteinases 1 and 8 in giant-cell fibroma, inflammatory fibrous hyperplasia and normal mucosa. Twenty-two cases of giant-cell fibroma, inflammatory fibrous hyperplasia and oral mucosa (control) each were subjected to immunohistochemistry using anti-metalloproteinase-1 and anti-metalloproteinase-8 antibodies. Eight images of each case were captured and analysed through the a) application of a count grid to count the number of positive neutrophils, macrophages, lymphocytes, plasma cells, fibroblasts and blood vessels to obtain the percentage of staining and b) semi-automated segmentation quantifying the stained area in square micrometres. Statistical tests included ANOVA Two-way, Kruskal Wallis and Games-Howell, with a significance level of 5%. An increased percentage of metalloproteinase-1-immunopositive blood vessels were observed in giant-cell fibroma (26.6 ± 22.4; p = 0.02) and inflammatory fibrous hyperplasia (34.3 ± 31.5; p = 0.01) compared with the control group (19.6 ± 9.2). No significant differences in inflammatory cells, fibroblasts and total area of metalloproteinase-1 and −8 were noted among the three groups. Metalloproteinase-1 apparently acts within the pathogenesis of giant-cell fibroma and inflammatory fibrous hyperplasia. [ABSTRACT FROM AUTHOR]

Objective The aim was to investigate collagen fibers in giant cell fibroma, inflammatory fibrous hyperplasia, and oral normal mucosa. Materials and methods Sixty-six cases were stained with picrosirius red. The slides were observed under polarization, followed by the measurement of the area and the percentage of the type I and type III collagens. The age and gender were obtained from the clinical records. Results No differences could be observed in both the area and percentage of the type I and type III collagens within the categories of lesions and normal mucosa. In the giant cells fibroma, a greater area and percentage of type I collagen could be identified in individuals of less than 41.5 years (p < 0.05). Conclusion The distribution of type I and type III collagen fibers in the studied lesions followed a similar pattern to that observed in the normal mucosa, indicating a normal collagen maturation process of type III to I. The study supports that multinucleated and stellate cells of the giant cell fibroma appear to be functional within collagen types III and I turnover. The greater amount of type I collagen identified in giant cell fibroma in individuals of less than 41.5 years reinforce the neoplastic nature of lesion. [ABSTRACT FROM AUTHOR]