ABSTRACT
Statement of the Problem: Lichen planus is a mucocutaneous disease that is relatively common in middle aged individuals. Some studies have shown that oral lichen planus has a potential to progress to squamous cell carcinoma.p21 is a cyclin-dependent kinase inhibitor that regulates the cell cycle, thus it acts as an inhibitor in cell proliferation
Purpose: This study was aimed to evaluate and compare the immunostaining of p21 [as a proliferation inhibitory factor] in oral lichen planus [OLP] and oral squamous cell carcinoma [OSCC]
Materials and Method: In this descriptive cross-sectional study, p21expression was investigated in 24 samples of oral lichen planus [OLP], 24 samples of oral squamous cell carcinoma [OSCC] and 24 samples of oral epithelial hyperplasia [OEH] by employing immunohistochemical staining
Results: The mean percentage of p21-positive cells in OSCC [54.5 +/- 6.6] was significantly higher than that in OLP [32.8 +/- 6.08] and OEH [9.4 +/- 3.8]. Moreover, OLP samples expressed p21 significantly higher than the OEH. Kruskal Wallis test revealed a statistically significant difference between the groups regarding the intensity of staining [p< 0.001]
Conclusion: According to the findings of this study, the expression of p21 might be related to the potential carcinogenic transformation of lichen planus to SCC. Therefore, continuous follow-up periods for OLP are recommended for diagnosis of the malignant transformations in early stages
ABSTRACT
Statement of the Problem: Soft tissue reactive lesions are the most common lesions of the oral cavity. Although many studies have shown the interaction of mast cells with fibroblasts and their participation in fibrosis, the role of mast cells in these lesions is not well understood
Purpose: The aim of this study was to evaluate the mast cells [MCs] count in oral soft-tissue reactive lesions including peripheral giant cell granuloma [PGCG], peripheral ossifying fibroma [POF], irritation fibroma [IF] and normal oral mucosa
Materials and Method: In this cross-sectional study, 50 samples including IF, PGCG, POF [14 cases for each group] and 8 cases of normal oral mucosa were stained with tryptase antibody through immunohistochemistry. The number of mast cells was counted in 5HPF containing maximum counts for each section stained with tryptase. Statistical analysis including Chi-square test and Tukey test with a significance level of 0.05 were considered
Results: The number of MCs was found to have increased in reactive lesions compared with normal oral mucosa. MCs count in the POF group was higher than the others
Conclusion: These findings suggest a possible role of mast cells in the pathogenesis of reactive oral lesions and induction of fibrous tissues. Chemical mediators released from mast cells might influence other cells, especially fibroblasts, to induce fibrosis
ABSTRACT
Statement of the Problem: Ameloblastoma is the most common odontogenic tumor which is slow-growing, locally invasive and exhibit specific biologic behavior and high recurrence rate. Likewise, odontogenic keratocyst is a developmental odontogenic cyst that has a high recurrence rate and aggressive behavior. There are limited studies considering the relationship between the angiogenesis factors and the biologic behavior of these lesions
Purpose: the aim of this study was to evaluate the mean density of vessels in odontogenic keratocysts and ameloblastoma and investigate its possible relationship with biological behavior of these lesions
Materials and Method: In this descriptive-analytic cross-sectional study, 40 cases, comprising 10 odontogenic keratocysts and 30 ameloblastomas [10 plexiform, 10 follicular, and 10 unicystic type] were selected and were stained immuno-histochemically with CD34 and CD105. The micro vessel density was assessed and compared in all groups. T- test for the independent samples' One- way Anova, Wilcoxon test and Tukey tests were adopted for statistical analysis
Results: A statistically significant difference was observed in mean vascular density [MVD] between the odontogenic keratocyst and ameloblastoma groups concerning the CD105 and CD34 markers [p= 0.005, p= 0.000, respectively]. The MVD was significantly higher in ameloblastomas than odontogenic keratocyst. MVD with CD34 was significantly higher than MVD with CD105 in ameloblastomas [p= 0.00]
Conclusion: It can be suggested that angiogenesis might be one of the mechanisms that is more possible to contribute the aggressive biological behaviors in ameloblastoma rather than odontogenic keratocyst