Résumé
Statement of the Problem: Odontogenic keratocyst [OKC] is a developmental odontogenic cyst with specific histopathological features, high recurrence rate, and aggressive clinical behavior. Angiogenesis might be considered as an important factor for the growth, expansion, and distribution of this lesion
Purpose: The aim of the present study was to determine the mean vascular densities [MVD] of OKCs and dentigerous cysts to evaluate their relationship with the biolog-ic behavior of these lesions
Materials and Method: In this cross-sectional analytical study, angiogenesis was assessed in OKC and dentigerous cyst by measuring the MVD. Immunohistochemis-try was carried out using CD34 and CD105. The results were analyzed with inde-pendent samples t-test. The data were analyzed, setting p value at 0.05
Results: The MVDs with the use of CD34 and CD105 markers were significantly higher in OKC compared to dentigerous cyst [p< 0.05]. In addition, MVDs obtained by CD105 in dentigerous cysts and OKC were significantly less than those based on CD34 [p< 0.05]
Conclusion: Based on the results of the present study, it can be suggested that angi-ogenesis might be one of the possible mechanisms involved in higher aggressive biologic behavior and greater recurrence rate of OKC compared to dentigerous cysts
Résumé
Statement of the Problem: Peripheral and central giant cell granuloma are two common benign lesions of the oral cavity. In spite of histopathological similarities, they have different clinical behaviors. Cathepsin D is a lysosomal enzyme which has different functions on the basis of protein and applied peptide cleavage
Purpose: This research aimed to evaluate and compare the expression level of Cathepsin D in these two lesions to find the reasons for the differences in clinical and biologic characteristics
Materials and Method: The expression of Cathepsin D was investigated by using the immunohistochemistry method in 20 samples of peripheral giant cell granuloma and 20 samples of central giant cell granuloma. The percentage of stained giant cells [labeling index], the intensity of staining of giant cells, and staining-intensity-distribution in both groups were calculated and compared
Results: The labeling indices of Cathepsin D in peripheral giant cell granuloma and central giant cell granuloma were 95.9 +/- 4.03 and 95.6 +/- 2.34, respectively. There was no significant difference in the percentages of stained giant cells between the two groups [p= 0.586]. The intensity of staining of giant cells in central giant cell granuloma was stronger than that of peripheral giant cell granuloma [p> 0.001]. Staining- intensity- distribution of giant cells in central giant cell granuloma was significantly greater than that of the peripheral type of lesion [p= 0.001]
Conclusion: The higher expression level of Cathepsin D in central giant cell granuloma compared to peripheral type of lesion can explain more aggressive behavior of central giant cell granuloma
Résumé
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
Résumé
Keratoacanthoma [KA] is a comparatively common low-grade tumor that initiates in the pilo-sebaceous glands and pathologically mimics squamous cell carcinoma [SCC]. Essentially, strong debates confirm classifying keratoacanthoma as a variant of invasive SCC. The clinical behavior of KA is hardly predictable and the differential diagnosis of keratoacanthoma and other conditions with keratoacanthoma-like pseudocarcinomatous epithelial hyperplasia is challenging, both clinically and histopathologically. This article aims to illustrate and explicate some of these complicated issues by presenting two cases of KA and a relevant review of literature. It also targets the clinical, histopathologic, and immuno-histochemical features of these two cases. Both presented lesions of this study had appeared on the vermilion border of the lower lip and no vascular or perineural invasion was observed. The results of the immuno-histochemical survey, particularly in staining with marker CD30, confirmed the differential diagnosis of keratoacanthoma from keratoacanthoma-like pseudocarcinomatous proliferations which was consequent to the CD30[+] lymphoid infiltration. Histopathological and immunohistochemical investigation is necessary to disprove the invasive biologic behavior of keratoacanthoma and also to refute all conditions with keratoacanthoma-like pseudocarcinomatous epithelial hyperplasia
Résumé
Statement of the Problem: Odontogenic cysts and tumors are the most frequent osseous destructive lesions of the jaws; however, there is little information regarding the relative frequency of these lesions among the Iranian population
Purpose: The purpose of this study was to determine the distribution of clinically and histologically- diagnosed odontogenic cysts and tumors during a period of 13 years in Hamadan, and also its correlation with age, gender, and the site of the lesion
Materials and Method: A descriptive cross-sectional study was performed on 413 oral and maxillofacial specimens during 1996 to 2008.The age and the gender of patients, as well as the site of lesion were recorded. The data were analyzed using SPSS software
Results: Totally, 70 specimens were recorded as odontogenic cysts and 11 specimens were diagnosed as odontogenic tumors. The most frequent odontogenic cysts were dentigerous cysts [27.2%], followed by radicular cysts [18.6%] and odontogenic keratocysts [18.6%]. In addition, cysts were more frequent in male than female individuals. Ameloblastoma was the most frequent odontogenic tumor [64%]
Conclusion: Odontogenic cysts were in correlation with age, gender and location. These results showed that dentigerous cyst and odontogenic keratocyst were more frequent than other studies. More investigations should be performed to determine the frequency of odontogenic tumors in Iran
Résumé
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
Résumé
Oral squamous cell carcinoma [OSCC] is the most common type of oral cancer and dentists have a vital role in its prevention and early detection. The purpose of the present study was a comparative evaluation of knowledge between fifth and sixth year dental students and general dentists in Hamadan about to OSCC. This descriptive cross-sectional study was carried out in Hamadan in 2009. Eighty general dentists and 70 dental students participated in the study and filled out our questionnaire. Data were analyzed via SPSS software, version 16, by t-test and Pierson co-efficient correlation. The mean knowledge score was 8.55 +/- 2.21 and 6.48 +/- 2.34 of 13 in students and dentists respectively which was significantly different [P< 0.001]. There was not a significant correlation between either age, gender, interval of last study about OSCC, the interest in participation in related seminars and self evaluation of students about OSCC, with their knowledge score but dentists' knowledge were declined by increase in age, time passed from graduation and the last time of their study about OSCC statistically. This study indicated that knowledge of dental students and general dentists about OSCC is not enough in Hamadan; also, there was a significant difference between them and it seems there needs to be a greater emphasis on various educational programs about this subject both before and after graduation