ABSTRACT
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
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
ABSTRACT
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