Thesis (Ph.D.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Oral and Maxillofacial Pathology

Background: Odontogenic cysts are distinctive disorders that affect oral and maxillofacial tissues. The majority of odontogenic cysts such as dentigerous cysts (DCs) and orthokeratinized odontogenic cyst (OOCs) show an indolent course, whilst others demonstrate an aggressive behavior and may have higher recurrence rate like odontogenic keratocysts (OKCs) and glandular odontogenic cysts (GOCs). Aim: This study aimed to compare FAK and PCNA expression in OKC, OOC, DC and GOC and to attempt to correlate the findings to their variable clinical behaviors. Moreover, this study aimed to clarify the role of EMT in invasion potential, proliferation and aggressiveness of these lesions, thus helping to predict their prognosis, reaching the best treatment modality for the patients and lowering the recurrence rates. Methodology: Double Immunostaining technique for FAK and PCNA was performed on the same tissue specimens using two types of chromogens (DAB and AEC). DAB chromogen was used for the assessment of nuclear expression of PCNA, while AEC chromogen was used for the assessment of cytoplasmic expression of FAK. Results: The greatest mean of the nuclear immunoexpression of PCNA was recorded in GOC group, followed by the OKC and OOC groups, whereas the lowest value was the DC group, while the greatest mean area percent of the cytoplasmic expression of FAK was recorded in OKC group, followed by the GOC and OOC groups, whereas the lowest value was recorded in DC group. Conclusions: OKC has the highest EMT ability followed by GOC, while GOC has the highest proliferation activity followed by OKC. On the other hand, OOC and DC have the lowest EMT ability and proliferation activity, which can explain the diverse behavior of those odontogenic cysts

Issued also as CD