Hend Mohammed Wagieh, Safa Fathy Abd El-Ghani And Asmaa Emad El-Din Mohammed,

ABSTRACT
Odontogenic Cysts And Tumors Have A Wide Spectrum Of Histopathologic And Clinical Characteristics, Ranging From Benign Non-invasive To Locally Invasive Or Malignant Lesions. However, Little Is Elucidated About Their Pathogenesis. The Aim Of Study Was To Evaluate The Immunohistochemical Expression Of Claudin-1 And Claudin-3 In The Most Common Odontogenic Lesions. Comparing The Expression Levels Of These Two Markers Among Those Lesions And Finally, Correlation Of The Obtained Results With Their Biological Behaviors Were Also Performed. Forty Archival Cases Of Radicular Cyst, Odontogenic Keratocyst, Unicystic Ameloblastoma And Ameloblastoma (10 Cases Each) Were Stained With Hematoxylin And Eosin For Histological Examination. Streptavidin-biotin Method Was Used For Immunohistochemical Staining By Anti Claudin-1 And Anti Claudin-3 Antibodies. Our Results Revealed That The Expression Level Of Both Markers Was Gradually Decreased Starting From Radicular Cyst To Odontogenic Keratocyst, Unicystic Ameloblastoma Until Reaching Its Lowest Value In Ameloblastoma. The Statistical Analysis Of The Current Work Revealed A Highly Significant Difference In Area Percentage Of Both Markers Among The Examined Groups. In Addition, The Area Percentage Of Claudin-1immunoexpression Was Much Higher Than That Of Claudin-3, And The Correlation Between Both Markers Was Positive. In Conclusion, Claudins-1 And -3 Could Be Useful Prognostic Biomarkers In Odontogenic Lesions. However, Claudin-1 Is More Specific For Odontogenic Lesions Than Claudin-3. Besides, They Could Aid In Differentiation Of The Neoplastic From Non-neoplastic Odontogenic Lesions And Could Be Auxiliary Indicators Of Aggressiveness And Invasion Potentials.