Immunohistochemical findings of osteopontin expression in various odontogenic cyst and odontogenic tumour: A systematic review

Objective: This study aimed to assess osteopontin expression following immunohistochemical staining of odontogenic cysts and tumors. Methods: A systematic review was conducted based on PRISMA Statement. The literature search was carried out through PubMed, Scopus, and Science Direct databases, covering all the articles published up to October 2021, using a combination of the key terms ‘osteopontin’, ‘odontogenic tumor’, ‘odontogenic cyst’, and ‘expression’. The tool of the Joanna Briggs Institute Critical Appraisal Checklist for Cross Sectional Studies was applied to examine the quality of the selected articles. Results: The search strategy yielded in total 853 possibly relevant references. After removal of duplicates, 614 titles and abstracts were initially reviewed. From these, 22 were independently assessed in full text for eligibility, and seven studies were included to the review. The analysis revealed the frequency of osteopontin expression in odontogenic cysts as 35.3% for (-) score, 23.5% for (+) score, 21.6% for (++) score, 19.6% for (+++) score; and in odontogenic tumors as 11.3% for (-) score, 1.9% for (+) score, 3.8% for (++) score, and 83% for (+++) score. Conclusions: The present study showed different frequency of osteopontin expression between odontogenic cysts and tumors. The frequency of OPN expression with a (+++) score in odontogenic tumor was higher than that of in odontogenic cyst. The highest frequency of OPN expression with (-) score was shown in odontogenic cysts. Osteopontin has a different expression pattern related to the progressivity and recurrence of the lesion.