Matrix Metalloproteinase-9 (MMP-9) Expression in Different Subtypes of Ameloblastoma

Background: Ameloblastoma is a common benign odontogenic tumor of the jaw with a local invasive and highly destructive behavior and can develop in any age, with peak prevalence in 3rd–4th decade. Ameloblastoma can be divided into six histological types: follicular, plexiform, acanthomatous, desmoplastic, granular, and basal cell. Matrix metalloproteinase-9 (MMP-9) (92-kD gelatinase/type IV collagenases = gelatinase B) is involved in bone resorption by degradation of extracellular matrix and osteoclasts recruitment. Recent studies have found that MMP-9 is expressed by ameloblastoma and has a role in ameloblastoma local invasiveness. Objective: To analyze MMP-9 expression between different histological types of ameloblastoma. Material and Method: Forty samples of ameloblastoma were collected through consecutive sampling and the MMP-9 expression was detected using immunohistochemistry. Result: All samples showed positive MMP-9 expression with moderate to strong intensity. 82.4 % plexiform type and 83.3 % mixed type have strong immunoexpression, significantly different with follicular type with only 36.4 % (P < 0.05). Conclusion: Ameloblastoma plexiform and mixed type have higher MMP-9 expression than ameloblastoma follicular type. Different MMP-9 expression may contribute in different ameloblastoma biological behavior.