Expression of BMP-4 in dentigerous cyst and ameloblastoma: Is it a differentiation measure?

Purpose: This study aimed to determine the expression of Bone Morphogenic Protein-4 (BMP-4) in dentigerous cyst (DC), unicystic-ameloblastoma (UA), and Multicysticameloblastoma (MA), and assess whether this marker can be a differentiation measure. Materials and methods: This study included 30 DC, 30 UA, and 30 MA blocks if the histopathologic diagnosis of the lesion was definitive, the clinical information and medical records were complete, and the microscopic slides and the paraffin block were available. Age, gender, and location of the lesion were recorded. The samples were analyzed after the immunohistochemical staining (Envision technique). BMP-4 marker was evaluated and reported using Intensity Score (IS), Proportional Score (PS), and Total score (TS). The data were analyzed using SPSS version 21.0. Kruskal-Wallis and Mann-Whitney U tests were applied at the significance level of 0.05. Results: In this study, DCs, UA, and MA had a significant tendency to occur in males compared to females (p<0.001, p<0.001, and p<0.001 respectively), and in the mandible compared to the maxilla (p=0.02, p=0.024, and p=0.02 respectively). The epithelial IS was significantly different among three lesions (p<0.001). IS was higher in MA than UA and DC (p<0.001 and p=0.006, respectively). The IS was not significantly different among the three lesions in connective tissue and around micro-vessels (p=0.3 and p=0.26 respectively). The PS in the epithelium and connective tissue of DC, UA, and MA had no statistical difference (p=0.549 and p=0.540 respectively). The epithelial TS was statistically different among DC, UA, and MA (p<0.001). The TS was higher in UA than MA and DC (p=0.004 and p<0.001 respectively). Conclusion: The expression of BMP-4 in the epithelium was higher in ameloblastoma compared to DCs. BMP-4 is a potential measure to differentiate different types of ameloblastoma and dentigerous cyst. The differentiation of these lesions is important as the right treatment plan changes according to the diagnosis.