Myofibroblasts in calcifying odontogenic cyst and dentigerous cyst

Calcifying odontogenic cyst (COC) is an odontogenic cyst that sometimes shows aggressive behavior, while dentigerous cyst (DC) always has a benign nonaggressive course. There are evidences that myofibroblasts are involved in invasion and their role in biologic behavior of odontogenic cysts has been less understood. So, the aim of the present study was to compare the role of myofibroblasts in COC and DC. In this cross-sectional study, paraffin-embedded tissue blocks of 20 COCs and 20 DCs were studied. Four-micron sections were prepared from tissue blocks and stained with α-SMA antibody using immunohistochemistry. Percentages of myofibroblasts were semi quantitatively classified into negative (<5% of cells were positive), weak (5-50% cells were positive) and strong (>50% of cells were positive). Percentage of myofibroblasts was compared between COC and DC groups using t-test and Chi-Square statistical tests. Means of myofibroblasts percentages in COC and DC groups were respectively 35±33 and 32±30 that did not show significant difference between COC and DC groups (P=0.76). There was not any significant difference between COC and DC groups with respect to semi quantitative classification of percentage of myofibroblasts (P=0.62). Myofibroblasts probably do not play a significant role in different biologic behaviors of calcifying odontogenic and dentigerous cysts.