Role of myofibroblasts and collagen quality in elaboration of debatable nature of odontogenic keratocyst

Odontogenic keratocyst (OKC) is one of the debatable odontogenic lesions. The need for more researches in order to determine the true nature of this lesion was one of the WHO’s recommendations in 2016. Stromal reactions to epithelial neoplasms are marked by the appearance of alpha smooth muscle actin (α-SMA) positive myofibroblasts (MFs). Stromal collagen has a vital role in pathogenesis of odontogenic lesions. Objectives: to compare the count of α-SMA positive MFs, collagen quality and packing in OKC, in relation to dentigerous cyst and ameloblastoma. Material and methods: α-SMA immunohistochemically positive MFs count, as well as the fraction of yellow-green fibers to detect the collagen quality and packing using picrosirius red staining with polarized light microscope, were compared in 11 samples of each of ameloblastoma, OKC and dentigerous cyst. Statistical analysis was performed. Results: the average number of MFs were 53.7, 41.9 and 11.3 in ameloblastoma, OKC and dentigerous cysts respectively with statistically significant differences (P-value