Study of polarization colour in the connective tissue stroma of the odontogenic lesions and to study the role of collagen fibers in the expansion of the lesion by using picrosirius red stain with polarizing microscope

To evaluate the nature of collagen fibers in odontogenic cysts & tumors by determining the birefringence using picrosirius red stain and polarizing microscope.

Is to examine the nature of collagen fibers

Is to evaluate the orientation of the collagen fibers

Is to correlate picrosirius red stain of collagen to biologic behaviour of the lesion.

Collagen fibers of 23 cases of odontogenic lesion including odontogenic tumors and cysts were studied by staining the sections with picrosirius red stain and examining under polarizing microscope.

66 percentage of the thin collagen fibers of the radicular cyst and odontogenic keratocyst exhibited green yellow birefringence.100 percent cases of the infected odontogenic keratocyst exhibited orangish yellow birefringence. The odontodenic tumors like Ameloblastoma, Keratocystic odontogenic tumor and Adenomatoid odontogenic tumor exhibits predominantly red colored birefringence. The predominant orange red birefringence exhibited in 33% of OKC, 66% of keratocystic odontogenic tumors 6% of infected OKC along with 66% cases of ameloblastoma and adenomatoid odontogenic tumors exhibited thick and tightly packed collagen fibers. Statistical analysis with one way ANOVA was significant with p<0.01. Moreover comparing polarization of collagen fibers with the duration of the lesion also gave statistically significant results.

The observations in the present study with the respect to the color profiles of the collagen fibers in these commonly occurring odontogenic lesions possibly explain the biological behaviour of the lesions. The predominant orange red birefringence in cysts like KCOT, OKC are same as in cases of the odontogenic tumors like ameloblastoma and adenomatoid odontogenic tumor. This may possibly explain the reason for the prognosis of red birefringence showing lesions which suggests that though the epithelium plays an important role in the pathogenesis of the lesions, even stroma is likely to play an equally important role in the pathogenesis and biological behaviour.