Table 1.

Histopathologic grading criteria by Pindborg and Sirsat [4]

Very early stage (grade I)	Early stage (grade II)	Moderately advanced stage (grade III)	Advanced stage (grade IV)
Presence of fine fibrillar collagen with marked edema	Early hyalinization in the juxtra epithelial region	Collagen is moderately hyalinised	Collagen is completely hyalinised
Extensive fibroblastic response	Plump young fibroblasts in moderate numbers	Fibroblastic response is less evident consisting of only adult fibrocytes	Hyalinised areas are devoid of fibroblasts
Blood vessels are normal or dilated and congested	Blood vessels are dilated and congested	Blood vessels are normal or constricted	Blood vessels are completely obliterated
Inflammatory cells usually neutrophils and occasional eosinophils	Inflammatory cells are lymphocytes, eosinophils and occasional plasma cells	Inflammatory cells are lymphocytes and plasma cells with occasional eosinophil	Inflammatory cells are lymphocytes and plasma cells