Abstract
Oral pyogenic granuloma or granuloma pyogenicum is a conspicuous lesion. The word pyogenic granuloma is a misterm since the situation is not related with pus and histologically does not exemplify a granuloma. An oral pyogenic granuloma is obvious to involve the gingiva generally. Extragingivally, it can present on the buccal mucosa, lips, tongue, and palate. A report of trauma is prevalent in such sites. The pathogenesis of the lesion is still unclear, although it was initially supposed to be a botryomycosis infection. It is suggested that etiology of pyogenic granuloma was the reaction of tissues to minor injury or chronic irritation, thus open a pathway for the entrance of nonspecific microorganisms, although microorganisms are not often expressed within the lesion. Hence, this review recapitulates all diverse concepts of pathogenesis associated with this most often and most mysterious lesion of the oral cavity.