Peripheral ossifying fibroma or ossifying fibroma is a pathological condition of the mouth that occurs due to overgrowth of the tissues of gingivitis due to trauma or irritation. It is a non-elastic enlargement of the gingival that is known as reactive hyperplastic irritating lesion. Because it affects the gingiva, this condition is also related to two other diseases, however they both do not occur together. The three diseases are associated with each other as they frequently occur on the gingiva. The other two diseases are pyongenic granuloma and peripheral giant cell granuloma. Ossifying fibroma is known to arise from gingival periosteum, corium and periodontal ligament.