Spontaneous Regression of Ossifying Fibroma in the Oral and Maxillofacial Region: A Rare Case With 4-Year Follow-Up.

The case presented in this study is a rare instance of an ossifying fibroma (OF), a type of benign fibro-osseous lesions, spontaneously regressed without surgical intervention. A 9-year-old boy with an intraosseous lesion in the left maxilla was diagnosed as OF. The surgeon suggested surgical excision, but due to personal reasons, the patient and his parents deferred the surgery and opted for regular follow-up. During a 4-year follow-up, the surgeon found that the lesion had significantly decreased in size and the facial deformity had remitted. At the latest follow-up, the deformity of his left face became almost unnoticeable, and the lesion seemed to be subtle on cone-beam computed tomography images. This case highlights the possibility of spontaneous regression of OF. This phenomenon may occur due to the teeth eruption, which can lead to the formation of periodontal ligaments and engage the regression of OF.