Desmoplastic Fibroma of the Mandible in a child presenting with TMJ dysfunction

background : Desmoplastic fibroma of bone is a rare intraosseous benign but locally aggressive tumor of connective tissue origin. The lesion may affect the metaphyses of the long bones but it may also involve the skull bones and more specifically the mandible, with most lesions appearing in the ramus-angle area. Treatment is surgical although additional chemotherapy or radiation has been applied. Case report : A 10-year-old boy initially presented with restriction and deviation of mouth opening. Clinical and radiological examination revealed a tumor-like lesion of the mandible extending into the soft tissues, which on biopsy proved to be a desmoplastic fibroma. Treatment : The surgical treatment included peripheral ostectomy of the mandible, via an intraoral approach, for the removal of the lesion and restoration of the bone defect with an iliac bone autograft. Follow-up : The high recurrence rate of this type of lesion, demands a strict follow-up schedule. In the case presented, 5 years post-operatively, there are no signs of local recurrence. Conclusion : Changes in mouth opening when not attributed to obvious reasons, such as trauma, should make a dentist suspicious and lead to further investigation. In the case presented, a central lesion was revealed in the radiograph and the patient was referred and treated early. Extended surgical removal of the tumor, with wide margins, proved to be the appropriate treatment.