Ossifying Fibroma of the Mandible: A Case Report Using Vascularized Free Fibula Flap Reconstruction

Summary:

We report a case of ossifying fibroma of the mandible in a 38-year-old woman. The mandibular resection involved the disarticulation of the condyle while preserving the articular disc. The segmental bony defect was then reconstructed with free fibula flap; the additional contouring of the distal fibular flap was performed during surgery to restore the patient’s condylar function. A 2-year follow-up revealed the maintenance of excellent functional and aesthetic outcomes.

Ossifying fibroma (OF) is classified as a benign bone neoplasm. In 2005, the World Health Organization classified OF to be synonymous with cementifying fibroma and cemento-ossifying fibroma. Complete removal of the lesion is recommended once the diagnosis is established.¹

Based on the 8 permutations described (C, L, H, LC, HC, LCL, HCL, and HH), our patient belonged to the H group where the “hemimandibular” defect involved the resection of the lateral mandible and the condyle.²

The condylar reconstruction typically consists of the sole use of reconstruction plates, autogenous bone grafting, or pedicled bone grafting.

We report a case of OF of the mandible in a 38-year-old patient. The treatment involved condylar resection and mandibular reconstruction with free fibular flap. Furthermore, the distal end of the flap was contoured to restore the patient’s condylar function. Our 2-year follow-up revealed excellent functional and aesthetic outcomes for the patient.

CASE REPORT

A 38-year-old woman presented with a complaint of swelling and facial asymmetry in the left angle of the mandible that started 3 months prior.

Panoramic radiograph revealed a large intraosseous lesion with radiopacity from the left angle of the mandible to the condyle. A biopsy of the lesion and the subsequent histological test confirmed the diagnosis of OF (Fig. 1).

Fig. 1.

A large intraosseous lesion with radiopacity from the left angle of the mandible to the condyle on the preoperative panorex.

Segmental mandibulectomy was done and resulted in a bone defect 7 cm in length; the condyle was disarticulated from the joint while the articular disc was preserved.

A free fibular flap was harvested from the patient’s left leg, and the distal end of the fibula was rounded to simulate the contour of a condyle. The masseter muscle was sutured to the angle of the reconstruction plate to fix the distal end into the glenoid fossa.

The postoperative cone beam computed tomography showed the flap inset and its position to be within the glenoid fossa. Intermaxillary fixation was used during the initial 4 weeks of postoperative period to maintain correct occlusion for the patient. The patient was then followed up for 2 years showing excellent functional and aesthetic results (Figs. 2, 3). The cone beam computed tomography showed that the distal end of the fibula positioned appropriately in the glenoid fossa (Fig. 4).

Fig. 2.

Postoperative dental occlusion.

Fig. 3.

The mouth opening was preserved.

Fig. 4.

Mandibular and condylar reconstruction by fibular flap and postoperative 2-year follow-up on cone beam computed tomography.

DISCUSSION

The differential diagnosis for OF includes fibrous dysplasia, odontogenic cysts, chondrosarcoma, osteosarcoma, and squamous cell carcinoma. Generally, the recommended treatment for OF is complete excision of the tumor. The entire tumor should be removed along with the involved site.

In the event where the tumor directly invades the condyle, incorporating the native condyle into the free graft would not be feasible; out of necessity, surgeons have placed the distal end of the fibular flap directly into the glenoid fossa with or without contouring. To optimize the function of the temporomandibular joint after condylar reconstructions, preserving the articular disc after disarticulation then becomes critical. Wax et al reported that in a series of 17 reconstructions in which a suture was placed to stabilize the preserved disc against the upper end of the fibula flap, patients were able to maintain excellent functional and cosmetic results.^3,4 In a follow-up study (average follow-up of 31 months) based on radiographic and clinical examination, Guyot et al³ evaluated the surgical and functional outcomes of 11 patients who had undergone temporomandibular joint reconstruction with a free fibular flap following condylar resection; they reported that patients maintained sufficient mouth opening and an absence of joint ankylosis. In addition, they observed structural remodeling and rounding of the reconstructed condyle in most patients during follow-up. The authors suggested that the disc preservation might have played an important role in controlling the form of the mandibular condyle through remodeling.³

In the management of our patient with OF, our surgical approach was supported by sound evidence as mentioned previously. The reconstructed condyle maintained appropriate position in the glenoid fossa, the interincisal opening was preserved, and the occlusion was unchanged.^5–7 The patient was followed up for 2 years with promising prognosis and excellent functional and aesthetic outcomes.

PATIENT CONSENT

The patient provided written consent for the use of her image.