33rd Annual Scientific Meeting proceedings

Introduction: Ossifying fibromas are mostly described in the rostral part of the mandibula. Appearing more caudal in the head, removal becomes more difficult.

Case description: A 4 year-old warmblood mare was referred to the clinic for a slow growing mass on the right side of the maxilla since 3 years. CT-scan revealed a highly expansive and extending mass into the right maxillary sinus with loss of the alveolar bone of the maxillary dental arch. The mass was penetrating into the oral cavity and was in direct contact with de opposite mandibular teeth. Based on this image, suspected diagnosis of a juvenile ossifying fibroma was made. Post-operative histopathology confirmed the diagnosis.

Results: Under general anesthesia, the mass was surgically completely removed. In order to achieve complete excision, the alveolar bone of the maxillary dental arch, together with all teeth (106-111) were removed. Complete closure of the large defect between right maxillary sinus and the oral cavity was accomplished by suturing the palate to the cheek mucosa. For the second layer masseter and levator nasolabialis muscle were used. Postoperatively, the horse was fed by nasogastric tube during 2 weeks and healed without complications. Complete remission was confirmed after 1 year by control CT-scan.

Conclusion: CT scan provides detailed information about the extend and exact location of the tumor which is crucial in the successful surgical management of large benign tumors at the level of the head.