Osteosarcoma is a bone tumor that consists of malignant cells that produce immature bone. Is a bone tumor that develops during periods of rapid growth in adolescents and young adults. It is the most common type of bone cancer in children and adolescents. The diagnosis and treatment of patients with osteosarcoma requires a multidisciplinary team approach. Resection of maxillary tumours remains a surgical challenge due to the possible aesthetic and functional secuelae. We present herein the case of a 15 year-old female with an osteoblastic osteosarcoma of the left maxilla. It was treated with eight cycles of neoadjuvant chemotherapy, followed by a total left maxillectomy. Resection was performed through a modified Ferguson-Weber approach, using a titanium mesh to reconstruct the orbital base and the maxillary process. A palatal obturator was placed at the same time. The use of a three-dimensional model by stereolithography is extremely helpful in planning and performing the maxillectomy, as well as the facial reconstruction