upper lip, and the oral commissure. The two horizontal and three vertical buttresses of the maxilla are responsible for the projection of the midface and vertical facial height.

21.3 Repair of Orbital Defects

Orbital defects range from defects resulting from limited or subtotal maxillectomy to defects resulting from total maxillectomy with orbital exenteration. A varying number of adjacent structures are often excised in combination with the maxilla.

The principal objectives of orbital reconstruction are (1) to provide support to the orbital contents to avoid displacement of the globe and diplopia; (2) to prevent ascending infections by obliterating any communication between the orbit and the nose, the mouth, the nasopharynx, and the anterior skull base; (3) to reconstruct the palatal surface to enhance articulation and deglutition; (4) to reconstruct the lacrimal apparatus; and (5) to provide enough tissue volume to achieve facial symmetry and a good aesthetic result [1].

21.3.1 Overview of Approaches

The various approaches available for repair of orbital defects can be divided into two main categories: repair after maxillectomy with orbital exenteration and repair after maxillectomy without orbital exenteration. Reconstruction after total maxillectomy with preservation of the orbital contents is technically more challenging than reconstruction after maxillectomy combined with orbital exenteration.

21.3.1.1 Maxillectomy with Orbital Exenteration

Maxillectomy with orbital exenteration is a disfiguring and complex surgical procedure that is required when there is extensive invasion of cancer in the maxillary sinus with significant involvement of the orbital soft tissues. Given the frequent need for postoperative high-dose adjuvant radiation therapy, reconstruction usually requires grafting of free tissue flaps from distant donor sites, such as transverse rectus abdominis myocutaneous flaps and anterolateral thigh free flaps. The size of the defect dictates from where sufficient soft tissue can be harvested and transferred. It is possible to choose flaps that may allow for a concave orbital cavity so that the patient can use an orbital prosthesis if desired. In a recent study from M.D. Anderson Cancer Center, it was found that a radial forearm flap or a temporoparietal muscle flap may be the best choices in terms of potentially allowing for an orbital prosthesis. In some patients, especially those with complete obliteration of the orbital contents on the affected side, the choice of a free flap is limited to more bulky tissues, such as anterolateral thigh or abdominal flaps.