RECONSTRUCTION OF THE MAXILLA AND SKULL BASE
ERIC G. HALVORSON, DUC T. BUI, AND PETER G. CORDEIRO
Following vertical rectus abdominis myocutaneous flap coverage of a type IIIB defect, this patient had too much bulk in the orbit preventing placement of an ocular prosthesis. Direct excision combined with liposuction improved flap contour and provided an appropriate platform for prosthetic fitting. A staged “nasolabial” flap was elevated to increase the oral aperture and add intraoral lining. C and D. An ocular prosthesis greatly improves the aesthetic outcome for patients undergoing coverage of type IIIB or IV defects with large soft-tissue flaps. An adequate orbital hollow should be recessed at least 1 cm from the normal cornea.
Maxillectomy and midfacial defects are classified into four types of defects based on the extent of maxillary resection. This classification allows for a simplified approach to midface reconstruction. The algorithm is based on the type of maxillary defect, which will usually have specific skin, soft-tissue, palatal, orbital floor, and bony structure deficits. Bone reconstruction is best accomplished with bone grafts for the floor of the orbit and a vascularized bone flap for the maxillary arch. Soft-tissue and skin coverage is commonly provided by free flaps. The choice of flap is determined by the surface area and tissue volume requirements. Large surface area and small- to medium-volume defects are best reconstructed with radial forearm fasciocutaneous or osteocutaneous flaps. Large-volume and medium to large surface area defects are best reconstructed with rectus abdominis free flaps. Other options include the fibula and anterolateral thigh flaps. Critical midfacial structures, such as the lips, eyelids, and nose, should be addressed separately, using local flaps if possible. The majority of patients whose maxillary defects are reconstructed using free tissue transfers have remarkably good function. Aesthetic results are mainly dependent on whether the orbital contents are removed and on the extent of external skin resection.