Summary of Midface Reconstruction: Defects and Techniques

## Introduction Maxillary reconstruction deals with restoring the anatomy, function, and aesthetics of the midface after maxillary resections. This StudyFi material focuses on the classification of maxillectomy types, the goals of reconstruction, and the selection of reconstructive methods depending on the extent of the defect. > **Definition:** Maxillary reconstruction is the surgical restoration of bone and soft tissue structures of the maxilla to ensure ocular support, separation of the orbital and nasal/oral cavities, and restoration of both palatal and extraoral surfaces. ## Basic Classification of Defects Maxillectomies can be classified according to the extent of resection. Here, we will focus on types IIB, III (IIIA and IIIB), and IV, which typically require complex solutions. ### Type IIB – Extensive Palatal Defects - This type arises from the resection of more than 50% of the transverse portion of the palate or a significant part of the anterior arch. - Bone is needed for upper lip support and for the relationship of the alveolar arch. > **Definition:** An osteocutaneous flap is a free flap containing a bone segment and an adjacent skin/soft tissue component for the restoration of bony and mucocutaneous continuity. Practical Solution: - Flap of choice: radial forearm osteocutaneous “sandwich” flap. - The bone segment is shaped to reconstruct the alveolar arch and support the upper lip. - A thin, pliable skin paddle is wrapped around the bone to replace the palatal and nasal lining. Application: - If sufficient bone material is harvested, osseointegrated teeth can be implanted, or conventional prostheses can be fitted. ### Type III – Total Maxillectomy (All 6 Walls) These defects involve complete resection of the maxilla. They are divided into: - **Type IIIA**: orbital contents preserved - **Type IIIB**: orbital contents resected (extended maxillectomy) Reconstruction Goals for Both Subtypes: - Support of the globe - Closure of communication between the orbit and nasopharynx - Reconstruction of the palatal surface Type IIIA (Orbital Contents Preserved): - Need for a bone graft to reconstruct the orbital floor and maxillary prominences - Soft tissue coverage for the palate, nasal lining, and cheek Methods Used: - Bone grafts: split calvarial bone (calvarium), iliac crest, less commonly, split ribs - Soft tissue flap: rectus abdominis myocutaneous flap with one or more skin paddles (can be wrapped around a bone graft to separate the orbital contents from the oral cavity) - Alternative for patients unsuitable for free flaps: temporalis flap (requiring a concomitant palatal obturator) Practical Example: - Patient after total maxillectomy with preserved orbit: a split iliac crest graft is used to support the orbital floor, and a rectus abdominis myocutaneous flap covers the bone and fills the antral cavity, creating a watertight seal of the palate. Type IIIB (Orbital Contents Resected): - Goals: to close the palate, restore nasal lining, and reconstruct eyelids, cheek, and lip as needed; if the anterior cranial base is exposed, the brain must be covered - Flap of choice: rectus abdominis myocutaneous free flap with one or more skin paddles - Alternative: latissimus dorsi flap for large soft tissue volume, but less versatile in terms of multiple skin paddles ### Type IV – Orbitomaxillectomy - This involves resection of the superior five walls of the maxilla and typically the orbital contents, often exposing the dura and brain; the palate usually remains intact - These are large volume defects with extensive surface area requirements Solution: - Flap of choice: rectus abdominis flap with one or more skin paddles for external coverage and/or nasal lining - Attention must be paid to tightening the soft palate and restoring the buccal sulcus; if not adequately supported, the skin paddle can prolapse into the oral cavity. > **Definition:** A palatal obturator is a prosthetic device that temporarily or permanently