Between Safeguard and Constraint: Navigating Patient Autonomy in Protective Laws for Medical Assistance in Dying.

The maxilla is a key part of the facial skeleton. It has a complex three-dimensional structure with multiple processes and cavities. Maxillectomy is a common procedure used to treat maxillary diseases, including benign and malignant tumors, trauma, and congenital deformities []. Because the maxilla has a complex structure and is involved in key functions like facial support, breathing, chewing, and clinical procedures (such as dental implants and sinus treatments), its removal can affect a patient’s appearance and function and may lead to serious postoperative problems [, ]. However, Traditional approaches often leave a large defect in the maxilla after tumor removal. This can lead to severe postoperative complications, such as oronasal fistulas caused by the breakdown of the barrier between the mouth and nose, empty nose syndrome from nasal collapse, and facial sinking. These issues can severely affect patients’ quality of life and physical and mental health []. After maxillary tumor removal, besides the possible complications, repairing the bone defect is also a major challenge for patients. Maxillofacial repair, such as dental implants or bone reconstruction, is difficult to perform []. Using various vascularized bone-muscle composite flaps can better close off the mouth and nose and restore facial appearance. But, this approach involves more surgical trauma and higher risks. It also demands greater skill from the surgeon and better physical condition from the patient [, ]. Therefore, it is very meaningful to create a good seal between the mouth and nose and to establish favorable surgical conditions for the patient during the initial maxillectomy. The Schneiderian membrane, which is the lining of the maxillary sinus, closely covers the inner wall of the sinus. Traditional maxillectomy procedures often do not pay enough attention to preserving this membrane. Removing the maxilla also destroys the integrity of the Schneiderian membrane. This leads to loss of sinus function, affects nasal airflow and mucus clearance, and increases the risk of postoperative problems []. Multiple studies have shown that the Schneiderian membrane has the potential to form bone on its own. It can obtain mesenchymal stem cells (MSCs), which can turn into osteoprogenitor cells, from sources like the epithelial-mesenchymal transition (EMT) of the mucoperiosteal epithelium, the rich blood vessels in the lamina propria and the mucoperiosteum itself. With certain outside stimulation, the osteoprogenitor cells inside the membrane are activated. They mature and differentiate within the fibrin structure attached to the blood clot under the periosteum, forming the center of bone formation.