Patients with insufficient bone volume in the posterior maxillary region can still have their missing teeth restored by dental implants. Generally speaking, if the bone volume is less than 4mm, the bone height can be increased by implanting bone powder while lifting the maxillary sinus externally, and depending on the situation, implants can be placed at the same time or in the second stage; if the bone volume is more than 4mm, the bone height can be increased by implanting bone powder while lifting the maxillary sinus internally, and generally implants can be placed at the same time. After maxillary sinus external lifting surgery, the local swelling and pain will be more obvious, while the reaction after internal lifting surgery is relatively light and generally does not affect daily life. Currently, this surgery is routinely performed in our hospital.