The goal of this study is to investigate the clinical efficacy of different maxillary sinus floor elevation procedures based on maxillary sinus anatomy.

The main questions it aims to answer are:

• How does the anatomical morphology of maxillary sinus affect postoperative bone resorption?
• How to select the appropriate maxillary sinus floor elevation procedure based on maxillary sinus anatomy? Preoperative, immediate postoperative, and six-month postoperative CBCT images of patients undergoing translateral maxillary sinus floor elevation or hydraulic transcrestal maxillary sinus floor elevation will be measured.

Inclusion Criteria:

• Patients undergoing translateral maxillary sinus floor elevation or hydraulic transcrestal maxillary sinus floor elevation in the maxillary molar region.
• Patients undergoing maxillary sinus floor elevationwith simultaneous implantation in the maxillary molar region，and having successful osseointegration after 6 months from surgery.
• Patients having CBCT examination for preoperative, the day of surgery, and six months after surgery.
• Patients treated between January 1, 2016 and June 30, 2024.

Exclusion Criteria:

• Patients having osteointegration failure within six months after surgery.
• Refusal to participate in the study.
• Other conditions deemed unsuitable for participation by the investigator.

Patients undergoing maxillary sinus floor elevation with simultaneous implantation in the maxillary molar region, and having successful osseointegration after 6 months from surgery.