A preliminary imaging observation of the newly formed maxillary sinus floor after lateral maxillary sinus floor elevation

[Objective:] To explore the imaging features and clinical significance of the white blocking line appearing on the newly formed maxillary sinus floor surface after lateral maxillary sinus floor elevation. [Methods:] A total of 41 patients who had lateral maxillary sinus floor elevation and bone grafting were followed up for 8 to 64 months. Cone beam CT (CBCT) was used to observe the changes in the bone grafts. Systemic information (such as smoking, diabetes) and local conditions (such as sinus membrane thickening or maxillary sinus cyst) were recorded. [Results:] A total of 45 sinuses in 41 patients had lateral maxillary sinus floor elevation and received bone grafting. Among them, 6 sinuses in 6 patients (with an incidence rate of 13.3%) showed the imaging changes of the white blocking line on the newly formed maxillary sinus floor surface (this radiographic feature is hereinafter referred to as the "analogous bony white line", and the formed structure is hereinafter referred to as the "cortical-like structure"). The formation time of the cortical-like structure is 10 to 36 months after the operation. In 2 patients, the formation of the cortical-like structure was detected 10 months after the operation, and the thickening of the cortical-like structure was observed at 26 months and 30 months after the operation respectively. [Conclusion:] After lateral maxillary sinus floor elevation, in some cases, the cortical-like structure will appear on the newly formed surface of the maxillary sinus floor during the process of osseointegration, with progressive thickening over time.