Data collection will be done on all patients who underwent a lateral maxillary sinus floor augmentation in the Faculty of Dental Medicine, both in the Periodontology Department and in the Oral Surgery Department.

Pre-surgical residual bone height will be measured on patients with a preoperative CBCT, and marginal bone loss will be measured in patients with a postoperative periapical radiograph that dates at least 3 years after implant placement.

In contrast to other studies who only associated between the presurgical residual bone height and implant survival / success rate, this study design takes a more in depth approach and measures the exact marginal bone loss on each implant. In addition, other factors will be taken into consideration (implant type, smoking status, diabetes status) to eliminate any confounding factors.

Inclusion Criteria:

• All patients who underwent a lateral maxillary sinus floor augmentation using deproteinated bovine bone matrix (DBBM) at the faculty before 2022.
• Patients with pre-operative CBCT.
• Patients with no visible sinus infection in the pre-operative CBCT.

Exclusion Criteria:

• Patients who do not have a pre-operative CBCT.
• Patients who do not have a post-operative orthogonal periapical radiograph that dates at least 3 years after implant placement.
• Presence of inflammatory lesions at the surgical site (eg, sinusitis as assessed by CBCT).
• Cases with sinus perforation.
• History of radiation therapy in the head/neck region.
• Use of bisphosphonates

Patients from the Faculty of Dental Medicine at Saint Joseph University of Beirut who underwent a lateral maxillary sinus floor augmentation