Bone Quality in Resorbed Posterior Maxilla Affects Osteogenesis After Sinus Floor Augmentation: A Retrospective Analysis

INTRODUCTION AND AIMS: Compromised bone quality and quantity in the posterior maxilla are widely recognised as significant risk factors for implant failures. This study aimed to (1) assess the bone quality of the resorbed posterior maxilla both radiographically and histologically and (2) evaluate the impact of native alveolar bone quality on osteogenesis following maxillary sinus floor augmentation (MSFA). METHODS: Patients presenting advanced posterior maxillary atrophy (residual bone height ≤ 4 mm) underwent MSFA via a lateral window approach using deproteinised bovine bone matrix (DBBM). Bone core biopsies were collected during second-stage implant placement for histological analyses. Preoperative cone-beam computer tomography (CBCT) images were used to classify bone quality based on cortical bone configuration. Multiple linear regression was employed to identify factors influencing osteogenesis. RESULTS: A total of 190 sinuses from 176 patients (96 males/80 females, mean age: 45.77 ± 4.13 years) underwent MSFA and biopsy. Radiographic analysis revealed the presence of bicortical bone in 42.21% of the maxillary ridges, unicortical bone in 25.97%, no cortical bone in 19.48% and sinus floor-crestal bone fusion in 12.34%. Histologically, native bone comprised 40.01% ± 14.85% of mineralised trabeculae while newly formed bone accounted for 18.77% ± 5.69% in the DBBM grafted areas. A significant positive correlation was observed between native bone trabecula percentage and new bone formation (r = 0.23, P = .04). No significant associations were found with age, sex, healing time or radiographic alveolar type (P > .05). CONCLUSION: Greater density of native trabecular bone may contribute to enhanced osteogenesis following MSFA. CLINICAL RELEVANCE: This study enhances our understanding of the bone characteristics of the resorbed posterior maxilla. It emphasises the need to consider the bone quality of the recipient site before conducting a MSFA for determining the surgical procedure and predicting the prognosis.