Analysis of the influence of residual alveolar bone height on sinus augmentation outcomes

Abstract

Maxillary sinus augmentation is a predictable implant site development technique for posterior atrophic maxillary ridges. However, graft consolidation requires adequate angiogenesis and migration of osteogenic cells from native bone. Therefore, the amount of residual bone height (RBH) may play a role in the rate of graft maturation. The purpose of this study was to analyze the influence of RBH in the histomorphometric outcomes of maxillary sinus augmentation procedures. Patients in need of sinus augmentation were recruited for the study. Customized radiographic guides were fabricated and a cone-beam computerized tomography scan was obtained at baseline. Two examiners measured RBH on the scans at the locations marked by the radiographic guide. Sinus grafting was performed by a lateral window approach using a particulated mineralized allograft. Patients were followed up for 6 months. At the time of implant placement, bone core biopsies were harvested using the radiographic guide, which was converted into a surgical guide. Samples were histomorphometrically analyzed. Proportion of vital bone (%VB), remaining allograft particles (%RA), and non-mineralized tissue (%NMT) were quantified. Categorical analysis of correlation of RBH (<4 or ≥4 mm) with%VB and%RA was performed using a statistical model. Twenty-one patients underwent sinus augmentation for a total of 21 sinuses. One patient developed an infection after grafting and was excluded. Histomorphometric analysis revealed that mean%VB was 20.47 ± 18.25, mean %RA was 29.04 ± 24.94, and average %NMT was 50.47 ± 12.76. No significant correlation between RBH and %VB (r = 0.016; P = 0.951), and RBH and % (r = 0.009; P = 0.971) was found. Similarly, categorical analysis of correlation showed no statistical significance. These findings suggest that the remaining alveolar bone height does not appear to influence the maturation and consolidation of an allograft in the maxillary sinus.