title: Analysis of the influence of residual alveolar bone height on sinus augmentation outcomes.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI 48109-1078, USA.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Avila-Ortiz
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Neiva
authors.forename: Pablo
authors.initials: P
authors.lastname: Galindo-Moreno
authors.forename: Ivan
authors.initials: I
authors.lastname: Rudek
authors.forename: Erika
authors.initials: E
authors.lastname: Benavides
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging* / Q000473:pathology; D000539:Alveolar Process / Q000000981:diagnostic imaging* / Q000473:pathology; D001706:Biopsy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010347:Patient Care Planning; D011183:Postoperative Complications; D059546:Sinus Floor Augmentation / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome